the silver labeo ( labeo ruddi ) is an african species of freshwater fish in the family cyprinidae .

it can reach a length up to 30 cm and weight of 1 kg .

silver labeo

howe p , dobson s ( 2002 ) silver and silver compounds : environmental aspects . concise international chemical assessment document 44 . world health organization , geneva
figure 4 : recorded presence of silver carps in fish culture stations and rivers .
drake pl , hazelwood kj ( 2005 ) exposure - related health effects of silver and silver compounds : a review . ann occup hyg 49 ( 7 ) : 575–585 . doi :
reid , g . m . , 1985 . a revision of african species of labeo ( pisces : cyprinidae ) and a re - definition of the genus . verlag von j . cramer , braunschweig . 322 p . ( ref . 1440 )
silver labeos can be found in calm , slow moving bodies of water that have thick , muddy bottoms .
silver carp are basically phytoplankton feeders and after introduction will compete with other species for this food source . silver carp however will have little effect on the habitat and their overall negative impact on the ecosystem might be limited .
as a process variable in silver nanoparticles synthesis . j nanomedicine res 1 ( 2 ) : 00011 . doi :
sohn ek , johari sa , kim tg , kim jk , kim e , lee jh , chung ys , yu ij ( 2015 ) aquatic toxicity comparison of silver nanoparticles and silver nanowires . biomed res int 1–16 . doi :
habitat : silver labeos can be found in calm , slow moving bodies of water that have thick , muddy bottoms . distribution : silver labeos can be found in throughout south africa namely limpopo etc . bait : favours small , meaty baits . more
ahamed m , alsalhi ms , siddiqui mk ( 2010 ) silver nanoparticle applications and human health . clin chim acta 411 ( 23–24 ) : 1841–1848 . doi :
benn tm , westerhoff p ( 2008 ) nanoparticle silver released into water from commercially available sock fabrics . environ sci technol 42 ( 11 ) : 4133–4139 . doi :
iravani s , korbekandi h , mirmohammadi sv , zolfaghari b ( 2014 ) synthesis of silver nanoparticles : chemical , physical and biological methods . res pharm sci 9 ( 6 ) : 385–406
hsu sl - c , wu r - t ( 2011 ) preparation of silver nanoparticle with different particle sizes for low - temperature sintering . in : 2010 international conference on nanotechnology and biosensors ipcbee
bar‐ilan o , albrecht rm , fako ve , furgeson dy ( 2009 ) toxicity assessments of multisized gold and silver nanoparticles in zebrafish embryos . small 5 ( 16 ) : 1897–1910 . doi :
tran qh , le a - t ( 2013 ) silver nanoparticles : synthesis , properties , toxicology , applications and perspectives . adv neural sci nanosci nanotechnol 4 ( 3 ) : 033001 . doi :
ahmed s , ahmad m , swami bl , ikram s ( 2015 ) a review on plants extract mediated synthesis of silver nanoparticles for antimicrobial applications : a green expertise . j adv res . doi :
levard c , hotze em , lowry gv , brown ge ( 2012 ) environmental transformations of silver nanoparticles : impact on stability and toxicity . environ sci technol 46 ( 13 ) : 6900–6914 . doi :
arora s , jain j , rajwade j , paknikar k ( 2009 ) interactions of silver nanoparticles with primary mouse fibroblasts and liver cells . toxicol appl pharmacol 236 ( 3 ) : 310–318 . doi :
schrand am , braydich - stolle lk , schlager jj , dai l , hussain sm ( 2008 ) can silver nanoparticles be useful as potential biological labels ? nanotechnology 19 ( 23 ) : 235104 . doi :
zhornik e , baranova l , drozd e , sudas m et al ( 2014 ) silver nanoparticles induce lipid peroxidation and morphological changes in human lymphocytes surface . biophysics 59 ( 3 ) : 380–386 . doi :
the group of the chinese carp , the grass carp ctenopharyngodon idella the silver carp , hypophtalmichthys molitrix , and the bighead carp , hypophthalmichthys nobilis , have been and are being used inside the drainage basin of the limpopo . in south africa the silver carp and grass carp have been stocked in the arabie dam near marble hall on the olifants river , while stocks of all three species are being kept at the mapapa station on the elefantes river near chokwe in mozambique . grass carp were introduced with the objective to control excessive aquatic vegetation in impoundments and irrigation canals , while the silver carp was introduced to increase fish production from these waters .
khan s , jabeen f , qureshi na , asghar ms , shakeel m , noureen a ( 2015 ) toxicity of silver nanoparticles in fish : a critical review . j bio environ sci 6 ( 5 ) : 211–227
sung jh , ji jh , yoon ju , kim ds et al ( 2008 ) lung function changes in sprague–dawley rats after prolonged inhalation exposure to silver nanoparticles . inhal toxicol 20 ( 6 ) : 567–574 . doi :
devi gp , ahmed kba , varsha ms , shrijha b , lal ks , anbazhagan v , thiagarajan r ( 2015 ) sulfidation of silver nanoparticle reduces its toxicity in zebrafish . aquat toxicol 158 : 149–156 . doi :
wijnhoven sw , peijnenburg wj , herberts ca , hagens wi et al ( 2009 ) nano - silver—a review of available data and knowledge gaps in human and environmental risk assessment . nanotoxicology 3 ( 2 ) : 109–138 . doi :
satyavani k , gurudeeban s , ramanathan t , balasubramanian t ( 2011 ) biomedical potential of silver nanoparticles synthesized from calli cells of citrullus colocynthis ( l . ) schrad . j nanobiotechnol 9 ( 43 ) : 2–8 . doi :
larese ff , d’agostin f , crosera m , adami g , renzi n , bovenzi m , maina g ( 2009 ) human skin penetration of silver nanoparticles through intact and damaged skin . toxicology 255 ( 1 ) : 33–37 . doi :
blaser sa , scheringer m , macleod m , hungerbühler k ( 2008 ) estimation of cumulative aquatic exposure and risk due to silver : contribution of nano - functionalized plastics and textiles . sci total environ 390 ( 2 ) : 396–409 . doi :
paulraj p , janaki n , sandhya s , pandian k ( 2011 ) single pot synthesis of polyaniline protected silver nanoparticles by interfacial polymerization and study its application on electrochemical oxidation of hydrazine . colloids surf a physicochem eng asp 377 ( 1 ) : 28–34 . doi :
gliga ar , skoglund s , wallinder io , fadeel b , karlsson hl ( 2014 ) size - dependent cytotoxicity of silver nanoparticles in human lung cells : the role of cellular uptake , agglomeration and ag release . part fibre toxicol 11 ( 11 ) : 1–17 . doi :
grass carp and silver carp normally do not breed outside their natural range as they require special environmental conditions for successful breeding . despite these specific requirements , these species have established breeding populations in several rivers in asia , europe and north america . it has been observed in south africa that grass carp develop to a point of breeding readiness and remain in this stage throughout the season . silver carp have already reproduced in the arabie dam , have established a breeding population in the limpopo system , and have been recorded well up into the limpopo river itself ( figure 4 ) .
piao mj , kang ka , lee ik , kim hs , kim s , choi jy , choi j , hyun jw ( 2011 ) silver nanoparticles induce oxidative cell damage in human liver cells through inhibition of reduced glutathione and induction of mitochondria - involved apoptosis . toxicol lett 201 ( 1 ) : 92–100 . doi :
with the removal of the vegetation through grass carp grazing and the resulting increase in turbidity , the aquatic habitat generally degrades and aquatic life will be negatively affected . so far as is known , the grass carp have not reproduced in the limpopo system but , seen the reproduction of silver carp , this possibility should not be ignored .
html public
- / / w3c / / dtd xhtml 1 . 0 strict / / en
urltoken
thank you for taking the time to provide feedback on the iucn red list of threatened species website , we are grateful for your input .
two distinct geographic populations exist . it was described from the limpopo river system in south africa and is also recorded from the cunene river on the angolan - namibian border . the taxonomic status of the cunene population needs examinaion .
snoeks , j . ( freshwater fish red list authority ) & darwall , w . ( freshwater biodiversity assessment unit )
justification : although not particularly common it is widespread within two major river basins . the impacts of dams to this migratory species is so far not known . however , it is typically found in low - veld reaches of rivers and so presumably impacts are relatively minor .
low - veld sections of the limpopo and incomati rivers ( south africa , swaziland and mozambique ) . a single record from the lower mbuluzi river in swaziland . a northern population is known from the cunene river on the angolan - namibian border .
very little information available for this species . said to be fairly common in the umzingwane ( limpopo ) river , zimbabwe ( bell - cross and minshull 1988 ) . in most other regions it appears to be rare .
deeper waters in or associated with main river channels and off channel pools . sand or mud substrates are typical . particularly common in seasonal river e . g . the shingwedzi river , kruger park , south africa .
to make use of this information , please check the < terms of use > .
freshwater ; benthopelagic ; ph range : 7 . 0 - ? ; dh range : 10 - 15 ; potamodromous ( ref . 51243 ) . tropical ; 23°c - 27°c ( ref . 2059 ) ; 13°s - 26°s
africa : within the drainage basin of the limpopo and incomati , as well as the cunene ( ref . 7248 ) but not in the pongolo .
maturity : l m ? range ? - ? cm max length : 30 . 0 cm sl male / unsexed ; ( ref . 7248 ) ; max . published weight : 1 . 0 kg ( ref . 7248 )
habitat preference is warm middle and low veldt streams and larger pools over muddy bottoms ( ref . 1440 ) . feeds on organic sediments . moves up rain - swollen rivers to breed ( ref . 7248 ) .
phylogenetic diversity index ( ref . 82805 ) : pd 50 = 0 . 5000 [ uniqueness , from 0 . 5 = low to 2 . 0 = high ] .
bayesian length - weight : a = 0 . 00832 ( 0 . 00356 - 0 . 01943 ) , b = 3 . 09 ( 2 . 88 - 3 . 30 ) , in cm total length , based on lwr estimates for this ( sub ) family - body shape ( ref . 93245 ) .
resilience ( ref . 69278 ) : medium , minimum population doubling time 1 . 4 - 4 . 4 years ( preliminary k or fecundity . ) .
vulnerability ( ref . 59153 ) : moderate to high vulnerability ( 45 of 100 ) .
habitat preference is warm middle and low veldt streams and larger pools over muddy bottoms ( ref . 1440 ) . feeds on organic sediments . moves up rain - swollen rivers to breed ( ref . 7248 ) .
eol content is automatically assembled from many different content providers . as a result , from time to time you may find pages on eol that are confusing .
to request an improvement , please leave a comment on the page . thank you !
html public
- / / w3c / / dtd xhtml 1 . 0 transitional / / en
urltoken
html public
- / / w3c / / dtd xhtml 1 . 0 strict / / en
urltoken
, ph range : 7 . 0 , dh range : 10 - 15 environment .
confused by a class within a class or an order within an order ? please see our brief essay .
to cite this page : myers , p . , r . espinosa , c . s . parr , t . jones , g . s . hammond , and t . a . dewey . 2018 . the animal diversity web ( online ) . accessed at https : / / animaldiversity . org .
disclaimer : the animal diversity web is an educational resource written largely by and for college students . adw doesn ' t cover all species in the world , nor does it include all the latest scientific information about organisms we describe . though we edit our accounts for accuracy , we cannot guarantee all information in those accounts . while adw staff and contributors provide references to books and websites that we believe are reputable , we cannot necessarily endorse the contents of references beyond our control .
this material is based upon work supported by the national science foundation grants drl 0089283 , drl 0628151 , due 0633095 , drl 0918590 , and due 1122742 . additional support has come from the marisla foundation , um college of literature , science , and the arts , museum of zoology , and information and technology services .
rafinesque , 1820 ) . ecotoxicol environ saf 74 ( 4 ) : 675–683 . doi :
woodrow wilson d woodrow wilson d ( 2016 ) nanotechnology consumer product inventory [ cited 2016 28 april ] . available from :
nowack b , krug hf , height m ( 2011 ) 120 years of nanosilver history : implications for policy makers . environ sci technol 45 ( 4 ) : 1177–1183 . doi :
hurst sj , lytton - jean ak , mirkin ca ( 2006 ) maximizing dna loading on a range of gold nanoparticle sizes . anal chem 78 ( 24 ) : 8313–8318 . doi :
reddy g , joy j , mitra t , shabnam s , shilpa t ( 2012 ) nanosilver review . int j adv pharm 2 : 9–15
thakkar kn , mhatre ss , parikh ry ( 2010 ) biological synthesis of metallic nanoparticles . nanomedicine 6 ( 2 ) : 257–262 . doi :
awasthi kk , awasthi a , bhoot n , john p , sharma sk , awasthi k ( 2013 ) antimicrobial properties of electro - chemically stabilized organo - metallic thin films . adv electrochem 1 ( 1 ) : 42–47 . doi :
smith ic , carson bl ( 1977 ) trace metals in the environment , vol 1 . arbor science publishers , usa
luoma sn , rainbow ps , luoma s ( 2008 ) metal contamination in aquatic environments : science and lateral management . cambridge university press , cambridge
hussain s , hess k , gearhart j , geiss k , schlager j ( 2005 ) in vitro toxicity of nanoparticles in brl 3a rat liver cells . toxicol in vitro 19 ( 7 ) : 975–983 . doi :
l . biol trace elem res 162 ( 1–3 ) : 333–341 . doi :
braydich - stolle l , hussain s , schlager jj , hofmann m - c ( 2005 ) in vitro cytotoxicity of nanoparticles in mammalian germline stem cells . toxicol sci 88 ( 2 ) : 412–419 . doi :
park b , martin p , harris c , guest r , whittingham a , jenkinson p , handley j ( 2007 ) initial in vitro screening approach to investigate the potential health and environmental hazards of envirox™—a nanoparticulate cerium oxide diesel fuel additive . part fibre toxicol 4 ( 12 ) : 4–12 . doi :
kumar pss , sivakumar r , anandan s , madhavan j , maruthamuthu p , ashokkumar m ( 2008 ) photocatalytic degradation of acid red 88 using au–tio 2 nanoparticles in aqueous solutions . water res 42 ( 19 ) : 4878–4884 . doi :
kataria n , kataria ak , pandey n , gupta p ( 2010 ) serum biomarkers of physiological defense against reactive oxygen species during environmental stress in indian dromedaries . hvm bioflux 2 ( 2 ) : 55–60
) : histological and biochemical studies . eur j exp biol 3 ( 2 ) : 285–289
rao r , møller im ( 2011 ) pattern of occurrence and occupancy of carbonylation sites in proteins . proteomics 11 ( 21 ) : 4166–4173 . doi :
abreu rd , morais ca ( 2010 ) purification of rare earth elements from monazite sulphuric acid leach liquor and the production of high - purity ceric oxide . miner eng 23 ( 6 ) : 536–540 . doi :
payá m , halliwell b , hoult j ( 1992 ) interactions of a series of coumarins with reactive oxygen species : scavenging of superoxide , hypochlorous acid and hydroxyl radicals . biochem pharmacol 44 ( 2 ) : 205–214 . doi :
peixoto al , pereira - moura mvl ( 2008 ) a new genus of monimiaceae from the atlantic coastal forest in south - eastern brazil . kew bull 63 ( 1 ) : 137–141 . doi :
habig wh , pabst mj , jakoby wb ( 1974 ) glutathione s - transferases the first enzymatic step in mercapturic acid formation . j biol chem 249 ( 22 ) : 7130–7139
jollow d , mitchell j , na z , gillette j ( 1974 ) bromobenzene - induced liver necrosis . protective role of glutathione and evidence for 3 , 4 - bromobenzene oxide as the hepatotoxic metabolite . pharmacology 11 ( 3 ) : 151–169 . doi :
bergmeyer h - u ( 2012 ) methods of enzymatic analysis . elsevier , burlington
wilchek m , bayer ea ( 1990 ) introduction to avidin - biotin technology . methods enzymol 184 : 5–13 . doi :
( cotton ) extract as stabilizing agent and assessment of its in vitro biomedical potential . ind crops prod 55 : 1–10 . doi :
krishnan r , maru gb ( 2006 ) isolation and analyses of polymeric polyphenol fractions from black tea . food chem 94 ( 3 ) : 331–340 . doi :
( hamilton , 1822 ) . colloids surf a physicochem eng asp 439 : 184–192 . doi :
mulvaney p ( 1996 ) surface plasmon spectroscopy of nanosized metal particles . langmuir 12 ( 3 ) : 788–800 . doi :
nel a , xia t , mädler l , li n ( 2006 ) toxic potential of materials at the nanolevel . science 311 ( 5761 ) : 622–627 . doi :
simonian n , coyle j ( 1996 ) oxidative stress in neurodegenerative diseases . annu rev pharmacol toxicol 36 ( 1 ) : 83–106 . doi :
van der oost r , beyer j , vermeulen np ( 2003 ) fish bioaccumulation and biomarkers in environmental risk assessment : a review . environ toxicol pharmacol 13 ( 2 ) : 57–149 . doi :
khan ms , jabeen f , asghar ms , qureshi na , shakeel m , noureen a , shabbir s ( 2015 ) role of nao - ceria in the amelioration of oxidative stress : current and future applications in medicine . int j biosci 6 ( 8 ) : 89–109 . doi :
thapa b , walia a ( 2007 ) liver function tests and their interpretation . indian j pediatr 74 ( 7 ) : 663–671
de miranda cabral gontijo am , barreto re , speit g , valenzuela reyes va , volpato gl , favero salvadori dm ( 2003 ) anesthesia of fish with benzocaine does not interfere with comet assay results . mutat res genet toxicol environ mutagen 534 ( 1 ) : 165–172 . doi :
khan , m . s . , qureshi , n . a . , jabeen , f . et al . biol trace elem res ( 2017 ) 176 : 416 . urltoken
copyright © 1999 - 2018 john wiley & sons , inc . all rights reserved
enter your email address below . if your address has been previously registered , you will receive an email with instructions on how to reset your password . if you don ' t receive an email , you should register as a new user
javascript is disabled on your browser . please enable javascript to use all the features on this page .
exposure to these particles causes down - regulation of gene expression in the liver .
copyright © 2018 elsevier b . v . or its licensors or contributors . sciencedirect ® is a registered trademark of elsevier b . v .
please return any fish that you are not planning to eat yourself , back to the river immediately .
not more than 5 bream per fisherman is allowed , bream smaller than 15cm must be released .
html public
- / / w3c / / dtd html 4 . 0 transitional / / en
river systems are in many cases not confined to one country . activities in a river catchment may therefore have a direct effect in other countries . co - operation between countries concerning these activities is thus crucial for sustainable management of the river resources . cross border activities include water abstraction , pollution , river siltation , catchment deforestation , etc . , but also include the introduction of aquatic species .
all over the world aquatic species have been introduced and translocated for the purpose of improving the production from aquatic systems . some of these introductions have led to increased production , while many of them have not had the desired effect . conversely , several introductions have had negative impacts on the natural habitat by displacing indigenous aquatic species directly through predation or competition as well as indirectly by changing the aquatic environment .
aquatic ecosystems are complex and the understanding of various systems is still limited . the possible effects of any management practice are therefore difficult to predict , while their impact may be detrimental to the ecosystem , as well as to the biodiversity of the overall system .
a technical consultation on species for small reservoir fisheries and aquaculture in southern africa was held in november 1994 in livingstone , zambia and was attended by 52 participants from within and outside the region . this consultation reviewed the situation regarding the introductions of species and recommended that the inter - country co - operation in relation to the management of shared water systems should improve , and consultations between the countries should be formalised .
during the present review the factors influencing fish distribution were assessed . the status of exotic introductions in the limpopo river and the official status of the individual countries sharing its catchment were reviewed , and discussed in consultation with key persons from the region . list of participants is given in appendix 1 . the information presented in this report is a compilation of views , experiences and results of discussions from these participants .
rivers transport water from rainfall towards points of lowest altitude . in most cases the water is ultimately transported to the oceans , although internal catchment basins exist . before reaching the oceans , different rivers join each other making a dendritic arrangement of streams throughout the drainage basin . each river system drains part of a continent , the drainage systems in southern africa are given in figure 1 .
rivers can be separated on the grounds that they each drain their own catchment area , and are in no direct contact with each other . this differentiation is easy to maintain in the upper reaches of rivers , but becomes less clear in the lower reaches . if rivers drain in flat coastal areas , seasonal floodplains may join several river systems .
along its way to the ocean , rivers take many different forms and shapes , and differences between the various zones of one river are often greater than between homologous zones of different rivers . the landscape as well as the rainfall pattern impose certain characteristics on the rivers . annual water fluctuations in rivers may be very moderate in areas of constant rainfall or constant release of water through the presence of lakes , swamps , heavy forests , or floodplains near their headwaters . floodrivers on the other hand are characterised by extreme annual fluctuations in water level from severe flood to sometimes complete dissipation in the dry season , caused by significant seasonal variations rainfall and poor water retention capacity of the land near the headwaters .
river management and water management in general is aimed at the development of water resources for human use , being urban supplies , irrigation or industrial use . this has in the past led to over - exploitation and unsustainable use of the resource . this has recently been recognised by most stakeholders and there is now a general consensus that for sustainable use of the water , protection of the water resource should prevail over pure development or exploitation . it is also generally recognised that water is but one component of the whole aquatic environment and that protection and management of water must address the integrity and function of aquatic ecosystems . this brings with it the need to address the links between land and water systems through integrated catchment management .
the larger river systems in southern africa are shared between various countries . table 1 presents the shared river systems in southern africa . integrated catchment management demands collaboration between different authorities within one country , but in cases of shared rivers also requires collaboration between different countries .
the approach of integrated catchment management , and ensuring the protection and ecological and environmental integrity of these systems , will lead to a more sustainable use of the water resources . however , this requires a change of the present management , and in the short term reduced access to the resource for some . this change in management will therefore most likely meet resistance from some users . overcoming this resistance will be especially difficult when agreements on implementation have to be made between different countries . effects of certain management decisions may be felt more in one country while the benefits for that same country may be less tangible .
integrated catchment management encompasses many different intermediate objectives , goals and activities . the prevention and control of introduced species in a catchment is only one of the activities to improve the overall management of a river system ( figure 2 ) .
the international convention on biodiversity stated that urgent and decisive action is needed to conserve and maintain genes , species and ecosystems , with a view to the sustainable management and use of biological resources . the introductions of aquatic species are generally seen as an important cause of habitat alteration and have caused a loss of aquatic biological diversity in many places around the world .
prevention of further introductions however does not imply a direct change in the present use of the water resource , and although it may impact on future economic activities in the catchment , it does not change the present utilization . immediate and powerful opposition towards changes in the policy on introductions of aquatic species in a river system should therefore not be expected .
the introduction of an aquatic species is not necessarily a matter of internal affairs but will have a direct impact in other countries sharing the same system , and cross boundary collaboration should be initiated to discuss this issue . the more countries involved in such discussions the more complicated the issue becomes and the less likely a solution will be identified . it was therefore deemed appropriate to start with a river system that is only shared by a few countries , and where countries have identified the need to collaborate on the issue of introductions of aquatic species . the limpopo river system meets these criteria , and it was argued that results for this review can be used as an example for collaboration on this issue for other more complex aquatic systems .
fishes are the most numerous of the vertebrates in the world ; around 50 % of all the vertebrate species are fishes . fish species evolved much earlier than the other vertebrates and thus had more time to develop a wide variety of species . however , the fact that fish live in water is an important aspect for explaining the differences in species and their distribution . the determinants of fish species distribution can be categorized into physical , biological , ecological and human factors .
freshwater systems are usually restricted and well defined . consequently the distribution of freshwater organisms , and particularly fishes , is often more distinct and restricted than that of other animals . the physical boundary of a particular water body is the most obvious limit to fish distribution . fish in one river system are in no direct contact with species in an other river system and can develop independently .
river systems are much less separated from the point of view of fish movements than from the point of view of water movements . river systems are generally separated on the basis of drainage , and although waters from different systems may mix in the coastal floodplains , this connection between different rivers is only seasonal . fish however can use this seasonal and more sporadic contact of waters from different rivers systems to move from one system to the other . from the point of view of fish distribution river systems are therefore much less distinctly separated .
the rivers and lakes do change over time in accordance with geological processes such as mountain building , rifting and erosion . the distribution of the redfin minnows in south africa is explained by such changes in river systems . the species pseudobarbus quathlambae , found in the upper reaches of the orange river in lesotho , is closely related to the pseudobarbus species found in the rivers of the western and southern cape . these rivers , however , clearly belong to a separate river system with no connection to the rivers of the orange basin . this fish distribution can be explained by the fact that the upper reaches of the cape rivers were previously all part of the orange river system . through changes in geology these upper reaches were captured in separate coastal rivers and the species were transferred to these coastal systems .
the distribution of kneria auriculata found in the upland streams of the pungwe , buzi and save in zimbabwe and mozambique as well in the crocodile river of the incomati system in south africa , can be explained by the fact that these rivers were previously part of the limpopo system , but as the river changed its course the species became isolated in two different distinct river systems .
within one river there is typically a succession of types of water course from steep slopes near the source to minimal slope near the mouth . this succession is by no means adhered to , and rivers show several successive reaches of floodplains and rapids along their length . fish species distribution alters with these changes in gradient and water flow . lentic species are only found in stagnant or slow flowing waters while others require fast flowing waters ( i . e . lotic species ) . the depth of the water has also a direct effect on the fish species distribution . larger fish are generally found in deeper waters , smaller ones in the shallows .
certain fish species are adapted to live in seasonal waters ; they either survive dry periods , produce eggs that are adapted to drought and hatch during the next flood , or migrate from permanent waters to the seasonal streams and pools . seasonal streams therefore accommodate fish species different from permanent rivers .
the fact that fish are poikilothermic while water is the medium of their environment , ensures that fish are under a much greater influence of their environment than most terrestrial organisms . the water quality in terms of oxygen content , salinity , hardness , acidity and temperature is of direct influence on the physiological processes of a fish . most fish are able to cope with only a certain range of these water quality parameters , and when these change this is directly reflected by a change in the fish population .
an organism has to find its own place in an environment , where it will be able to compete successfully with other species for food and space , it has to find an environment suitable for reproduction and must be able to avoid predation . fish species have developed specific strategies to cope with their environments . typically these strategies can be characterised as altricial or precocial . species with an altricial life style show a high adaptability towards changes in their environment , use a wide range of feeds , and can be characterised as generalist or invaders . they are found in unstable and unpredictable environments , where mortality is determined by the environmental conditions and not by stock densities . their reproduction is adapted to the unpredictable situation , producing large numbers of consequently small eggs . fish species with a precocial life style can be found in stable environments , and are highly specialised . they live in an environment where the aquatic community has established a stable biological equilibrium . mortality is density dependant and fluctuation in population composition is low . their reproduction strategy is focused on quality instead of quantity . they produce limited numbers of eggs and offspring but produce large eggs and in many cases take care of their offspring .
fish have adapted their strategy to the predictability of the environment , therefore different species communities are found in an environment with minimal fluctuations than in unpredictable environments . in a predictable environment the species diversity is high , these species are very specialised and are sometimes endemic to that particular environment . table 2 gives the differences between populations in a predictable and unpredictable environment .
through manipulation of the environment , human activities have indirectly increased as well as decreased the distribution ranges of fish species . fish communities are adapted to an environment and the populations have established a balance within this environment . activities that change the conditions will have a direct influence on the aquatic communities .
the construction of dams and weirs have obstructed free movements of fish along the rivers , while they have also created new environments . the reservoir environment is suitable for some species while others have disappeared from these new systems . other changes in the catchment and wetlands have altered the environments , favouring some species but with negative effects for many others .
the connection of river systems with the purpose of improving the water supply to areas with water shortages have created a possibility for fish to move from one river system to another , and so expanding the distribution range of the fish .
people have introduced several aquatic species and so directly influenced the distribution of these and other species .
introduced species can be defined as species intentionally or accidentally transported and released by man into an environment outside its natural range .
although there are many different native species of fish in southern africa , a large number of species have also been introduced . introductions have occurred for the purpose of fishing , to increase the production of lakes and rivers , or to improve the sport fishing opportunities . in some instances the creation of new environments has promoted the introduction of species that would occupy the new and vacant niches , like the introduction of limnotrissa miodon into lake kariba .
most introductions have been made for the purpose of aquaculture . the main reason for using introduced species is that the culture techniques of these species are well known and information is available . food producers try to minimise risks by using technologies , including fish species , that are already well established . aquaculture is conducted in controlled systems , but even if these fish are used in strictly confined areas for farming only , there is still a high risk of fish escaping and finding their way to natural waters .
whether or not these introduced species will establish viable populations in natural water depends on many factors . the species has to be adapted to the physical environment but also has to find its ecological niche . the ecological resistance , a system of checks and balances opposing the invasion of a new species into natural ecosystems , is generally lower in unstable and unpredictable environments than it is in stable environments . however , the introduced species still has to be able to cope with this environment , and species with an altricial life style will probably establish themselves more easily than other species .
the ecological resistance of a stable environment is often much higher than that of unpredictable environments . the communities in these environments have a high and complicated species diversity with most niches filled by highly specialised fish species . however , the success of an introduced species to establish itself becomes much greater when the ecology of the systems is disturbed . a disturbance creates threats to many species but at the same time opportunities for others . human activities have an influence on the composition of the species originally present , but may also influence the changes of introduced species to establish viable populations .
this does not mean that introduced species will never get established in stable communities with a high degree of specialisation . the introduction of nile perch , lates niloticus in lake victoria is a striking example of a situation where an introduced species has had a great impact on the extremely diverse cichlid population .
the limpopo system , situated between the 20 and 26 degrees south and 25 and 34 degrees east , drains extensive areas in botswana ( 91500 km 2 ) , south africa ( 183800 km 2 ) , zimbabwe ( 62200 km 2 ) and mozambique ( 92500 km 2 ) . the limpopo river itself forms a lengthly boundary between botswana and south africa and makes up the whole boundary between south africa and zimbabwe . figure 3 shows the river and its main tributaries .
the fish life of the whole limpopo systems has never received the attention it deserves , partly as a result of the political division of the catchment and the fact that most of the limpopo river itself forms international boundaries . as a result of the lack of earlier information on the hydrology as well as biota , recent changes and environmental deterioration have not been recorded .
the total number of recorded species in the limpopo system is 83 , see table 3 . of these 48 species are found in the limpopo river itself , while the others are only recorded in its tributaries . as a result of the relatively short period of isolation from other river systems , and due to the characteristics of the system , the limpopo systems has relatively low endemicity , only three species are restricted in their distribution range to this system .
eighteen introduced fish species have established populations in the limpopo river system , of which six are in the limpopo river itself . there have been various reasons for introducing these fish species , improving the sport fishing opportunities in dams in the catchments has been an important motive . fish have then escaped from these dams and established populations in the river system .
grass carp feed mainly on aquatic vegetation , and are able to consume large quantities of plant material ( e . g . consuming up to their own body weight daily ) if present in high densities , grass carp are able to eradicate submerged plants and will drastically alter the vegetation profiles of the water they inhabit .
legislation and associated regulations concerning the introduction of aquatic species can be enacted at international , regional , bilateral and national levels . legislation is passed by parliament or equivalent fora . it usually enables a person such as the chief fisheries officer to draw up regulations to implement the general laws contained in the legislation . regulations are therefore subsidiary legislation .
an introduced species can be defined as a species that does not naturally occur in the area but has been introduced to it from outside that area . this definition is related to physical boundaries and not political ones . they are therefore not always compatible with those contained in national legislation . words used in national legislation are imported , non - indigenous , native , transferred and introduced . interpretation of these words may vary between countries .
the department of water resources under the ministry of energy and water resource development is responsible for the provision and conservation of water . it has the mandate to control water pollution nation wide and delegates its functions to provincial water engineers and local authorities . the water pollution control section is responsible for the co - ordination of activities by these bodies and for ensuring that a uniform and consistent approach to water pollution is applied throughout the country .
the functions of the department of natural resources ( dnr ) , under the ministry of environment and tourism , are to promote the adoption of objectives or standards relating to environmental quality and pollution control , mitigate any adverse environmental impacts of new projects and provide zimbabweans with information on environmental issues . the dnr has the responsibility to assist other government departments and to work with provincial authorities and the public to conserve and enhance the quality of the environment . dnr emphasises environmental awareness , environmental research , soil conservation , water resource management , forest management and the monitoring of mining activities .
under the same ministry , the department of national parks and wildlife management ( dnpwm ) has legal responsibilities that are limited to state lands . the department has no legal obligations to work in communal lands except where stray indigenous animals represent a threat to human life . the aims of this department are to conserve wildlife and biological diversity and to promote sustainable use of natural resources . the introduction and transfer of fish falls under the responsibility of this department as defined in the national parks and wildlife act of 1975 .
the dnpwm has proposed to use grass carp for weed control in reservoirs around harare . if this species is to be stocked , only triploids will be used in order to prevent the presence of fish that may have the potential to establish breeding populations .
the major responsibility for water in botswana falls under the ministry of mineral resources and water affairs . the ministry and its various departments are responsible for the use of water in aquifers , the distribution of water , the design and construction of water systems , the exploration of water aquifers , the monitoring of water flows the testing and analysis of water , the disposal of waste water , and the establishment of a licensing body for the use of the water .
the ministry of commerce and industry is responsible for the management of water resources within their areas of jurisdiction , i . e . game reserves and parks .
the ministry of agriculture is responsible for the protection and management of watersheds . the fish protection act provides for the making of regulations by the minister of agriculture :
the minister may make regulations which shall apply to such areas as are specified therein , providing for the more effectual control , protection and improvement of fish , and the government and management of any specified area in which fishing may be carried on , and without prejudice to the generality of the foregoing for all or any part of the following purposes . . . .
prohibiting , restricting or regulating the transfer within botswana of any live fish . ”
the department of water affairs is under the ministry of public works and housing and has the responsibility for the management of water resources at a national level . the regional water administrations are organised on the basis of river basins and are responsible for water resource administration in their respective regions .
in 1991 a national water council was created as an intersectoral water development co - ordinating council at ministerial level . it is in charge of the relevant aspects of the general water management policy and assumes responsibility for its compliance .
in 1995 a national water policy was approved . one of the main principles of the policy is the integration of water resource management . it uses the approach that water should be allocated through integrated river basin management in order to optimise the benefits to the community . it also takes into account the environmental impacts and water conservation . the minister of agriculture and fisheries is a member of this council .
mozambique does not have clear regulations concerning the introduction or use of fish . the present legislation dates from 1960 and states that :
these regulations are not adjusted to the present situation in the country , and the country faces problems with over - exploitation , and uncontrolled catching and exporting of ornamental fish , corals , etc . efforts are being made to improve the legislation , for which cross - border collaboration is seriously considered .
mozambique participates in a programme to conserve the biodiversity of lake malawi / niassa . one of the activities under this project is to harmonise the rules regarding introductions of new species and management of the lake between the three countries sharing this system .
the custodianship of the water resource of south africa is the responsibility of the department of water affairs and forestry ( dwaf ) at national level . water is recognised as a precious national asset , to be managed for the public good . management and planning of the water resources at national level are essential given the fact that water resources are very unevenly distributed in relation to centres of population and development . this has made inter - basin water transfers necessary on regional , national and international scales .
the dwaf is responsible for macro - scale planning of water resources development . their task is to reconcile demand with supply on a sustainable basis , to assess possible water supplies , and to draw up proposals for investigating the feasibility of water resource developments .
over the last few years there has been some provision made for “water for the environment” in the planning of water resources . initially the environment was seen as a competing water user , but it is now recognised that aquatic ecosystems actually are the resource base , and the maintenance of their functions and integrity is essential to sustainable utilisation .
the directorate of water quality management , under the dwaf , sets national policy and guidelines for water quality management in south africa . in the past the dwaf has had a limited ability to control land uses which generate nonpoint source pollution . land use , planning , control zoning and management are generally functions of provincial government or of other national government departments . frequently the objectives of these other departments can conflict with the requirements for protection and management of water resources . the new water policy addresses the need for dwaf to collaborate with other government departments to jointly identify the best management practices which will prevent or reduce the impacts of nonpoint sources on water resources .
regulations relating to introductions are dealt with within the nine provinces . these provinces have been operating under the old ordinances but are now autonomous in their regulations and are preparing their own acts under the new governmental system . the national aquatic conservation committee ( nacc ) has been set - up to determine policy for aquatic imports and releases in order to achieve compatibility between the provinces . their policy statement is uniform for all provinces , but the implementation may differ between provinces .
the importation of non - indigenous aquatic species requires approval and a permit from a regional department of nature conservation . problem aquatic animals have been categorised according to their potential impact on the environment and appropriate restrictions and conditions apply to each category . these range from no stocking allowed into the inland waters of south africa , to stocking restricted to “non - sensitive” areas or areas where introduced populations have already become established .
the chinese carp have been categorised under the most severe conditions , while special policy guidelines have been prepared for the introductions of grass carp . the nacc has determined that for grass carp only sterile triploids can be stocked under permit in those waters where no suitable alternative indigenous species or other methods of aquatic weed control is feasible , while all possible measures have to be taken to prevent escapes of the fish into other waters .
the institute for water quality studies under the dwaf has developed the national aquatic ecosystem biomonitoring programme ( naebp ) to improve the monitoring of the environmental conditions in the aquatic ecosystem . it has become apparent that monitoring of the chemical and physical quality of water in isolation were not satisfactory indicators of aquatic ecosystem health or integrity . biomonitoring has revealed that in some instances the habitat and water quality conditions were unimpaired but that the fish as well as invertebrate biotic integrity were seriously affected through the introduction of an exotic species . the relevance of the biomonitoring programme in this respect is that effects of introductions can be better monitored and understood and can be used as a basis to assess the risks that they may hold to other systems . besides the impact of introduced species on biotic integrity , understanding of the effect of the introductions is a definite requirement to distinguish between their impact and the impacts of changes in the water quality and physical habitat .
the international convention on biodiversity was adopted in december 1993 , and is probably the most relevant piece of international legislation . this convention recognises the value of natural and domesticated biological diversity and acknowledges the issue of introduction and transfer of species .
each party … shall establish or maintain means to regulate , manage or control the risks associated with the use and release of living modified organisms resulting from biotechnology … .
( h ) prevent the introduction of , control or eradicate those alien species which threaten ecosystems , habitats or species ” .
“ in respect of areas beyond national jurisdiction and on other matters of mutual interest , for the conservation and sustainable use of biological diversity ” .
the mechanisms of such co - operation have to be worked out by the states concerned .
sadc was set up by treaty in 1980 , and has now 12 member countries . one of the main objectives of the treaty is to ensure that development does not impair the diversity and richness of the region ' s natural resource base and the environment . the treaty provides for the achievement of :


pinnixa faba , known as the pea crab , mantle pea crab or large pea crab , is a pea crab which lives harmlessly within a large edible clam .

this species is a symbiont of tresus capax and tresus nuttallii in its mature stage .

pinnixa faba

leo shapiro set
image of pinnixa faba
as an exemplar on
pinnixa
.
pinnixa faba by lambert m . surhone , mariam t . tennoe , susan f . henssonow
pinnixa faba , likely a male , from the mantle cavity of tresus capax . scale in background = mm
pearce , j . b . 1966a . on pinnixa faba and pinnixa littoralis ( decapoda : pinnotheridae ) symbiotic with the clam , tresus capax ( pelecypoda : maetridae ) . in : barnes , h . ( ed . ) some contemporary studies in marine science . allen unwin ltd . , london . p . 565 - 589 . [ links ]
citation :
mantle pea crabs , pinnixa faba ~ marinebio . org .
marinebio conservation society . web . accessed monday , july 9 , 2018 . < urltoken > . last update : 3 / 27 / 2014 7 : 47 : 00 am ~ contributor ( s ) : marinebio
dowds , r . e . 1978 . distribution and reproduction of four species of pinnixa ( crustacea : brachyura ) in a north carolina estuary . american zoologist 18 : 599 . [ links ]
_ _ _ _ _ _ . 1998b . dispersão de pinnixa patagoniensis no mediolitoral da praia do cassino , rs , brasil . atlântica 20 ( 1 ) : 5 - 21 . [ links ]
mcdermott , j . j . 1981 . biology of the symbiotic crab pinnixa cylindrical ( say ) ( decapoda , pinnotheridae ) . proceedings of the pennsylvania academy of science 55 : 23 - 27 . [ links ]
coelho , p . a . 1997 . revisão do gênero pinnixa white , 1846 , no brasil ( crustacea , decapoda , pinnotheridae ) . trabalhos oceanográficos da universidade federal de pernambuco 25 : 163 - 193 . [ links ]
research pinnixa faba » barcode of life ~ bioone ~ biodiversity heritage library ~ cites ~ cornell macaulay library [ audio / video ] ~ encyclopedia of life ( eol ) ~ esa online journals ~ fishbase ~ florida museum of natural history ichthyology department ~ gbif ~ google scholar ~ itis ~ iucn redlist ( threatened status ) ~ marine species identification portal ~ ncbi ( pubmed , genbank , etc . ) ~ ocean biogeographic information system ~ plos ~ siris ~ tree of life web project ~ unep - wcmc species database ~ worms
t . capax is a host species for the crabs pinnixa faba and p . littoralis . the crabs infest t . capax in pairs of one adult female and one adult male . the females live under the visceral skirt , a fringe of tissue close to a source of food for the crabs . although the crabs cause relatively little damage to t . capax , they do create irritation on its visceral mass and consume food which the clams would otherwise use . because of this , the crabs are considered parasites rather than symbiotes ( pearce 1966 ) .
manning , r . b . & felder , d . l . 1989 . the pinnixa cristata complex in western atlantic , with a descriptions of two new species ( crustacea : decapoda : pinnotheridae ) . smithsonian contributions to zoology 473 : 1 - 26 . [ links ]
at the generic level results confirmed that clypeasterophilus , dissodactylus , fabia , nepinnotheres , and pinnixa are not monophyletic . nineteen species were removed from the genus pinnixa . eleven of them are reassigned to existing genera : p . faba , p . franciscana , p . littoralis , p . schmitti , p . tomentosa , and p . tubicola are placed within the genus scleroplax , whereas p . abbotti , p . arenicola , p . faxoni , p . floridana , and p . vanderhorsti are reassigned to glassella . t _ _ _ n . gen . is erected to receive p . chaetopterana , and taxa in the p . brevipollex – p . rapax complex while j _ _ _ n . gen . was erected to receive members of the p . pearsei – p . sayana complex , p . affinis , and species in the p . californiensis – p . occidentalis complex .
at species level , the molecular data supported observations based on morphology and confirmed the existence of five new pinnotherid species , three in the genus austinixa , one in tumidotheres , and one in pinnixa . two of them , austinixa r _ _ _ and tumidotheres c _ _ _ , were described here .
_ _ _ _ _ _ . 2005 . biology of the brachyuran crab pinnixa chaetopterana stimpson ( decapoda : pinnotheridae ) symbiotic with tubicolous polychaets along the atlantic coast of the united states , with additional notes on other polychaets associations . proceedings of the biological society of washington 118 ( 4 ) : 742 - 764 . [ links ]
alves , e . s . & pezzuto , p . r . 1998a . population dynamics of pinnixa patagoniensis rathbun , 1918 ( brachyura : pinnotheridae ) a symbiotic crab of sergio mirim ( thalassinidea : callianassidae ) in cassino beach , southern brazil . pubblicazioni della stazione zoologica di napoli : marine ecology 19 ( 1 ) : 37 - 51 . [ links ]
this closeup shows the dark eggs bulging out between her abdomen and the underside of her thorax . crabs , hermit crabs , and true shrimp carry their eggs on their abdomens like this , attached to their pleopods . females have featherlike pleopods for attaching the eggs to , while male crabs have only the first few pleopods and use them for copulation . notice also her claw - - the propodus and dactyl sides of the claw are contoured to fit together without a gap , which is characteristic of p . faba .
html public
- / / w3c / / dtd xhtml 1 . 0 strict / / en
urltoken
this site uses cookies . by continuing to browse the site you are agreeing to our use of cookies .
brill’s mybook program is exclusively available on brillonline books and journals . students and scholars affiliated with an institution that has purchased a brill e - book on the brillonline platform automatically have access to the mybook option for the title ( s ) acquired by the library . brill mybook is a print - on - demand paperback copy which is sold at a favorably uniform low price .
< ? xml version =
1 . 0
encoding =
utf - 8
? > < event > < eventlog > < portalid > brill < / portalid > < sessionid > ri - malyafhpf7ypt _ gr8ivoo . x - brill - live - 02 < / sessionid > < useragent > python / 3 . 5 aiohttp / 3 . 3 . 2 < / useragent > < identityid > guest < / identityid > < identity _ list > guest < / identity _ list > < ipaddress > 35 . 239 . 175 . 160 < / ipaddress > < eventtype > personalisation < / eventtype > < createdon > 1531171117022 < / createdon > < / eventlog > < eventlogproperty > < item _ id > urltoken < / item _ id > < type > favourite < / type > < / eventlogproperty > < / event >
html public
- / / w3c / / dtd html 4 . 0 transitional / / en
is a squared oval or nearly circular , and usually wider than long . they are symbionts with worms , ascidians , bivalves , etc .
of the third leg in males is more than twice as long as wide ( see above ) . males are hard - bodied and females are softer . the male has a tooth near the base of the
. color variable , from white to orange . male often has dark markings . male carapace width to 1 . 75 cm , females to 2 . 5 cm .
how to distinguish from similar species : pinnixia littoralis , another common species , has an acute outer margin to its eye orbits and both sexes have a gap between the propodus and dactyl of the claw .
geographical range : prince of wales island , alaska to newport beach , ca . this species is much more common than is p . littoralis in puget sound .
habitat : primarily found within the fat gaper clam tresus capax . juveniles may be in other clam species .
zmarzly , deborah l . , 1992 . taxonomic review of pea crabs in the genus
( decapoda : brachyura : pinnotheridae ) occurring on the california shelf , with descriptions of two species . j . crustacean biology 12 : 4 pp . 677 - 713
general references : jensen , 1995 kozloff , 1993 morris et al . , 1980 niesen , 1997 o ' clair and o ' clair , 1998 ricketts et al . , 1985
there is no rostrum and no teeth between the eyes , and the outer margins of the eye sockets are rounded .
here is another individual , with a bit more setae than the one above . this one is likely a female ( not the same one as below ) , from tresus capa x . photo by dave cowles , july 2008
below is a series of photos of a gravid female from tresus capa x . click on any of them to enlarge them .
from the top , the gravid female looks similar to other individuals . note , however , that the first segment of her abdomen can be seen bulging out at her posterior end ( at the bottom in this picture ) . that is because she is carrying so many eggs that she cannot fold her abdomen anywhere near flat against her underside and must hold it partly extended .
this face - on photo shows the nature of her problem . her abdomen is so full of eggs that she can hardly hold them . when she tries to walk around her abdomen bulges out so far below her that she has to stand on tiptoe in order to barely lift her abdomen off the ground .
note the rounded orbits ( margin of the space around the eyes ) . all photos by dave cowles , july 2008
html public
- / / w3c / / dtd html 4 . 01 transitional / / en
urltoken
mclaughlin et al . 2005 . common and scientific names of aquatic invertebrates from the united states and canada : crustaceans . american fisheries society special publication 31
williams , austin b . , lawrence g . abele , d . l . felder , h . h . hobbs , jr . , r . b . manning , et al .
disclaimer : itis taxonomy is based on the latest scientific consensus available , and is provided as a general reference source for interested parties . however , it is not a legal authority for statutory or regulatory purposes . while every effort has been made to provide the most reliable and up - to - date information available , ultimate legal requirements with respect to species are contained in provisions of treaties to which the united states is a party , wildlife statutes , regulations , and any applicable notices that have been published in the federal register . for further information on u . s . legal requirements with respect to protected taxa , please contact the u . s . fish and wildlife service .
confused by a class within a class or an order within an order ? please see our brief essay .
to cite this page : myers , p . , r . espinosa , c . s . parr , t . jones , g . s . hammond , and t . a . dewey . 2018 . the animal diversity web ( online ) . accessed at https : / / animaldiversity . org .
disclaimer : the animal diversity web is an educational resource written largely by and for college students . adw doesn ' t cover all species in the world , nor does it include all the latest scientific information about organisms we describe . though we edit our accounts for accuracy , we cannot guarantee all information in those accounts . while adw staff and contributors provide references to books and websites that we believe are reputable , we cannot necessarily endorse the contents of references beyond our control .
this material is based upon work supported by the national science foundation grants drl 0089283 , drl 0628151 , due 0633095 , drl 0918590 , and due 1122742 . additional support has come from the marisla foundation , um college of literature , science , and the arts , museum of zoology , and information and technology services .
eol content is automatically assembled from many different content providers . as a result , from time to time you may find pages on eol that are confusing .
to request an improvement , please leave a comment on the page . thank you !
html public
- / / w3c / / dtd html 4 . 01 transitional / / en
javascript is required to use this web site . please turn it on before proceeding .
html public
- / / w3c / / dtd xhtml 1 . 0 transitional / / en
urltoken
this home page section for this species is currently being developed and will be completed asap ! if you would like to help out or know of a great video , photo or site about this species , let us know and we ' ll notify you as soon as it is finished . our current project plan is to have all marine species home pages finished before christmas this year . if you ' d like to find out more about our ongoing projects here at marinebio , check out our marinebio projects page .
start or join a discussion about this species below or send us an email to report any errors or submit suggestions for this page . we greatly appreciate all feedback !
help us protect and restore marine life by supporting our various online community - centered marine conservation projects that are effectively sharing the wonders of the ocean with millions each year around the world , raising a balanced awareness of the increasingly troubling and often very complex marine conservation issues that affect marine life and ourselves directly , providing support to marine conservation groups on the frontlines that are making real differences today , and the scientists , teachers and students involved in the marine life sciences .
with your support , most marine life and their ocean habitats can be protected , if not restored to their former natural levels of biodiversity . we sincerely thank our thousands of members , donors and sponsors , who have decided to get involved and support the marinebio conservation society .
deep music digitally imported urltoken proton radio * radio paradise radiotunes somafm wers 88 . 9 fm
~ sharing the wonders of the ocean to inspire conservation , education , research , and a sea ethic ~ marinebio . org , inc . is a u . s . 501 ( c ) 3 charitable , nonprofit organization . contact : info @ urltoken all marinebio conservation society memberships and donations are tax deductible in the united states . > < ( ( ( ( ° > © 1998 - 2017 marinebio copyright & terms of use . privacy policy . > - < °° > - <
for all at last returns to the sea — to oceanus , the ocean river , like the everflowing stream of time , the beginning and the end .
- rachel carson
this site uses cookies to improve performance . if your browser does not accept cookies , you cannot view this site .
there are many reasons why a cookie could not be set correctly . below are the most common reasons :
you have cookies disabled in your browser . you need to reset your browser to accept cookies or to ask you if you want to accept cookies .
your browser asks you whether you want to accept cookies and you declined . to accept cookies from this site , use the back button and accept the cookie .
your browser does not support cookies . try a different browser if you suspect this .
the date on your computer is in the past . if your computer ' s clock shows a date before 1 jan 1970 , the browser will automatically forget the cookie . to fix this , set the correct time and date on your computer .
you have installed an application that monitors or blocks cookies from being set . you must disable the application while logging in or check with your system administrator .
this site uses cookies to improve performance by remembering that you are logged in when you go from page to page . to provide access without cookies would require the site to create a new session for every page you visit , which slows the system down to an unacceptable level .
this site stores nothing other than an automatically generated session id in the cookie ; no other information is captured .
in general , only the information that you provide , or the choices you make while visiting a web site , can be stored in a cookie . for example , the site cannot determine your email name unless you choose to type it . allowing a website to create a cookie does not give that or any other site access to the rest of your computer , and only the site that created the cookie can read it .
laboratório de bioecologia e sistemática de crustáceos , departamento de biologia , faculdade de filosofia , ciências e letras de ribeirão preto , universidade de são paulo , programa de pós - graduação em biologia comparada , av . bandeirantes , 3900 , 14040 - 901 ribeirão preto , sp , brazil . ( douglaspeiro @ urltoken ; flmantel @ urltoken )
the pinnotheridae family is one of the most diverse and complex groups of brachyuran crabs , many of them symbionts of a wide variety of invertebrates . the present study describes the population dynamics of the pea crab
( say , 1818 ) . individuals ( n = 588 ) were collected bimonthly from may , 2005 to september , 2006 along a sandy beach in the southwestern atlantic , state of são paulo , brazil . our data indicated that the population demography of
was characterized by a bimodal size - frequency distribution ( between 2 . 0 and 4 . 0 mm and between 8 . 0 and 9 . 0 mm cw ) that remained similar throughout the study period . sex ratio does not differ significantly from 1 : 1 ( p > 0 . 05 ) , which confirms the pattern observed in other symbiontic pinnotherids . density values ( 1 . 72 ± 1 . 34 ind .  ap .
) are in agreement with those found for other species of the genus . the mean symbiosis incidence ( 75 . 6 % ) was one of the highest among species of the pinnotheridae family , but it was the lowest among the three studied species of the genus . recruitment pattern was annual , beginning in may and peaking in july , in both years , after the peak of ovigerous females in the population ( from march to may ) . our findings describe ecological and biological aspects of
similar to those of other species of this genus , even from different geographic localities .
pinnotheridae constitui um dos mais diversos e complexos grupos de caranguejos , sendo muitos deles simbiontes de uma grande variedade de invertebrados . o presente estudo descreve a dinâmica populacional do caranguejo pinoterídeo austinixa aidae ( righi , 1967 ) , um simbionte que vive associado às galerias do
corrupto
callichirus major ( say , 1818 ) . os exemplares ( n = 588 ) foram coletados a cada dois meses entre maio de 2005 e setembro de 2006 , em uma praia arenosa no litoral de são paulo , brasil . nossos resultados indicaram que a população de a . aidae foi caracterizada por uma distribuição bimodal em classes de tamanho ( entre 2 , 0 e 4 , 0 mm ( cc : comprimento da carapaça ) e entre 8 , 0 e 9 , 0 mm ( cc ) ) , padrão constante ao longo do período de estudo . a razão sexual não diferiu significativamente de 1 : 1 ( p > 0 , 05 ) , confirmando o padrão observado para outros pinoterídeos simbiontes . os valores de densidade desta espécie ( 1 , 72 ± 1 , 34 indivíduos por toca ) estão de acordo com os estabelecidos para o gênero . a incidência média ( 75 , 6 % ) está entre as mais altas das espécies de pinnotheridae , entretanto é a menor dentre as três espécies do gênero já estudadas . o padrão de recrutamento foi anual ( tendo início em maio e atingindo maior proporção em julho , nos dois anos de estudo ) , e foi registrado após os picos de ocorrência de fêmeas ovígeras na população ( de março a maio ) . nossos resultados confirmam que a . aidae possui padrões ecológicos e biológicos similares aos desenvolvidos pelas espécies do gênero , mesmo em diferentes localidades .
palavras - chave : estrutura populacional , pinoterídeos , região entremarés , simbiose , brasil .
pinnotheridae pea crabs ( brachyura ) are typically small and symbiotic of a wide variety of benthonic invertebrate hosts ( schmitt et al . , 1973 ; williams , 1984 ; harrison & hanley , 2005 ) . they are endo and / or ectosymbionts found associated with bivalves , gastropods , echinoderms , echiurids , brachiopods , balanoglossids and ascidians , and inside polychaets ' tubes and crustacean burrows ( schmitt et al . , 1973 ; manning & morton , 1987 ; campos , 1990 ; harrison & hanley , 2005 ) . moreover , pinnotherid crabs are widely distributed along the marine coastal habitats of almost all oceans ( schmitt et al . , 1973 ; martins & d ' incao , 1996 ) . despite their ecological importance and their great diversity , the information about the population demography of the pea crabs is still scarce , especially about those species that inhabit the atlantic coast of the americas .
samples and procedures . the perequê - açu beach ( ubatuba , northern coast state of são paulo , brazil ; southwestern atlantic ) , is located in the northern extremity of ubatuba bay . this beach is semi - protected and dissipative , composed by fine sand . sampling was conducted bimonthly in the intertidal zone of the beach at daytime and during low tide , from may , 2005 to september , 2006 . it was taken from a plot that was ~ 400 m long by ~ 30 m wide , parallel to the waterline , by the right side of river indaiá ' s mouth ( 23º24 ' 59 ' ' s , 45º03 ' 17 ' ' w ) .
the crustaceans were collected for 2 hours during each sampling visit by two people with a commercial yabby pump ( manning , 1975 ) , used for sampling the c . major galleries . once collected , the specimens were carefully washed with seawater and separated from the sand with a 1 mm mesh sieve and were directly placed into plastic bags , then labeled , frozen , and transported to the laboratory to be analyzed . preliminary attempts permitted us to perfect the protocol above for shrimp and crab collections . we are confident that we were very efficient in capturing all animals from each gallery ( d . f . peiró , j . a . baeza & f . l . mantelatto , unpublished data ) . all material was preserved in ethanol 80 % and deposited in the crustacean collection of the departamento de biologia , faculdade de filosofia , ciências e letras de ribeirão preto , universidade de são paulo , ( ccdb / ffclrp / usp ) under the catalogue # 2102 . in each sampling period , water temperature and salinity were measured before the collection .
the burrows of c . major own only one aperture to the sand surface that varies in shape and has a ~ 5 mm diameter . behind their opening , the burrows resemble a narrow tube that runs perpendicular to the surface up to 20 or 40 cm deep . austinixa aidae inhabits this tubular section of the burrow and not the sections below it ( d . f . peiró , j . a . baeza & f . l . mantelatto , unpublished data ) . from this point below , the diameter of the gallery increases ; it directs to the sides and deepens farther . the length and the diameter of this last section are proportional to the size of the shrimp that constructs the gallery and it attains approximately 1 . 5 m depth and between 10 and 30 mm diameter ( rodrigues & shimizu , 1997 ) .
during sampling , each burrow opening was pumped only twice , since the sediment collapses due to the fine grains of the sand . however , the rapid collapsing of the sediment during the process of pumping does not affect the ability to catch the crabs , given that these crabs only inhabit the narrower upper part of the pumped burrows . importantly , the rapid collapse also eliminates the risk of sampling the same burrow more than once ( alves & pezzuto , 1998a ) . taking into consideration that the galleries of c . major have a single opening to the sand surface ( shimizu & rosso , 2000 ) , the values reported herein refer always to a . aidae per gallery of c . major ( ind .  ap . - 1 ) ( alves & pezzuto , 1998a ) .
three ontogenetic stages were considered : recruits , juveniles and adults . the recruits - defined as those individuals that survived the pelagicbenthic transition and became first crab instars - correspond to the smallest individuals collected , which formed the first size class in the size structure . in essence , recruits are the early juveniles or the young of the year ( pardo et al . , 2007 ) . juveniles were all non identified individuals that displayed undifferentiated or not well - developed pleopods , including the recruits . adults were classified as either males or females according to the analysis of the pleopod . the males have a pair of long and thin modified pleopods on the ventral surface of the first abdominal somite and a pair of short modified pleopods on the second abdominal somite . the females have four pairs of short pleopods from the second to the fifth abdominal somites . the ovigerous females carry an egg mass adhered to the pleopods . the following measurement was performed under a stereomicroscope with the aid of a drawing tube ( 0 . 1 mm precision ) : the maximum carapace width ( cw ) of all crabs retrieved from each gallery was measured . the oval area length ( ol ) of the thalassinidea hosts was measured with a 0 . 02 mm precision caliper .
data analysis . in order to evaluate the correlation between the environmental factors ( water temperature and salinity ) and the abundance of crabs , the pearson ' s product moment correlation was utilized . the normality test ks ( kolmogorov - smirnov ) was used to evaluate the normality of the population according to the size classes ' structure . the number of classes was determined by the sturges ( 1926 ) formula : k = 1 + log 2 n ;
k
is the number of classes and
n
is the size of sample .
the temporal patterns in the mean densities ( number of a . aidae per gallery ) and the incidence ( percent of galleries occupied by a . aidae ) were analyzed . possible relations between densities and mean sizes of crabs and the size of their hosts were checked by the pearson ' s product moment correlation ( alves & pezzuto , 1998a ) . differences from the expected 1 : 1 sex ratio pattern were checked for the total of samples collected and for each sampled month by the χ 2 text ( wenner , 1972 ) .
reproductive periods and recruitment were identified by the proportion of ovigerous females in relation to the total of females ( pinheiro & fransozo , 2002 ) and to the presence of juveniles in the samples ( alves & pezzuto , 1998a ) , respectively . all statistical tests were conducted according to zar ( 1996 ) , adopting the significance level p < 0 . 05 .
population structure . during the studied period , a total of 588 specimens of a . aidae were collected in 455 galleries of c . major ; they were distributed as 247 males ( 42 . 0 % ) , 265 females ( 45 . 1 % ) ( 55 ovigerous : 9 . 4 % ) , and 76 juveniles ( non determined individuals ) ( 12 . 9 % ) ( 13 recruits : 2 . 2 % ) . the total number of individuals collected ranged from 24 ( january , 2006 ) to 121 ( july , 2006 ) ( tab . i ) . no correlation was found between water temperature ( 23 . 9 ± 2 . 3ºc ) , salinity ( 27 . 3 ± 8 . 5 % ) and the total number of collected individuals , just between males , females and juveniles individually ( p > 0 . 05 ) .
the carapace width varied between 2 . 4 and 10 . 1 mm ( mean ± sd = 6 . 13 ± 2 . 24 ) for males , between 2 . 5 and 10 . 5 mm ( 6 . 27 ± 2 . 03 ) for females , and between 1 . 0 and 5 . 2 ( 2 . 46 ± 0 . 68 ) for juveniles . no significant differences in cw between the sexes were detected ( t - test ; - 0 . 56 ; p = 0 . 5791 ) , indicating the absence of sexual dimorphism with respect to this dimension . distribution in size classes was slightly bimodal for the total population ( ks = 0 . 087 ; p < 0 . 05 ) , reflecting a non - normal pattern , except in september , 2005 and 2006 ( ks = 0 . 079 and ks = 0 . 059 ; p > 0 . 200 , respectively ) . were detected two size class peaks , between 2 . 0 4 . 0 mm ( cw ) and between 8 . 0 9 . 0 mm ( cw ) : the first peak mainly represented by juveniles ( 2 . 0 3 . 0 mm ) and females ( 3 . 0 4 . 0 mm ) ; the second by males and females ( 8 . 0 9 . 0 mm ) ( fig . 1 ) .
the maximum number of individuals collected per gallery was 14 crabs . the total mean density was 1 . 72 ± 1 . 34 ind .  ap . - 1 . the lowest mean density was registered in september , 2006 ( 1 . 3 ± 0 . 5 ind .  ap . - 1 ) and the highest in july , 2006 ( 2 . 52 ± 1 . 94 ind .  ap . - 1 ) , with a particularly clear juveniles ' variation ( fig . 2 ) during the sample period . the total mean incidence - percentage of occupation - of crabs in the galleries was 75 . 6 % , with a variation during the sample period ( tab . i ; fig . 3 ) . a significant positive correlation was found between the density ( ind .  ap . - 1 ) of a . aidae and the size ( ol ) of their respective hosts c . major ( r = 0 . 501 ; p < 0 . 05 ; n = 73 ) , i . e . the larger the hosts , the higher the number of symbiotic crabs in their burrows . on the other hand , no correlation was found between the size of crabs and the size of their respective hosts ( ol ) ( r = 0 . 037 ; p > 0 . 05 ) .
the highest incidence of juveniles followed the months with a higher density of ovigerous females in the population ( figs 2 , 3 ) . it started in may and reached a higher proportion in july , in both years . males and females did not present great peaks of density , the males ' ranging from 0 . 50 to 1 . 13 ind .  ap . - 1 ( 0 . 73 ± 0 . 20 ind .  ap . - 1 ) , and the females ' from 0 . 58 to 0 . 97 ind .  ap . - 1 ( 0 . 77 ± 0 . 14 ind .  ap . - 1 ) . regarding the males , the tendency of density increase occurred in november , 2005 , four months after the recruitment of juveniles ; and the second in july , 2006 , subsequent bimonthly to the coming of the juveniles to the population . regarding the females , four light tendencies of density increase ( july and november , 2005 , and march and july , 2006 ) occurred . males and females presented a higher mean of incidence ( 54 . 5 ± 18 . 4 % and 57 . 7 ± 14 . 9 % , respectively ) than the juveniles ( 17 . 8 ± 20 . 2 % ) ; however the percentages of occupation vary correspondently during the sample period . the values of juvenile density fluctuated from 0 to 0 . 64 ind .  ap . - 1 ( 0 . 23 ± 0 . 24 ind .  ap . - 1 ) .
the total sex ratio was 0 . 93 : 1 in favor of females , which does not differ significantly from 1 : 1 ( χ 2 = 0 . 57 ; p > 0 . 05 ) . the same pattern was obtained each month . in almost all size classes ( 7 ) the ratios do not differ significantly from 1 : 1 ( p > 0 . 05 ) , except in classes between 2 . 0 3 . 0 mm and 9 . 0 10 . 0 , where males predominate ( 2 . 8 : 1 and 2 . 4 : 1 , respectively ) ; and between 7 . 0 8 . 0 mm , where females predominate ( 0 . 5 : 1 ) ( fig . 4 ) .
reproductive period and recruitment . the percentage of ovigerous females in relation to the total of females was 20 . 8 % ; the frequency varies from 0 ( july , 2005 ) to 50 % ( may , 2005 ) among the samples ( tab . i ; fig . 5 ) . the ovigerous females occurred in almost all sample months , except in july , 2005 . seasonal increases in frequency and abundance of this group were identified , with expressive peaks in 2005 ( may and november : 50 . 0 and 41 . 2 % , respectively ) , and in 2006 ( between march and may : 31 . 6 and 29 . 6 % , respectively ) . due to the presence of ovigerous females throughout the year and the seasonal peaks , the reproductive period was characterized as seasonal continuous . this reproduction system can supply a constant larval input reflecting in continuous recruitment , but not observed in this study . it is important to point out in our study that the recruits were identified only in the months subsequent to the peaks of ovigerous females . the recruitment starts in may and attains major proportion in july , in both years , and it contributes to increase the abundance in the subsequent size classes in the subsequent sample months ( figs 6 , 7 ) .
the juveniles were present in almost all samples , except in march , 2006 , with seasonal abundance increases . the peaks of juveniles occur in may and july , in both years , in the months subsequent to the ovigerous females ' peaks ( fig . 8 ) ( remembering that the recruits are included in this classification ) . an exception occurred thereafter november , 2005 ovigerous female peak ( the month with higher incidence ) , but subsequent months there are not a peak of juveniles .
the size classes ' distribution of juveniles ( figs 6 , 7 ) corroborated the same pattern identified by density ( fig . 2 ) and incidence ( fig . 3 ) analyses , with the seasonal continuous reproduction and the input of juveniles occurring throughout the year . two courts were also identified in some sampled periods ( figs 6 , 7 ) .
in some studies with pinnotheridae - due to its typical symbiotic relationship - the main variables were expressed in number of individuals per host , per pipe aperture or per hosts ' gallery aperture ( mcdermott , 1981 ; alves & pezzuto , 1998a ; mcdermott , 2006 ) . comparing our results with other austinixa species , the number of host gallery apertures is a differential factor to be considered , once they vary among the callianassidae members ( tab . ii ) .
the analysis between the density of a . aidae and the size of their respective host shows a positive correlation , as opposed to what was found in p . patagoniensis when associated with sergio mirim ( alves & pezzuto , 1998a ) . this result grants a peculiar characteristic to a . aidae in the family . the positive correlation is more frequently observed among crabs that are symbiotic of bivalves or polychaets tubes , where the free space in the shell is limited ( gray , 1961 ; pearce , 1966a , 1966b ; jones , 1977 ; bierbaum & ferson , 1986 ) .
the sex ratio did not differ significantly from the pattern proposed by fischer ( 1930 ) , where the natural selection supports an equal proportion for both sexes . in most of the sampled months , the sex ratio was in favor of females , yet not significantly different from 1 : 1 ( p < 0 . 05 ) . when a ratio variation occurs , it can be explained by mortality , habitat preferences and alimentary restrictions acting intensively on one sex ( turra & leite , 2000 ) ; however , these factors do not evaluated here . in addition , the previous hypothesis that suggested that adult crabs featured a mating system other than monogamy in the studied species ( d . f . peiró , j . a . baeza & f . l . mantelatto , unpublished data ) should be considered an explanation for the pattern of the sex ratio observed here .
it was not possible to apply any classification proposed by wenner ( 1972 ) to the sex ratio pattern in this population . no significant differences between the male - female ratios in the majority of size classes were found ; however , there were significant differences in the 2 nd and the 9 th size classes in favor of males and in the 7 th in favor of females . this probably brings us to a new classification that has been registered here for this group of symbiont and that we named
near pattern
. this classification is close to the
pattern
proposed by wenner ( 1972 ) , in which there are no differences in the male / female proportion in most size classes , but allows some few significant differences between the sexes , in favor of males in the final size classes .
acknowledgments . this study was part of a master ' s degree by dfp and was supported by a capes fellowship . flm and dfp are grateful to cnpq for the research and doctor degree fellowships , respectively . part of this study was supported by a funding from cnpq ( grants 471794 / 2006 - 6 and 473050 / 2007 - 2 ) to flm . special thanks to all members of the laboratory of bioecology and crustacean systematics from ffclrp / usp for their help during the field and laboratory work . special thanks go also to emerson mossolin , paulo pezzuto , patricio hernáez and anonymous reviewers for their suggestions and contributions toward the improvement of this paper and julia hetem for revision of the english . the supports of the postgraduate program in comparative biology of ffclrp / usp and of the centro de biologia marinha ( cebimar / usp ) during the collections are also acknowledged . all experiments conducted in this study complied with the current applicable state and federal laws of brazil .
_ _ _ _ _ _ . 1999 . crescimento relativo de austinixa patagoniensis ( rathbun , 1918 ) ( decapoda : pinnotheridae ) , simbionte de sergio mirim ( rodrigues , 1971 ) ( decapoda : callianassidae ) na praia do cassino , rs . nauplius 7 ( 1 ) : 83 - 92 . [ links ]
alves , e . s . & rodrigues , s . a . 2003 . distributional patterns of austinixa patagoniensis ( rathbun , 1918 ) ( decapoda : pinnotheridae ) , a symbiotic crab of callichirus major ( decapoda : callianassidae ) in balneário camboriú beach , santa catarina , brazil . journal of coastal research 35 : 408 - 417 . [ links ]
alves , e . s . ; rodrigues , s . a . & pezzuto , p . r . 2005 . estudo do crescimento relativo de austinixa patagoniensis ( rathbun ) ( decapoda , pinnotheridae ) simbionte de callichirus major ( say ) ( decapoda , callianassidae ) no mesolitoral da praia de balneário camboriú , santa catarina , brasil . revista brasileira de zoologia 22 ( 3 ) : 784 - 792 . [ links ]
asakura , a . & kikuchi , t . 1984 . population ecology of the sand dwelling hermit crab , diogenes nitidimanus terao . 2 . migration and life history . publications from the amakusa marine biological laboratory 7 ( 2 ) : 109 - 123 . [ links ]
ayres - peres , l . & mantelatto , f . l . 2008 . patterns of distribution of the hermit crab loxopagurus loxochelis ( moreira , 1901 ) ( decapoda , diogenidae ) in two coastal areas of southern brazil . revista de biología marina y oceanografía 43 ( 2 ) : 399 - 411 . [ links ]
bierbaum , r . m . & ferson , s . 1986 . do symbiotic pea crabs decrease growth rate in mussels ? the biological bulletin 170 ( 1 ) : 51 - 61 . [ links ]
campos , e . 1990 . calyptraeotheres , a new genus of pinnotheridae for the limpet crab fabia granti glassell , 1933 ( crustacea , brachyura ) . proceedings of the biological society of washington 103 ( 2 ) : 364 - 371 . [ links ]
costa , t . m . & negreiros - fransozo , m . l . 1998 . the reproductive cycle of callinectes danae smith , 1869 ( decapoda , portunidae ) in the ubatuba region , brazil . crustaceana 71 ( 6 ) : 615 - 627 . [ links ]
díaz , h . & conde , j . e . 1989 . population dynamics and life history of the mangrove crab aratus pisonii ( brachyura , grapsidae ) in a marine environment . bulletin of marine science 45 ( 1 ) : 148 - 163 . [ links ]
fischer , r . a . 1930 . the genetical theory of natural selection . 2 . ed . new york , dover . 291p . [ links ]
gray , i . e . 1961 . changes in abundance of the commensal crabs of chaetopeterus . the biological bulletin 120 ( 3 ) : 353 - 359 . [ links ]
harrison , j . s . 2004 . evolution , biogeography , and the utility of mitochondrial 16s and coi genes in phylogenetic analysis of the grab genus austinixa ( decapoda : pinnotheridae ) . molecular phylogenetics and evolution 30 ( 3 ) : 743 - 754 . [ links ]
harrison , j . s . & hanley , p . w . 2005 . austinixa aidae righi , 1967 and a . hardyi heard and manning , 1997 ( decapoda : brachyura : pinnotheridae ) synonymized , with comments on molecular and morphometric methods in crustacean taxonomy . journal of natural history 39 ( 42 ) : 3649 - 3662 . [ links ]
heard , r . w . & manning , r . b . 1997 . austinixa , a new genus of pinnotherid crab ( crustacea : decapoda : brachyura ) , with the description of a . hardyi , a new species from tobago , west indies . proceedings of the biological society of washington 110 ( 3 ) : 393 - 398 . [ links ]
jones , j . b . 1977 . natural history of the pea crab in wellington harbour , new zealand . new zealand journal of marine and freshwater research 11 ( 4 ) : 667 - 676 . [ links ]
manning , r . b . 1975 . two methods for collecting decapods in shallow water . crustaceana 29 : 317 - 319 . [ links ]
manning , r . b . & morton , b . 1987 . pinnotherids ( crustacea : decapoda ) and leptonaceans ( mollusca : bivalvia ) associated with sipunculan worms in hong kong . proceedings of the biological society of washington 100 ( 3 ) : 543 - 551 . [ links ]
mantelatto , f . l . & cuesta , j . a . 2010 . morphology of the first zoeal stage of the commensal southwestern atlantic crab austinixia aidae ( righi , 1967 ) ( brachyura : pinnotheridae ) , hatched in the laboratory . helgoland marine research 64 ( 4 ) : 343 - 348 . [ links ]
mantelatto , f . l . & fransozo , a . 1999 . reproductive biology and moulting cycle of the crab callinectes ornatus ( decapoda , portunidae ) from the ubatuba region , são paulo , brazil . crustaceana 72 ( 1 ) : 63 - 76 . [ links ]
mantelatto , f . l . & sousa , l . m . 2000 . population biology of the hermit crab paguristes tortugae schmitt , 1933 ( anomura , diogenidae ) from anchieta island , ubatuba , brazil . nauplius 8 ( 2 ) : 185 - 193 . [ links ]
martins , s . t . s . & d ' incao , f . 1996 . os pinnotheridae de santa catarina e rio grande do sul , brasil ( decapoda , brachyura ) . revista brasileira de zoologia 13 ( 1 ) : 1 - 26 . [ links ]
_ _ _ _ _ _ . 2006 . the biology of austinixa gorei ( manning & felder , 1989 ) ( decapoda , brachyura , pinnotheridae ) symbiotic in the burrows of intertidal ghost shrimp ( decapoda , thalassinidea , callianassidae ) in miami , florida . crustaceana 79 ( 3 ) : 345 - 361 . [ links ]
melo , g . a . s . 1996 . manual de identificação dos brachyura ( caranguejos e siris ) do litoral brasileiro . são paulo , plêiade / fapesp . 604p . [ links ]
miranda , i . & mantelatto , f . l . 2009 . estimating population features of the anomuran crab petrolisthes armatus ( porcellanidae ) in a remaining and impacted mangrove area of the western atlantic . journal of natural history 43 ( 33 - 34 ) : 2027 - 2039 . [ links ]
ng , p . k . l . ; guinot , d . & davie , p . j . f . 2008 . systema brachyurorum : part 1 . an annotated checklist of extant brachyuran crabs of the world . the raffles bulletin of zoology 17 : 1 - 286 . [ links ]
palacios - theil , e . ; cuesta , j . a . ; campos , e . & felder , d . l . 2009 . molecular genetic re - examination of subfamilies and polyphyly in the family pinnotheridae ( crustacea : decapoda ) . in : martin , j . w . ; crandall , k . a . & felder , d . l . eds . crustacean issues : decapod crustacean phylogenetics . boca raton , taylor & francis / crc . p . 423 - 442 . [ links ]
pardo , l . m . ; piraud , f . ; mantelatto , f . l . & ojeda , f . p . 2007 . ontogenetic pattern of resource use by the tiny hermit crab pagurus villosus ( paguridae ) from the temperate chilean coast . journal of experimental marine biology and ecology 353 ( 1 ) : 68 - 79 . [ links ]
_ _ _ _ _ _ . 1966b . the biology of the mussel crab , fabia subquadrata , from the waters of san juan archipelago , washington . pacific science 20 : 3 - 35 . [ links ]
pinheiro , m . a . a . & fransozo a . 2002 . reproduction of the speckled swimming crab arenaeus cribrarius ( brachyura : portunidae ) on the brazilian coast near 23º302 s . journal of crustacean biology 22 ( 2 ) : 416 - 428 . [ links ]
pinheiro , m . a . a . & terceiro , o . s . l . 2000 . fecundity and reproductive output of the speckled swimming crab arenaeus cribrarius ( lamarck , 1818 ) ( brachyura , portunidae ) . crustaceana 73 ( 9 ) : 1121 - 1137 . [ links ]
rodrigues , s . a . & shimizu , r . m . 1997 . autoecologia de callichirus major ( say , 1818 ) . oecologia brasiliensis 3 ( 1 ) : 155 - 170 . [ links ]
santos , s . & negreiros - fransozo , m . l . 1999 . reproductive cycle of the swimming crab portunus spinimanus latreille , 1819 ( crustacea , decapoda , brachyura ) from ubatuba , são paulo , brazil . revista brasileira de zoologia 16 ( 4 ) : 1183 - 1193 . [ links ]
sastry , a . n . 1983 . ecological aspects of reproduction . in : vernberg , f . j . & vernberg , w . b . eds . the biology of crustacea viii : environmental adaptations . new york , academic . p . 179 - 270 . [ links ]
schmitt , w . l . ; mccain j . c . & davidson , e . s . 1973 . decapoda i . brachyura i . family pinnotheridae . in : gruner , h . e . & holthuis l . b . eds . crustaceorum catalogus . the hague , w . junk . v . 3 , p . 32 - 37 . [ links ]
shimizu , r . m . & rosso , s . 2000 . influence of an oil spill on the abundance of callichirus major ( say , 1818 ) on a sand beach in southeastern brazil ( crustacea : decapoda : thalassinidea ) . nauplius 8 ( 1 ) : 63 - 72 . [ links ]
souza , j . r . b . & borzone , c . a . 2003 . a extração do corrupto , callichirus major ( say ) ( crustacea , thalassinidea ) , para uso como isca em praias do litoral do paraná : as populações exploradas . revista brasileira de zoologia 20 ( 4 ) : 625 - 630 . [ links ]
souza , j . r . b . & gianuca , n . m . 1995 . zonation and seasonal variation of the intertidal macrofauna on a sandy beach of parana state , brazil . scientia marina 59 ( 2 ) : 103 - 111 . [ links ]
sturges , h . a . 1926 . the choice of a class interval . journal of the american statistical association 21 : 65 - 66 . [ links ]
turra , a . & leite , f . p . p . 2000 . population biology and growth of three sympatric species of intertidal hermit crab in south - eastern brazil . journal of the marine biological association of united kingdom 80 ( 6 ) : 1061 - 1069 . [ links ]
warner , g . f . 1977 . the biology of crabs . london , elek science . 202p . [ links ]
wenner , a . m . 1972 . sex ratio as a function of size in marine crustacea . the american naturalist 106 ( 949 ) : 321 - 350 . [ links ]
williams , a . b . 1984 . shrimps , lobsters and crabs of the atlantic coast of the eastern united states , maine to florida . washington , smithsonian institution . 550p . [ links ]
zar , j . h . 1996 . biostatistical analysis . new jersey , prentice - hall . 907p . [ links ]
museu de ciências naturais fundação zoobotânica do rio grande do sul rua dr . salvador frança , 1427 , jardim botânico 90690 - 000 - porto alegre - rs - brasil tel . : + 55 51 - 3320 - 2039 iheringia - zoo @ urltoken
html public
- / / w3c / / dtd html 4 . 01 transitional / / en
urltoken
with pqdt open , you can read the full text of open access dissertations and theses free of charge . about pqdt open search
here the evolutionary history of the group was studied using molecular markers and comparisons to morphological observations . the resulting phylogenies indicated that the species parapinnixa cortesi , parapinnixa hendersoni , pinnotherelia laevigata , sakaina yokoyai , tetrias fischerii , and tetrias scabripes must be removed from the family pinnotheridae . after removing the monotypic genus pinnotherelia , type of the subfamily pinnothereliinae , remaining species of the former subfamily were assigned to pinnixinae , a new subfamily based upon revision and elevation of rank for the tribe pinnixini števčić , 2005 . in addition , the subfamily p _ _ _ , was proposed to accommodate species that were excluded from the other two subfamilies .
bauer , raymond t . , cuesta , jose a . , france , scott c . , neigel , joseph e .
copyright in each dissertation and thesis is retained by the author . all rights reserved
the supplemental file or files you are about to download were provided to proquest by the author as part of a dissertation or thesis . the supplemental files are provided
as is
without warranty . proquest is not responsible for the content , format or impact on the supplemental file ( s ) on our system . in some cases , the file type may be unknown or may be a . exe file . we recommend caution as you open such files .
copyright of the original materials contained in the supplemental file is retained by the author and your access to the supplemental files is subject to the proquest terms and conditions of use .
depending on the size of the file ( s ) you are downloading , the system may take some time to download them . please be patient .
full reference : j . s . h . collins . 2003 . systematic palaeontology , in miocene and pleistocene crabs ( crustacea , decapoda ) from sabah and sarawak . journal of systematic palaeontology 1 : 187 - 226
growth rings may be prominent , especially in the northern parts of its range , as this species nearly ceases feeding in winter . yearly growth lines are much less prominent farther south , but tidal cycle growth lines can often be seen . mantle margin has tiny tentacles with tiny eyes . pumps 2 . 51 liters of water per hour per gram body weight . predators include
- - rapidly extending its foot and jumping away ( movie ) . may be a source of paralytic shellfish poisoning ( psp ) for humans . a simultaneous hermaphrodite . in puget sound they mature in their second year and spawn in july and august . live 15 - 19 years in alaska . may contain small pea crabs such as
bering sea to san diego , ca ; japan ; very common in rosario area .
how to distinguish from similar species : other cockles in the area have an area in the posterior quarter that has prominent concentric ridges as well as radial ribs , or are wider than high ; and do not get larger than about 4 cm . the littleneck clam protothaca staminea has much less prominent radial ribs and the ventral margin does not undulate .