the grass goby ( zosterisessor ophiocephalus ) is a species of goby native to the mediterranean sea , the sea of azov and the black sea .

it is currently the only known member of its genus .

grass goby

reproductive cycle and life history traits of the grass goby , zosterisessor ophiocephalus ( gobiidae ) . . .
age and growth of the grass goby zosterisessor ophiocephalus pallas , 1811 in the gulf of gabes ( tuni . . .
scaggiante m , mazzoldi c , petersen cw , rasotto mb ( 1999 ) . sperm competition and mode of fertilization in the grass goby
mazzoldi c , scaggiante m , ambrosin e , rasotto mb ( 2000 ) . mating system and alternative male mating tactics in the grass goby
ota d , marchesan m , ferrero ea ( 1996 ) sperm release behavior and fertilization in the grass goby . j fish biol 49 : 246–256
in the marbled and grass gobies ) we can consider it as an occasional infestation .
a list is presented of metazoan parasites that infect seven gobiid fishes ( the toad goby mesogobius batrachocephalus , monkey goby neogobius fluviatilis , racer goby n . gymnotrachelus , bighead goby n . kessleri , round goby n . melanostomus , ratan goby n . ratan , and syrman goby n . syrman ) from the dniester estuary ( black sea ) . infections by thirteen species of metazoa parasites , including four . . . [ show full abstract ]
marbled goby was rather rare ( 5 , 7 and 8 fishes respectively ) .
. mode of sexual selection determined by resource abundance in two sand goby populations .
. parental behaviour in relation to the occurrence of sneaking in the common goby .
co - immigration of the marbled goby and its specific parasites to the black sea .
pujolar jm , locatello l , zane l , mazzoldi c ( 2012 ) . body size correlates with fertilization success but not gonad size in grass goby territorial males . plos one 7 ( 10 ) , 46711 .
fauna of this goby . so , the core species in the parasite component community are most -
marbled goby is annual small - sized fish ) was completed . it was a cause of successful
. the influence of oxygen stress on female choice for male nest structure in the common goby .
experiments were performed from 24 april to 23 may 2002 for the grass goby and from 4 july to 7 august for the black goby . aquaria used for the experiments ( 60 × 36 × 40 cm high , 70 l ) were divided in two equal sections by a glass partition , attached to the bottom and sides with silicone , to prevent water and sperm flow across sections ( figure 1 ) . every aquarium was provided with a sandy bottom , water temperature was kept at 16°c for grass goby and 22°c for black goby , and water was renewed daily . the artificial light regimen followed natural conditions , and fish were fed once a day with fresh black mussel meat .
skolbekken r , utne - palm ac ( 2001 ) . parental investment of male two - spotted goby
reproductive biology of the rock goby , gobius paganellus ( actinopterygii : perciformes : gobiidae ) , on . . .
size distribution of male and female two - spotted goby in early ( may ) and late ( july ) reproductive season .
magnhagen c ( 1998 ) . alternative reproductive tactic and courtship in the common goby . j fish biol 53 : 130–137 .
actually , it ' s more like eat and be eaten for most organisms . while plants and some bacteria can make their own food , other organisms must eat living things to survive . this makes them predators . you might not think of a grass - munching cow as much of a predator , but cows are indeed the predators of their grass prey .
feeding habits of the black goby , gobius niger ( linnaeus , 1758 ) , in the gulf of gabes ( southern tuni . . .
similar to the ones of other gobiid species in the black sea , is typical for the marbled goby ( kvach , 2005 a ) .
immler s , mazzoldi c , rasotto mb ( 2004 ) . from sneaker to parental male : change of reproductive traits in the black goby ,
forsgren e , kvarnemo c , lindström k ( 1996 ) . mode of sexual selection determined by resource abundance in two sand goby populations . evolution 50 : 646–654 .
) . this result basically implies a change in mating tactic among the smaller males . the sperm seen in the sdgs of small and intermediate sized males in the late breeding season could be sperm left over from a time when the sdgs functioned primarily for sperm storage ( an earlier sneaking period ) , or that the sdgs continue to be used as sperm storage as well as mucin producers . the grass goby ,
[ … ] in biology makes sense ! , amy dapper writes about one consequence of sex , among grass gobies : “sneaker” males with specialized sperm . and jeremy yoder ( yours truly ) takes a look at daisies that attract pollinators by fooling them [ … ]
as an added bonus , i ( bravely ) searched youtube for videos of goby mating behavior and found this lovely video of a pair of trimma gobies , set to adele’s crazy for you .
of course , the cows themselves are prey to other animals , like humans and coyotes . now we have a simple food chain , with grass plants making food at the bottom , cows as middle predators , and then humans and coyotes as
top predators .
mobley kb , amundsen t , forsgren e , svensson pa , jones ag ( 2009 ) . multiple mating and a low incidence of cuckoldry for nest - holding males in the two - spotted goby ,
. sexual selection and sex roles in the sand goby . in : behaviour and conservation of littoral fishes ( almada vc , oliveira rf , gonçalves ej , eds ) . lisboa : ispa ; 249–274 .
benthic , inshore , brackish water , estuaries and lagoons , on mud and eel - grass meadows . commercial in the black sea and in sivash ( ref . 2058 ) . occasionally recorded in freshwater , but there are no documented records of actual occurrence in european freshwaters ( ref . 59043 ) .
the researchers , part of the rasotta lab group at the university of padova , studied the mating behavior and sperm competition strategies of the grass gobies that inhabit the venetian lagoon . grass gobies exhibit alternative mating strategies . the larger males directly compete for access to , and guard , female mates . in contrast , less competitive males avoid direct competition and instead sneak copulations with females already guarded by other males . this variation in behavioral strategies allowed locatello et al . to ask whether guarding and sneaking males may also employ alternative sperm competition strategies . they hypothesized that the two types of males may differ in the degree to which they invest in high quality seminal fluid or high quality sperm .
citation : utne - palm ac , eduard k , jensen kh , mayer i , jakobsen pj ( 2015 ) size dependent male reproductive tactic in the two - spotted goby ( gobiusculus flavescens ) . plos one 10 ( 12 ) : e0143487 . urltoken
territorial males spent more time patrolling the territory ( time out of the nest ) when one and four sneakers were present rather than in the absence of sneakers ( table 1 , figure 2a ) . attacks ( rapid movements toward the sneaker compartment ) were observed only when sneakers were present ( table 1 , figure 3a ) . considering only the trials in which sneakers were present , territorial males performed more attacks when there were four sneakers compared to a single sneaker in the black goby ( f 1 , 20 = 6 . 12 , p = . 022 ) but not in the grass goby ( f 1 , 11 = 0 . 21 , p = . 66 ) . after the female was introduced , territorial males decreased the time spent patrolling the territory and attacking the sneakers , and male territorial behavior did not differ according to the number of sneakers ( table 1 , figures 2b and 3b ) .
to test how territorial males respond to the presence of sneakers , we measured the behavior and sperm output of territorial males facing different levels of sperm competition in the grass and black gobies . our aim was to investigate whether territorial males adjust their sperm output to the number of sneaker males attending the spawn and to test whether they respond to the presence of sneakers by increasing their mate guarding and courtship rate .
] . ontogeny could to some extent explain why we find predominantly small sized , presumably younger males ( born late in season ) , with sneaker type gonads early in the breeding season , but which develop a more dominant gonad structure with older age later in the season . in a laboratory study on the black goby (
in the two - spotted goby , nest defence , brood care and courtship are energetically demanding [ 22 ] , which probably causes increasing mortality rates of nest holding males over the season . thus one should expect to find smaller males using a sneaking strategy , especially early in the breeding season when male—male competition is at its highest .
] the two - spotted goby exhibits sexual size dimorphism , where males are on average larger than females . however , in the presented studied population on the west norwegian coast ( bergen ) this size dimorphism is reversed as average female size is slightly larger than average male size , caused by a large proportion of very small males (
the results of the experiments demonstrated that , while both ‘guard’ and ‘sneaker’ sperm performed equally well in seminal fluid from males with the same behavioral strategy , the sperm of sneaker males had increased performance in the seminal fluid of guarding males . conversely , the sperm of guarding males had reduced preformance in the seminal fluid of sneaking males . furthermore , when sperm was exposed to a mixture of seminal fluid from both types of males , the sperm of ‘sneaker’ males again outperformed that of ‘guard’ males . all together , these results indicate that grass goby males also exhibit alternative sperm competition strategies , such that ‘guard’ males invest in higher quality seminal fluid at the expense of sperm quality ( measured by swimming speed ) and that ‘sneaker’ males invest in higher quality sperm at the expense of seminal fluid quality .
] . however , the authors of this study speculate that the tendency to observe fewer small colourless males late in the breeding season could be because these smaller males have changed mating tactics , from sneaker to the more colourful territorial males . also the presented findings somewhat contradict a study of cuckoldry reported in a two - spotted goby population on the west coast of sweden [
the diet of the black goby , gobius niger in the gulf of gabes ( southern tunisia ) was described from analysis of stomach contents of 1055 specimens . samples were collected monthly by trawls from february 2009 to january 2010 . in the laboratory , the total length ( tl ) was measured and prey items in the stomach contents were identified to large taxonomic groups . overall , 654 stomachs were empty . . . [ show full abstract ]
three different sampling locations on the west coast of norway were selected in order to obtain samples as representative as possible of the habitat of the two - spotted goby . these locations were the inner and outer fanafjord and the kvalen raunefjord , all located north of bergen , which differed in terms of exposure , temperature and salinity . fish used in the histological studies where captured by beach seine in may and july 2008 at the kvalen raunefjord location .
gobies are the most diverse fish family on the reef , with more than 200 species described . with their generally small sizes and ability to adapt to a wide variety of specialized habitats , gobies have become the most diverse marine fish family in the world . this does not mean they are always successful at avoiding predators , though . for instance , the blueband goby ( valenciennia strigata ) is eaten by a variety of predators , including the venomous coneshell .
coneshells ( conus spp . ) are gastropod mollusks , closely related to the more familiar and harmless land snails . with beautiful , ornately designed shells , coneshells are highly sought - after by shell collectors . these gastropods have evolved as deadly predators , however ; a single puncture from their venomous radula ( modified tooth ) can rapidly paralyze and even kill a human . of course , coneshells evolved not to defend themselves against collectors , but to efficiently kill prey , such as the blueband goby .
the rock goby gobius paganellus is one of the most common gobiid fish on the southern tunisian coast and this study provides the first detailed information on its reproductive biology in the gulf of gabes . a total of 356 males ( 8 . 9 - 14 cm total length , tl ) and 273 females ( 9 . 1 - 14 . 3 cm tl ) were analyzed . specimens were dissected and their gonads and livers were removed . mean size at sexual . . . [ show full abstract ]
] ) , females now resort to courting smaller males ( several females were seen courting small males in the late breeding season ( july ) , while early in the breeding season ( may ) we only observed males courting females . pers . obs . a . c . utne - palm and m . hordnes during a transect snorkeling survey at the same study sites , 2008 ) . in contrast , such a size related tactic change over the breeding season was not found in the sand goby (
grass gobies are external fertilizers , meaning that both sexes release their gametes into the aquatic environment where fertilization takes place . this characteristic allowed the researchers to separate sperm and seminal fluid and set up a reciprocal experimental design in which sperm performance is tested in different seminal fluid environments ( table 1 ) . using this design , they tested sperm performance ( swimming speed ) in the presence of a single type of seminal fluid from either males with the same or different mating strategies . they also performed a second experiment in which sperm from either ‘guard’ or ‘sneaker’ males was exposed to a mixture of seminal fluid from both type of males , which more closely mimics the environment of competing sperm .
in birds , traits associated with good genes and those associated with paternal care are not necessarily the same ( møller and jennions , 2001 ; soler et al . , 1998a ) . in the sand goby , females do not invite sneaker males to sneak ( svensson , 2004 ) , and they probably have no control over parasitic fertilizations . therefore , in contrast to many birds , indirect benefits such as good genes or genetic compatibility have to be provided by the same individual as the direct benefits . this abolishes the potential intersexual conflict between females and nest - holding males over simultaneous parasitic spawnings .
male behaviors used in the statistical analyses are the time the males spent ( 1 ) completely inside the nest , ( 2 ) with head visible in nest opening , ( 3 ) outside the nest , ( 4 ) fanning ( with head visible in nest opening ) , and ( 5 ) displaying toward female ( outside the nest ) ; as well as the number of bouts the males performed ( 6 ) nest building from the inside of the nest , ( 7 ) nest building from the outside of the nest , and ( 8 ) rubbing the anal - urogenital area toward the ceiling inside the nest . the sand goby male prepares mucus trails by rubbing the anal - urogenital area ( personal observation ) .
a study from the west coast of sweden , [ 19 ] ( where we find the traditionally reported size dimorphism ♂ > ♀ ) previously showed that over the short breeding season of the two - spotted goby there was a transition from a strong male–male competition with intensive courting males in the beginning of the season to a strong female–female competition with actively courting females towards the end of the season . this observation has recently been supported by further studies in the same location ( gullmarsfjorden , west coast of sweden ) , reporting that i ) the size of nest holding males decreased over the season—indicating a decrease in male—male competition [ 20 ] , and ii ) courtship is typically initiated by males and terminated by females early in the season , while the opposite pattern is found late in the season [ 21 ] .
in svensson and kvarnemo ( 2003 ) , sand goby males built much smaller nest openings in the presence of sneaker males , suggesting that the nest opening may work as a defense or camouflage against sneaker males . however , we have found no behavioral or genetic support for this to be true ( svensson , 2004 ) . similarly , in the azorean rock - pool blenny , parablennius sanguinolentus parvicornis , nests in the field with associated satellite males did not have larger openings than nests without satellites . on the other hand , nests with two openings had an associate satellite male much more often than nests with one ( oliveira et al . , 2002 ) . in the present study , we hypothesized that males should be more engaged in nest building when experiencing a sneaker male compared to when not , which was not the case .
marine ; brackish ; demersal ; oceanodromous ( ref . 51243 ) ; depth range 30 - ? m ( ref . 2058 ) . subtropical ; 47°n - 28°n , 6°w - 42°e
maturity : l m ? range ? - ? cm max length : 29 . 9 cm tl male / unsexed ; ( ref . 115022 ) ; max . reported age : 5 years ( ref . 4696 )
iteroparous , females produce more than one batch of eggs within the breeding season ( ref . 50965 ) .
miller , p . j . , 1979 . gobiidae . p . 483 - 515 . in j . c . hureau and th . monod ( eds . ) check - list of the fishes of the north - eastern atlantic and of the mediterranean ( clofnam ) . unesco , paris . vol . 1 . ( ref . 4345 )
) : 14 - 20 . 1 , mean 17 . 1 ( based on 26 cells ) .
phylogenetic diversity index ( ref . 82805 ) : pd 50 = 1 . 0000 [ uniqueness , from 0 . 5 = low to 2 . 0 = high ] .
bayesian length - weight : a = 0 . 00813 ( 0 . 00495 - 0 . 01335 ) , b = 3 . 08 ( 2 . 94 - 3 . 22 ) , in cm total length , based on lwr estimates for this species & ( sub ) family - body ( ref . 93245 ) .
trophic level ( ref . 69278 ) : 3 . 2 ±0 . 3 se ; based on diet studies .
resilience ( ref . 69278 ) : medium , minimum population doubling time 1 . 4 - 4 . 4 years ( tm = 2 - 3 ; fec > 5 , 000 ) .
prior r = 0 . 55 , 2 sd range = 0 . 29 - 1 . 04 , log ( r ) = - 0 . 6 , sd log ( r ) = 0 . 32 , based on : 1 k , 2 tgen , 1 tmax , 4 fec records
vulnerability ( ref . 59153 ) : moderate to high vulnerability ( 45 of 100 ) .
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bulgaria ; croatia ; france ( corsica , france ( mainland ) ) ; greece ( east aegean is . , greece ( mainland ) , kriti ) ; italy ( italy ( mainland ) , sardegna , sicilia ) ; libya ; monaco ; romania ; russian federation ( european russia , south european russia ) ; slovenia ; tunisia ; turkey ( turkey - in - asia , turkey - in - europe ) ; ukraine ( krym , ukraine ( main part ) )
the species is locally abundant and assumed to have a stable population , although harvested in some parts of its range .
this species is harvested for food in some parts of its range . the species has commercial importance in parts of its range , including in the black sea and in sivash ( berg 1965 ) . miller ( 1986 ) documents tissue contaminants ( pcbs , ddt etc . ) and heavy metal concentrations in fish from greek and italian habitats , which may affect consumers .
the species habitat may be impacted locally but there are no known widespread threats .
. however , it likely occurs in marine protected areas . it was assessed globally as data deficient in 1996 and as least concern in the mediterranean ( abdul malak
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aegean sea : 22700 - 787 ( 1 spc . ) , may 2000 , bozcaada island , 9 m , l . eryilmaz . inland water : 22700 - 626 ( 1 spc . ) , 1975 , bueyuekcekmece lagoon , istanbul , n . meriç .
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making sense of life as we know it , in the light of evolution .
however , sperm constitute only a small portion of the male ejaculate transferred to females during mating . the rest , up to 90 % , is composed of a myriad of proteins and other compounds that constitute the seminal fluid . in addition to being produced in abundance , seminal fluid proteins are also diverse . for example , scientists have found that males , of many species , produce dozens , if not hundreds , of different types of seminal fluid proteins . so , what then , do all these proteins do ? it turns out that these protein are involved in many different processes that indirectly influence male reproductive success , including influencing female physiology and interacting with a male’s own , as well as rival , sperm .
these fascinating results suggest many exciting avenues for future research . for example , from a mechanistic perspective : how exactly does seminal fluid composition vary between ‘guard’ and ‘sneaker’ males ? do many different proteins to differ in presence or concentration ? or does variation in one or very few seminal fluid proteins produce the observed differences in sperm performance ? furthermore , from an evolutionary perspective , we can ask : why do the males differ at all ? what constraints keep males from producing both high quality sperm , like the ‘sneakers’ , and high quality seminal fluid , like the ‘guards’ ?
locatello , l . , f . poli , and m . b . rasotto ( 2013 ) tactic - specific differences in seminal fluid influence sperm performance . proc r soc b 280 : 20122891 .
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this study was supported by m . u . r . s . t . 60 % .
fagen rm , young dy ( 1978 ) temporal patterns of behaviors : durations , intervals , latencies , and sequences . in : colgan pw ( ed ) quantitative ethology . wiley , new york , pp 79–114
haccou p , meelis e ( 1992 ) statistical analysis of behavioral data . oxford university press , oxford
kemadjou nijwa jr , muller p , klein r ( 2004 ) variations of sperm release in three batches of zebrafish . j fish biol 64 : 475–482
pall . ( pisces , gobiidae ) in laguna di venezia e osservazioni sulle caratteristiche dei riproduttori . lav soc ven sc nat 27 : 47–56
marconato a , rasotto mb , mazzoldi c ( 1996 ) on the mechanism of sperm release in three gobiid fishes ( teleostei : gobiidae ) . environ biol fish 46 : 321–327
parker ga ( 1990 ) sperm competition games : raffles and roles . proc royal soc lond b 242 : 121–126
scaggiante m , rasotto mb , romualdi c , pilastro a ( 2005 ) territorial male gobies respond aggressively to sneakers but do not ad just their sperm expenditure . behav ecol 16 : 1001–1007
siegel s , castellan nj ( 1992 ) statistica non parametrica . mcgraw - hill , new york , p 477
sokal rr , rohlf fj ( 1995 ) biometry , 3rd edn . freeman , new york , p 880
stoltz ja , neff bd ( 2006 ) sperm competition in a fish with external fertilization : the contribution of sperm number , speed and length . j evol biol , 1873–1871
malavasi , s . , lugli , m . , torricelli , p . et al . environ biol fish ( 2008 ) 82 : 279 . urltoken
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it is characterized by a squat body , swollen cheeks and big lips . it has not swimming - bladder , thus it can not do long moving and lives on the bottom , to which it sticks by the pelvic fin . the eyes are shifted to the top of the head , to allow a complete vision , even if it is covered with sand .
male looks after the eggs : it oxygenates them with its fins , defends from predators , and it cleans them with a germicidal mucus .
it lives in brackish environment , estuary and lagoons , on the muddy bottoms or in phanerogames prairies .
female goes in the den and lays the eggs sticking them to the stones that constitute the vault of the deg . hatching happens 5 - 6 days after fertilization .
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dipartimento di biologia , università di padova , viale g . colombo 3 , 35131 padova , italy e - mail : rasotto @ urltoken tel . : + 39 - 49 - 8276191 ; fax : + 39 - 49 - 8276199
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address correspondence to a . pilastro . e - mail : andrea . pilastro @ urltoken .
instead of adjusting sperm expenditure ( evans et al . , 2003 ; pilastro et al . , 2002 ; simmons and kvarnemo , 1997 ) , males could alternatively respond to the presence of competing males by guarding the mate or the nest ( alonzo and warner , 2000a ; birkhead and møller , 1992 ; komdeur , 2001 ; zamudio and sinervo , 2000 ) or making the nest less accessible to sneakers ( svensson and kvarnemo , 2003 ) . evidence of a trade - off between mate guarding and sperm expenditure has been found in some fish species , suggesting that both strategies are expensive in terms of time and / or energy ( candolin and reynolds , 2002 ; henson and warner , 1997 ; marconato et al . , 1996 ; warner et al . , 1995 ) .
fish were housed at chioggia hydrobiological station of the university of padova . at the end of the experiments they were released back into the wild . housing and experimental procedures have been conducted in accordance with italian national law ( dl116 / 92 ) .
plan view of the experimental tank ( 60 × 36 × 40–cm height ) . the tank was divided in two equal - sized compartments : the compartment of the territorial male contained a plastic nest ( 20 - cm long and with a diameter of 15 cm ) and a ripe female confined into a transparent plexiglas tube . the sneaker compartment contained zero , one , or four competitor sneakers , according to the treatment .
we tested all distributions for normality using shapiro - wilks test . some behavioral observations were not normally distributed , and we therefore used log transformation when appropriate . we compared territorial male behavior and sperm expenditure under three conditions , that is , with zero , one , and four sneakers , using a generalized linear model ( glm ) model in which territorial male behavior and sperm expenditure were the dependent variables , number of attending sneakers was the fixed factor , and identity of territorial male was the random factor ( to control for repeated observations ) . the test was repeated for each of the two phases of the experiment ( before and after female introduction ) . probabilities are two tailed . where not otherwise stated , mean ± se is reported . statistical analyses were performed using spss 12 .
time spent patrolling the territory ( time out of the nest , s ) by the territorial male according to the number of sneakers ( zero , one , or four ) and the phase of the experiment . ( a ) after the introduction of the sneakers and before the introduction of the female ( s out of nest 20 min −1 ) ; ( b ) after the introduction of the female ( s out of nest 20 min −1 ) . data were log transformed .
time spent attacking the sneakers ( i . e . , hitting the transparent divider , s ) by the territorial male according to the number of sneakers ( zero , one , or four ) and the phase of the experiment . ( a ) after the introduction of the sneakers and before the introduction of the female ( s of attack 20 min −1 ) ; ( b ) after the introduction of the female ( s of attack 20 min −1 ) . data were log transformed .
the results of glm in which territorial male behavior was the dependent variable , the number of attending sneakers the fixed factor , and territorial male identity the random factor are shown . interactions were nonsignificant and were removed from the model .
courtship behavior and sperm released of territorial male according to the number of sneakers ( zero , one , or four ) . ( a ) courtship rate of territorial male ( seconds of display 20 min −1 ) ; ( b ) sperm release ( log of sperm concentration , sperm per milliliter ) by the territorial male . data were log transformed .
each territorial male was tested in the three conditions ( with zero , one , and four attending sneakers ) .
we wish to thank the staff of the chioggia hydrobiological station for their kind support during the experiments and chris petersen , tommaso pizzari , and three anonymous referees for commenting on various versions of the manuscript . this study has been partially supported by institutional research grants ( ex60 % ) from the university of padova and grants from the italian ministry for research and university ( cofin2000 ) to a . p . and m . b . r .
a . allocation to mate guarding or increased sperm production in a mediterranean wrasse .
b . female choice , conflict between the sexes and the evolution of male alternative reproductive behaviours .
. sperm competition games : inter - and intra - species results of a continuous external fertilization model .
. sperm competition in birds : evolutionary causes and consequences . london : academic press .
. male mating behavior and ejaculate expenditure under sperm competition risk in the eastern mosquitofish .
. associations between body size , mating pattern , testis size and sperm lengths across butterflies .
. i pesci delle acque interne italiane . rome : istituto poligrafico e zecca dello stato .
. male and female alternative reproductive behaviors in fishes : a new approach using intersexual dynamics .
. mate guarding in the seychelles warbler is energetically costly and adjusted to paternity risk .
. on the mechanism of sperm release in three gobiid fishes ( teleostei : gobiidae ) .
. is sperm cheap ? limited fertility and female choice in the lemon tetra ( pisces , characidae ) .
. sperm competition and the evolution of ejaculates : towards a theory base . in : sperm competition and sexual selection ( birkhead tr , møller ap , eds ) . london : academic press ; 1–54 .
. sperm competition games : individual assessment of sperm competition intensity by group spawners .
. sperm competition and the evolution of animal mating systems . london : academic press .
. sperm competition in fishes : the evolution of testis size and ejaculate characteristics .
. sexual conflict : males with highest mating success convey the lowest fertilization benefits to females .
. fishes of the north - eastern atlantic and the mediterranean . paris : unesco .
. polygyny , mate - guarding , and posthumous fertilization as alternative male mating strategies .
adepartment of biology , university of padova , via u . bassi 58 / b , i - 35131 padova , italy
bcribi biotechnology centre , university of padova , via u . bassi 58 / b , i - 35131 padova , italy
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this study aims to extend the current knowledge on biology aspects , such as age and growth , to the gulf of gabes ( southeast of tunisia ) . the determination of the von bertalanffy growth parameters of…
[ more ]
diet shifts of gobius paganellus ( teleostei , gobiidae ) from the gulf of gabes ( central mediterranean . . .
the aim of this paper is to describe the diet of the population of gobius paganellus from the gulf of gabes , looking at seasonal and ontogenetic shifts and identifying the main preys . this species is an intertidal fish sparsely distributed on the tunisian coast . a total of 629 specimens with total lengths ranging from 8 . 9 to 14 . 3 cm were captured on the gulf of gabes . in the laboratory , the tl . . . [ show full abstract ]
zosterisessor ophiocephalus is currently an important component of the eastern mediterranean inshore fisheries . in tunisia it was recorded for the first time in the gulf of gabes in 1993 , where it is now an important fished species . in this study age and growth parameters were determined in the gulf of gabes ( southeast of tunisia ) based on otolith analysis of 824 specimens caught between . . . [ show full abstract ]
the retinal vascularization of zosterisessor ophiocephalus is described by scanning electron microscopy of vascular corrosion casts . the retina is vascularized sclerad by the choroidal body and the choriocapillaris , and vitread by the lentiform body and by a dense network of hyaloid vessels . in the bodies there is a parallel arrangement of capillaries indicating a counter current exchange mechanism . the well developed vascularization and its correlation with the hypoxic conditions of the muddy habitat of the species are discussed .
ali , m . a . , m . anctil & h . m . mohideen . 1968 . structure rétinienne et la vascularization intraoculaire chez quelque poissons marins de la région de gaspé . can . j . zool . 46 : 729–745 .
anctil , m . 1968 . intraocular vascular supply in some marine teleosts . rev . can . biol . 27 : 347–355 .
barnett , c . h . 1951 . the structure and function of the choroidal gland in teleostean fish . j . anat . 85 : 113–119 .
collin , s . p . 1989 . topographic organization of the ganglion cell layer and intraocular vascularization in the retinae of two teleosts . vision res . 29 : 765–775 .
copeland , d . e . 1980 . functional vascularization of the teleost eye . pp . 219–280 .
: j . a . zadunaisky & h . davson ( ed . ) current topics in eye research , volume 3 , academic press , new york .
fonner , d . b . , j . r . hoffert & p . o . fromm . 1973 . the importance of the counter current oxygen multiplier mechanism in maintaining retinal function in the teleost . comp . biochem . physiol . 46a : 559–567 .
hanyu , i . 1959 . on the falciform process , vitreal vessels and other structures of the teleost eye . i . various types and their interrelationship . bull . japan . soc . sci . fish . 25 : 595–613 .
kenchington , w . & s . choy . 1989 . enhanced vascularization of the central nervous system in two species of mud - burrowing fish . env . biol . fish . 24 : 237–240 .
lametschwandter , a . , u . lametschwandter & t . weiger . 1984 . scanning electron microscopy of vascular corrosion caststechnique and applications . scan . electron . microscopy ii : 663–695 .
lazzari , m . , v . franceschini , g . minelli & f . ciani . 1993 . choroidal and iris angioarchitecture of the newt — a scanning electron - microscopic study of vascular corrosion casts . experientia 49 : 277–281 .
lythgoe , j . n . 1979 . ecology of vision . clarendon press , oxford . 244 pp .
: p . j . p whitehead , m . - l . bauchot , j . - c . hureau , j . nielsen & e . tortonese ( ed . ) fishes of the north - eastern atlantic and the mediterranean , volume 3 , unesco , paris .
) study of micro - corrosion casts . cell tissue res . 249 : 101–209 .
. scanning electron - microscopic study of vascular corrosion casts . cell tissue res . 250 : 465–473 .
munk , o . 1970 . on the occurrence and significance of horizontal band - shaped retinal areas in teleosts . vidensk . meddr . dansk . naturh . foren . 133 : 85–120 .
: coexistence of falciform process and vitreal vessels . env . biol . fish . 36 : 385–388 .
negishi , k . & k . sugawara . 1973 . evidence for anoxia sensitivity of the synaptic region at the outer plexiform layer in the fish retina . vision res . 13 : 983–987 .
nicol , j . a . c . 1989 . the eyes of fishes . clarendon press , oxford . 308 pp .
of the seas and freshwaters in italy ) . comitato talassografico italiano memoria ccxlii . 169 pp .
( pallas , 1811 ) ( pisces , gobiidae ) . ph . d . thesis , university of ljubljana , ljubljana , 140 pp .
, teleostei , gobiidae ) under different light intensities : a behavioural and morphological study . boll . zool . 61 , supp1 . 1994 : 36 .
pagotto , g . & g . campesan . 1980 . abitudini alimentari di specie ittiche della laguna di venezia . i° contributo :
( pallas , 1811 ) ( pisces , gobiidae ) , adulto ( food selection in fish species from the lagoon of venice . ist report :
( pallas , 1811 ) ( pisces , gobiidae ) , adults ) . atti museo civico storia naturale trieste 32 : 1–18 .
sivak , j . g . & p . i . roth . 1978 . possible role of fundus circulation as an intraocular colour filter in certain fishes . rev . can . biol . 37 : 85–90 .
vernberg , j . b . & f . j . vernberg . 1972 . environmental physiology of marine animals . springer verlag , berlin . 346 pp .
wittenberg , j . b . & b . a . wittenberg . 1974 . the choroid rete mirabile of the fish eye . i . oxygen secretion and structure : comparison with the swimbladder rete mirabile . biol . bull . 146 : 116–136 .
ota , d . & lahnsteiner , f . environ biol fish ( 1996 ) 45 : 319 . urltoken
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contributed equally to this work with : a . c . utne - palm , k . eduard
copyright : © 2015 utne - palm et al . this is an open access article distributed under the terms of the creative commons attribution license , which permits unrestricted use , distribution , and reproduction in any medium , provided the original author and source are credited
data availability : the data are all contained within the paper and its supporting information files .
funding : this study was funded by the university of bergen through the contributing work of a master student .
in common with most teleost fishes displaying alternative mating tactics , a conditional tactic seems to be most common in species of the family gobidae . in gobies , larger males usually adopt the dominant mating tactic ( territorial nest holders ) , while the smaller males adopt the parasitic tactic ( sneakers ) [ 12 – 14 ] . even more drastically , some gobies change their sex and hence their reproductive tactic completely [ 15 ] .
to make it easier to distinguish between the lines in cases where they overlap , the lines for early and late season are placed 0 . 015 units to the left and right on the x - axis , respectively . average lengths related to season are marked with arrows . sample size females n = 600 , males n = 533 .
the present study was undertaken to determine firstly , whether the small males discovered in the bergen population display a parasitic spawning tactic . secondly , if so we wanted to determine whether the prevalence of this spawning tactic changes over the course of the breeding season .
fish samples were collected during the early ( may ) and late ( july ) breeding season in 2006 and 2008 , using a beach seine ( 30 m long , 3 m high , mesh size 3–5 mm in the catch area ) . some modifications were made to the seine to ensure that it followed the topography without lifting off the bottom by the macro algae ; this included additional weights to the bottom line and floaters on the top line . to ensure that a true representative sample of nest holding males was collected ( hiding in their nest on the bottom ) one seine net was first set to effectively enclose our sampling area , after which the enclosed area was sampled twice with a second beach seine , before finally the outer seine was hauled in .
all statistics and plots were performed using r version 3 . 2 . 2 ( r development core team 2015 , urltoken ) . fish size was compared between sex and season by using a linear mixed effects model ( lme ) with the predictor total length of the fish ( cm ) and the two categorical predictors season and sex . station was set as a random effect factor . sample sizes for males and females were 533 and 600 , respectively . demography was investigated by making simple frequency plots of fish lengths depending on sex and season . additionally , for each sex we made size - frequency distributions over early and late season for the 25 % smallest and largest fish , respectively . this allowed us to get a clearer picture of eventual demographic differences between males and females over the season .
for male fish , the investment in seminal duct gland ( sdg ) and testes were compared between early and late season , i . e , may vs july . we did this by using five different models to cover the most commonly used methods from earlier studies e . g . [ 24 , 33 ] .
model a , gsi : the response variable was the gonadosomatic index ( gsi ) and the two predictors were total length and season .
model b , sdgi : the response variable was the seminal duct gland index ( sdgi ) and the two predictors were total length and season .
model c , testis mass : the response variable was log ( testis weight ) and the predictors were log ( soma mass ) and season .
model d , sdg : the response variable was log ( seminal duct gland weight ) and the two predictors were log ( soma mass ) and season .
model e , relative investment in sdg : the response variable was log ( seminal duct gland weight / testes weight ) and the two predictors were log ( soma mass ) and season .
in the models about sdg and testes investment the sample size was reduced from 533 to 506 as we were lacking sdg and testes measurements for 27 of the fish ( due to problems separating the testes and sdg during dissection ) .
condition factor was analysed for females and males in one model , allowing for a three way interaction between the predictors ; total length of the fish , season and sex . we used an lme for this purpose and the random effect factor was the same as explained in the models above .
based on histological findings on whether the sdgs contained sperm or not we divided the males into either “sneakers” ( size range with sperm in sdg ) and “territorial” males ( size range without sperm in sdg ) for early and late season . finally , we performed a linear regression ( log ( y ) = log ( a ) + b * log ( x ) , where y refers to sdg and testes weight and x to soma weight ) , to look at possible difference in “b” ( slope ) between groups ( sneakers and territorial ) and season [ 33 , 36 , 37 ] .
all aspects of this study , including field sampling , fish transportation , and killing of fish ( by overdose of ms222 ) , were approved in advance by the animal care committee at the university of bergen . this committee closely follows the strict regulations of the european commission directive for animal used for scientific purposes . collection of fish along the norwegian coast does not require permission . the field collections did not involve endangered or protected species .
the comparison of fish size depending on sex and season revealed no interaction between the two predictors , i . e . the change in size when going from early to late season is the same for the two sexes ( lme ; f 1 , 1127 = 1 . 385 , p = 0 . 240 ) . however , there was a significant effect of both sex and season , where the mean size of males is significantly smaller than females ( lme ; f 1 , 1127 = 98 . 185 , p < 0 . 001 , fig 1 ) and mean size is significantly smaller in the early compared to the late breeding season ( lme ; f 1 , 1127 = 22 . 087 , p < 0 . 001 , fig 1 ) . among all male fish sampled in this study , the ones belonging to the size range representing the 25 % smallest males are more represented in the early compared to the late breeding season , with 100 and 33 small males sampled in the early and late breeding season , respectively . the same trend was also observed for the 25 % largest males with 82 and 51 large males in the early and late breeding season , respectively . for females , the 25 % smallest individuals were represented with 92 and 58 females sampled in the early and late breeding season , respectively , while the 25 % largest females , were represented with 66 and 84 females sampled in the early and late breeding season , respectively . thus , our results indicate a higher mortality or a different growth rate among larger males compared to females in the late breeding season .
the model for gsi showed a significant interaction between the two predictors total length ( including second order polynomial ) and season ( lme ; f 2 , 498 = 21 . 763 , p < 0 . 001 , fig 2 ) . this indicates that the relationship between gsi and fish length changes from early to late in the breeding season . fig 2 shows that this is mainly due to the high proportion of small fish having high gsi values in the early compared to the late breeding season . this is supported by the treatment contrasts from the model ( the summary output of r ) : early season has significantly higher mean than late season ( contrast between mean of early and late season ; t 498 = 14 . 256 , p < 0 . 001 ) , and the relative decrease in gsi depending on total length is steeper in early compared to late season ( contrasts between first order polynomials of early vs late season ; t 498 = 6 . 483 , p < 0 . 001 ) . the untransformed mean gsi in early and late season is 1 . 981 ( se = 0 . 084 ) and 0 . 778 ( se = 0 . 026 ) , respectively . for a complete list of results from the model see supporting information material ( model a in s1 file ) .
scatterplots showing gonadosomatic index gsi ( gsi = ( testes weight + sdg weight ) / body weight * 100 ) related to total length for early and late reproductive season .
the solid lines represent the mixed effect model . the grey horizontal lines represent the average of the full dataset—independent of season and soma mass . early season has significant higher mean than late season and the relative decrease in gsi depending on total length is steeper in early compared to late season ( for more details see results ) . n = 506 .


the sharpsnout stingray or wingfin stingray ( dasyatis geijskesi ) is a species of stingray in the family dasyatidae , found from off venezuela to northern brazil .

it inhabits shallow , brackish water , shifting towards the coast in the dry season and away from it in the rainy season .

typically measuring 70 cm ( 28 in ) across , this dark brown ray is easily identifiable by its long , projecting snout and elongated , acutely pointed pelvic fins .

its diet consists of bottom-dwelling invertebrates .

reproduction is aplacental viviparous , with females bearing one to three pups annually .

naturally uncommon and slow-reproducing , the sharpnose stingray is under pressure by both artisanal and commercial fisheries , leading the international union for conservation of nature ( iucn ) to assess it as near threatened .

sharpsnout stingray

wikipedia article copyright notice : this article is licensed under the gnu free documentation license . it uses material from the wikipedia article
sharpsnout stingray
.
glenn , c . r . 2006 .
earth ' s endangered creatures - sharpsnout stingray facts
( online ) - licensed article from wikipedia : the free encyclopedia . accessed
; the roughtail stingray , d . centroura ( mitchill , 1815 ) ; the wingfin stingray , d . geijskesi boeseman , 1948
facts summary : the sharpsnout stingray ( dasyatis geijskesi ) is a species of concern belonging in the species group
fishes
and found in the following area ( s ) : brazil , french guiana , guyana , senegal , trinidad and tobago , venezuela . this species is also known by the following name ( s ) : wingfin stingray .
dasyatis guttata bloch & j . g . schneider , 1801 ( longnose stingray )
dasyatis margaritella compagno & t . r . roberts , 1984 ( pearl stingray )
bennett ' s stingray , dasyatis bennetti ( müller & henle , 1841 ) .
pale - edged stingray , dasyatis zugei ( müller & henle , 1841 ) .
; the longnose stingray d . guttata ( bloch & schneider , 1801 ) ; the brazilian large - eyed stingray , d . marianae gomes , rosa & gadig , 2000
dasyatis parvonigra last & w . t . white , 2008 ( dwarf black stingray )
short - tail stingray or bull ray , dasyatis brevicaudata ( hutton , 1875 ) .
round stingray , taeniura grabata ( é . geoffroy saint - hilaire , 1817 ) .
stingray city in grand cayman allows swimmers , snorkelers , and divers to swim with and feed the stingrays .
historical and anecdotal evidence strongly suggest that the once - abundant estuary stingray has declined substantially across its range .
meyer , p . 1997 . stingray injuries . wilderness environ med 8 ( 1 ) : 24 - 8 .
requirements of the estuary stingray appear to be rather stringent , as significant numbers are only found at particular locations .
a stingray buried in the sand in saba . stingrays can be hard to see when they cover themselves with substrate .
^ estuary stingray ( 31 august 2007 ) . queensland department of environment and resource management . retrieved 6 november 2011 .
have been reported for the southwestern atlantic ( in brazilian waters ) : the southern stingray , d . americana hildebrand & schroeder , 1928
the queensland government has listed the estuary stingray on the back on track species prioritisation framework , to facilitate the development of conservation measures .
a stingray in dark waters . stingrays are dangerous for humans because it is hard to see them when they ' re in dark waters .
while not independently valuable as a food source , the stingray ' s capacity to damage shell fishing grounds can lead to bounties being placed on their removal .
martin , r . a . 2008 . biology of sharks and rays : stingray city limits . reefquest centre for shark research . retrieved june 2 , 2008 .
passarelli , n . , and a . piercy . 2008 . atlantic stingray . florida museum of natural history , ichthyology department . retrieved june 2 , 2008 .
habitat degradation is another major threat to the estuary stingray , especially given its habitat specificity . its range encompasses some of the most urbanized areas in australia , where there is extensive
dasyatis ( greek
dasys
meaning rough or dense and
batus
meaning skate ) is a genus of stingray . the members of the genus neotrygon were formerly included in dasyatis .
, and the bluntnose stingray , d . say ( lesueur , 1817 ) . the other dasyatid stingrays known from brazil are : the pelagic stingray , pteroplatytrygon violacea ( bonaparte , 1832 ) and the chupare stingray , himantura schmardae ( werner , 1904 ) ( dasyatidae ) ( ribeiro , 1907 , 1923 ; figueiredo , 1977 ; charvet - almeida et . al . , 2000 , gomes & gadig , 2003 ) . the atlantic stingray d . sabina ( lesueur , 1824 ) , according to garman ( 1913 ) , has been recorded from north carolina ( usa ) to brazil . bigelow & schroeder ( 1953 : 376 ) , cited the brazilian record of this species , referring to it as
. . . probably not on good evidence
. herein we describe a new species of dasyatis
↑ t . r . roberts , makararaja chindwinensis , a new genus and species of freshwater dasyatidid stingray from upper myanmar , the natural history bulletin of the siam society 54 ( 2006 ) : 285–293 .
flint , d . , and w . sugrue . 1999 . stingray injuries : a lesson in debridement . new zealand med j 112 ( 1086 ) : 137 - 8 . retrieved june 2 , 2008 .
although edible , stingrays are not a dietary staple and are not considered a high - quality food . however , they are consumed , including fresh , dried , and salted ( mceachran 2004 ) . stingray recipes abound throughout the world , with dried forms of the wings being most common . for example , in singapore and malaysia , stingray is commonly barbecued over charcoal , then served with spicy sambal sauce . generally , the most prized parts of the stingray are the wings , the
cheek
( the area surrounding the eyes ) , and the liver . the rest of the ray is considered too rubbery to have any culinary uses .
the estuary stingray ( dasyatis fluviorum ) , also called the estuary stingaree or brown stingray , is a species of stingray in the family dasyatidae . endemic to eastern australia , it typically inhabits shallow , mangrove - lined tidal rivers , estuaries , and bays in southern queensland and new south wales . this yellow - brown to olive ray grows to at least 93 cm ( 37 in ) across . it has a diamond - shaped pectoral fin disc and a mostly smooth , whip - like tail bearing both dorsal and ventral fin folds . it can additionally be identified by its long , narrow nostrils and the row of thorns along the midline of its back .
the estuary stingray has a diamond - shaped pectoral fin disc about as wide as long , with gently convex anterior margins and broadly rounded outer corners . the snout is wide and triangular , and tapers to a point . the small , widely spaced eyes are immediately followed by the
hugo ricardo secioso santos , ulisses leite gomes , patricia charvet - almeida ( 2004 ) : a new species of whiptail stingray of the genus dasyatis rafinesque , 1810 from the southwestern atlantic ocean ( chondrichthyes : myliobatiformes : dasyatidae ) . zootaxa 492 , 1 - 12 : 1 - 1 , urltoken
in the cayman islands , there are several dive sites called stingray city , grand cayman , where divers and snorkelers can swim with large southern stingrays ( dasyatis americana ) and feed them by hand . there is also a
stingray city
in the sea surrounding the caribbean island of antigua . it consists of a large , shallow reserve where the rays live , and snorkeling is possible . in belize , off the island of ambergris caye there is a popular marine sanctuary called hol chan . here divers and snorkelers often gather to watch stingrays and nurse sharks that are drawn to the area by tour operators who feed the animals .
↑ p . r . last , b . m . manjaji , and g . k . yearsley , pastinachus solocirostris sp . nov . , a new species of stingray ( elasmobranchii : myliobatiformes ) from the indo - malay archipelago , zootaxa 1040 ( 2005 ) : 1 - 16 . retrieved june 2 , 2008 .
santos , h . r . s . and m . r . de carvalho . 2004 . description of a new species of whiptailed stingray from the southwestern atlantic ocean ( chondrichthyes , myliobatiformes , dasyatidae ) . boletim do museu nacional do rio de janeiro , nova série . zoologia no . 516 : 1 - 24 .
stingray is the common name for any of the various cartilaginous fish comprising the family dasyatidae , characterized by enlarged and flat pectoral fins continuous with the side of the head , no caudal fin , eyes on the dorsal surface , and narrow , long , and whip - like tail , typically with one or more venomous spines . marine , brackish water , and freshwater species are known .
stingrays are popular targets of ecotourism . dasyatids are not normally visible to swimmers , but divers and snorkelers may find them in shallow sandy waters . usually very docile , their usual reaction being to flee any disturbance . nevertheless , certain larger species may be more aggressive and should only be approached with caution by humans , as the stingray ' s defensive reflex may result in serious injury or even death .
dasyatids generally do not attack aggressively or even actively defend themselves . when threatened , their primary reaction is to swim away . however , when attacked by predators or stepped on , the barbed stinger in their tail is whipped up . this attack is normally ineffective against their main predator , sharks . the breaking of the stinger in defense is non - fatal to the stingray , as it will be regrown .
some adult rays may be no larger than a human palm , while other species , like the short - tail stingray , may have a body of six feet in diameter , and an overall length , including their tail , of fourteen feet . stingrays can vary from gray to bright red in color and be plain or patterned . dasyatids are propelled by motion of their large pectoral fin ( commonly mistaken as
wings
) .
depending on the size of the stingray , humans are usually stung in the foot region . surfers or those who enter waters with large populations of stingrays have learned to slide their feet through the sand rather than stepping , as the rays detect this and swim away . stamping hard on the bottom as one treads through murky water will also cause them to swim away . humans who harass stingrays have been known to be stung elsewhere , sometimes leading to fatalities . contact with the stinger causes local trauma ( from the cut itself ) , pain and , swelling from the venom , and possible later infection from bacteria . immediate injuries to humans include , but are not limited to , poisoning , punctures , severed arteries , and possibly death . fatal stings are very rare . on september 4 , 2006 , australian wildlife expert and television personality steve irwin was pierced in the chest by a stingray barb while snorkeling in australia and died shortly after .
while the estuary stingray has gained infamy for consuming farmed shellfish such as oysters , it mainly feeds on crustaceans and polychaete worms . it is aplacental viviparous , with the unborn young sustained to term by maternal histotroph (
uterine milk
) . once common , this species has apparently declined across much of its range , likely from a combination of habitat degradation , mortality from commercial and recreational fishing , and persecution by shellfish farmers . as a result , the international union for conservation of nature ( iucn ) has assessed it as vulnerable .
this stingray is caught as a bycatch ( hooking , netting and entanglement ) in artisanal and industrial fisheries aimed at large catfish that are present in the amazon estuary . this species is also taken regionally as a secondary option subsistence food source . fishery industries tend to show an interest in large dasyatids as a source of minced fish products , implying that exploitation pressure and population depletion may increase in the future . intrinsic factors probably also represent a threat for this species as to most other elasmobranchs species ( camhi et al . 1998 ) , particularly given this species ' large size and low fecundity .
justification : this is an amended version of the 2006 assessment to accommodate the change in genus name . a large , relatively uncommon , stingray that is found on the northern coast of south america in the western central and southwest atlantic , mainly in estuarine and coastal areas near the amazon river mouth . very limited data are available about the habitat and ecology of this species . pregnant females are observed with only one to three pups per litter . population trends and dynamics are completely unknown . the species is taken as bycatch by both artisanal and industrial fisheries , which continue to be unregulated . it is used regionally as a subsistence food source but as a secondary option due to its dark ( reddish ) coloured flesh . fishery industries tend to show an interest in large dasyatids as a source of minced fish products , implying that exploitation pressure and population depletion may increase in the future . base - line studies and fishery monitoring are required for this species , but given its inshore occurrence in fished regions , relatively restricted range and habitat , biology and apparent interest to industrial fisheries , the species is assessed as near threatened .
treatment for stings includes application of near - scalding water , which helps ease pain by denaturing the complex venom protein , and antibiotics . immediate injection of local anesthetic in and around the wound is very helpful , as is the use of opiates such as intramuscular pethidine . local anesthetic brings almost instant relief for several hours . any warm to hot fluid , including urine , may provide some relief . vinegar and papain are ineffective . ( urine is a folk remedy for box jellyfish stings but is ineffective for such , whereas vinegar is effective for box jellyfish stings . ) pain normally lasts up to 48 hours , but is most severe in the first 30–60 minutes and may be accompanied by nausea , fatigue , headaches , fever , and chills . all stingray injuries should be medically assessed ; the wound needs to be thoroughly cleaned , and surgical exploration is often required to remove any barb fragments remaining in the wound . following cleaning , an ultrasound is helpful to confirm removal of all the fragments ( flint and sugrue 1999 ) . not all remnants are radio - opaque ; but x - ray radiography imaging may be helpful where ultrasound is not available .
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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 .
eschmeyer , w . n . , fricke , r . and van der laan , r . ( eds ) . 2016 . catalog of fishes : genera , species , references . updated 29 september 2016 . available at : urltoken . ( accessed : 29 september 2016 ) .
last et al . ( 2016 ) placed dasyatis colarensis , d . garouaensis , d . geijskesi , d . margarita , d . margaritella , and urogymnus ukpan within their newly described genus fontitrygon . the two western atlantic species ( f . colarensis and f . geijskesi ) differ significantly from the other taxa in this genus and may prove to be non - congeneric with the four species from western african ( last et al . 2016 ) .
this species has a relatively restricted geographic range ( northern atlantic coast of south america ) , ranging from northern brazil to the venezuelan coast , including french guiana , guyana , suriname and trinidad and tobago ( cervigón et al . 1992 , uyeno et al . 1983 ) . it is found mainly in the region of influence of the amazon river discharge . during the dry season it is found closer to the shore and is present in the marajó bay region ( authors ' observations ) .
this species is not very common as other dasyatid species throughout its distribution range . population size , trends and dynamics remain unknown for this species .
research actions are required for this species . preliminary base - line studies are in progress to obtain further data on the biology , ecology , uses and fishery data of this species . captures should also be monitored to observe if they are within a sustainable range and to verify if there are tendencies of increase . industries that recently began processing minced fish products are very likely to show an interest for this species as for other dasyatids . habitat maintenance and conservation are desired for most coastal species that are likely to be susceptible to environmental changes . education and public awareness could also contribute to the understanding that future increases in catches should be carefully studied and monitored . the development and implementation of management plans ( national and / or regional e . g . , under the fao international plan of action for the conservation and management of sharks : ipoa - sharks ) are required to facilitate the conservation and sustainable management of all chondrichthyan species in the region . see anon . ( 2004 ) for an update of progress made by nations in the range of f . geijskesi .
charvet - almeida , p . & de almeida , m . p . 2016 .
to make use of this information , please check the < terms of use > .
marine ; brackish ; demersal ; depth range 5 - 80 m ( ref . 114953 ) , usually 5 - 25 m ( ref . 5217 ) . tropical
maturity : l m ? range ? - ? cm max length : 150 cm wd male / unsexed ; ( ref . 5217 ) ; common length : 70 . 0 cm wd male / unsexed ; ( ref . 5217 )
disc is narrowly projecting to snout , pelvic fins with long anterior margins . narrowly pointed falcate outer corners . upper surface dark brown , lower surface pale with darker margins and teeth as yellowish white ( ref . 6902 ) .
found in shallow waters on sandy bottoms generally between 5 and 25 m depth . reported from a depth of 810 m ( ref . 13608 ) . ovoviviparous ( ref . 50449 ) .
exhibit ovoviparity ( aplacental viviparity ) , with embryos feeding initially on yolk , then receiving additional nourishment from the mother by indirect absorption of uterine fluid enriched with mucus , fat or protein through specialised structures ( ref . 50449 ) . distinct pairing with embrace ( ref . 205 ) .
cervigón , f . , r . cipriani , w . fischer , l . garibaldi , m . hendrickx , a . j . lemus , r . márquez , j . m . poutiers , g . robaina and b . rodriguez , 1992 . fichas fao de identificación de especies para los fines de la pesca . guía de campo de las especies comerciales marinas y de aquas salobres de la costa septentrional de sur américa . fao , rome . 513 p . preparado con el financiamento de la comisión de comunidades europeas y de norad . ( ref . 5217 )
) : 27 - 28 . 3 , mean 27 . 6 ( based on 302 cells ) .
phylogenetic diversity index ( ref . 82805 ) : pd 50 = 0 . 5156 [ uniqueness , from 0 . 5 = low to 2 . 0 = high ] .
bayesian length - weight : a = 0 . 00646 ( 0 . 00274 - 0 . 01522 ) , b = 3 . 11 ( 2 . 90 - 3 . 32 ) , in cm total length , based on lwr estimates for this ( sub ) family - body shape ( ref . 93245 ) .
trophic level ( ref . 69278 ) : 3 . 7 ±0 . 3 se ; based on size and trophs of closest relatives
resilience ( ref . 69278 ) : low , minimum population doubling time 4 . 5 - 14 years ( assuming fecundity < 100 ) .
vulnerability ( ref . 59153 ) : very high vulnerability ( 90 of 100 ) .
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5 . biological resource use - > 5 . 4 . fishing & harvesting aquatic resources - > 5 . 4 . 3 . unintentional effects : ( subsistence / small scale ) [ harvest ] ♦ timing : ongoing 5 . biological resource use - > 5 . 4 . fishing & harvesting aquatic resources - > 5 . 4 . 4 . unintentional effects : ( large scale ) [ harvest ] ♦ timing : ongoing
0 . root - > 100 . 1 . old 1 . 1 . 1 - policy - base actions - > management plans - > development 1 . research - > 1 . 2 . population size , distribution & trends 1 . research - > 1 . 3 . life history & ecology 1 . research - > 1 . 6 . actions 3 . monitoring - > 3 . 1 . population trends
anonymous . 1979 . groot surinaams kookboek met exotische creoolse , hindoestaanse , indonesische , chinese en europese recepten . stichting eerste surinaamse huishoud en nijverheidsschool te paramaribo .
anonymous . 2004 . report on the implementation of the un fao international plan of action for sharks ( ipoa–sharks ) . ac20 inf . 5 . twentieth meeting of the cites animals committee , johannesburg ( south africa ) , 29 march–2 april 2004 .
boesman , m . 1948 . some preliminary notes on surinam sting rays , including the description of a new species . zoologische mededeelingen 31–47 .
bor , p . h . f . 2002 . nederlandse naamlijst van de recente haaien en roggen ( chondrichthyes : elasmobranchii ) van de wereld . urltoken
camhi , m . , fowler , s . , musick , j . bräutigam , a . and fordham , s . 1998 . sharks and their relatives : ecology and conservation . occasional paper of the iucn species survival commission 20 .
cervigón , f . , cipriani , r . , fischer , w . , garibaldi , l . , hendrickx , m . , lemus , a . j . and claro , r . 1994 . características generales de la ictiofauna . in : r . claro ( ed . ) ecología de los peces marinos de cuba . pp : 55–70 . instituto de oceanología de la academia de ciencias de cuba y centro de investigaciones de quintana roo .
cervigón , f . , cipriani , r . , fischer , w . , garibaldi , l . , hendrickx , m . , lemus , a . j . , márquez , r . , poutiers , j . m . , robaina , g . and rodriguez , b . 1992 . fichas fao de identificación de especies para los fines de la pesca . guía de campo de las especies comerciales marinas y de aquas salobres de la costa septentrional de sur américa . preparado con el financiamento de la comisión de comunidades europeas y de norad . food and agricultural organization of the united nations ( fao ) , rome , italy .
charvet - almeida , p . 2001 . ocorrência , biologia e uso das raias de água doce na baía de marajó ( pará , brasil ) , com ênfase na biologia de plesiotrygon iwamae ( chondrichthyes : potamotrygonidae ) . masters dissertation . belém , museu paraense emílio goeldi & universidade federal do pará .
compagno , l . j . v . 1999 . checklist of living elasmobranchs . in : w . c . hamlett ( ed . ) sharks , skates , and rays : the biology of elasmobranch fishes . john hopkins university press , maryland . p . 471 - 498 .
iucn . 2016 . the iucn red list of threatened species . version 2016 - 3 . available at : urltoken . ( accessed : 07 december 2016 ) .
iucn ssc shark specialist group . specialist group website . available at : urltoken .
last , p . r . , naylor , g . j . p . and manjaji - matsumoto , b . m . 2016 . a revised classification of the family dasyatidae ( chondrichthyes : myliobatiformes ) based on new morphological and molecular insights . zootaxa 4139 ( 3 ) : 345 - 368 . urltoken
uyeno , t . , matsuura k . and fujii , e . ( eds ) 1983 . fishes trawled off suriname and french guiana . japan marine fishery resource research center , tokyo , japan .
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the tasmanian devil is endemic to australia . although this species is called tiger ( named for its stripes ) and wolf ( due to its canid - like appearance ) , it is not a member of the cat or wolf family . it is a member of the marsupial family . other members of this family include kangaroos and koala bears .
the last known tasmanian tiger died in a zoo in hobart , tasmania in 1936 , but there have been hundreds of unconfirmed sightings , and a reserve has been set up in southwestern tasmania in the hopes that possible surviving individuals can have adequate habitat .
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there are around 69 species in this family . most species are found in shallow tropical and subtropical oceans around the world , although some species in africa and south america are found in rivers and lakes .
they have rounded or oval shaped pectoral fins and long , whip - like tails with one or more poisonous barbed spines on the near the base of their tails . they have small mouths , no anal fin , and no caudal fin .
most of the species in this family spend their time partially buried under the sand or mud on the ocean floor . they use their pectoral fins to stir up worms , crustaceans , and mollusks . they are viviparous . that means they give birth to live young .
least concern near threatened vulnerable endangered critically endangered extinct in the wild extinct status and range is taken from icun redlist . if no status is listed , there is not enough data to establish status .
disc very thin , rhomboidal , about as wide as long , angular at front , outer and rear corners abruptly rounded or angular ; snout long , protruding beyond front margin of disc , its length > 4 times distance between eyes ; pelvic fins very wide and pointed laterally ; nostrils with a large fringed curtain between them and the mouth ; floor of the mouth has fleshy papillae ; teeth with low oval or angular crowns ; tail long and slender , ending in a point ; tail base broad , depressed ; 1 large , serrated , venomous spine on top of tail ; no tail fin or dorsal fins , tail without dorsal keel behind the spine and with a ventral fleshy ridge , height of the ventral ridge ½ that of height of the tail above it ; a single row of tubercles along the midline of the back from the nape to the tail base .
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volume 107 , number 1 , pages 19 - 30 , doi : 10 . 3354 / dao02661
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this study proved the illegal commercialization of pristis perotteti , a critically endangered sawfish species in brazil .
dna sequences of two mitochondrial genes were highly effective to discriminate 12 ray and eight shark species .
this molecular approach can be used in authenticity and forensics of food products derived from this fish group .
pristis perotteti , the largetooth sawfish , is one of most endangered elasmobranchs because of fisheries and habitat degradation . its commercialization in brazil is prohibited , but fresh or salted fillets of this fish can be found in markets , labeled as “sharks” . in this study we performed genetic analyses on “shark” samples from two important fishery - trading ports in northern brazil ( vigia and bragança ) . based on partial dna sequences of the mitochondrial 16s and cyt b genes , 24 ( 55 % ) out of 44 samples were unequivocally identified as p . perotteti while the others comprised eight species of the families carcharhinidae and ginglymostomatidae . these results show that fishing surveillance and monitoring have not been effective to prohibit the commercialization of this highly endangered species .
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comprises 37 species and occurs worldwide ( compagno , 1999a , b and gomes et al . 2000 ) . six species of dasyatis
depth range based on 2708 specimens in 28 taxa . water temperature and chemistry ranges based on 963 samples . environmental ranges depth range ( m ) : 0 - 479 temperature range ( °c ) : 7 . 337 - 28 . 215 nitrate ( umol / l ) : 0 . 072 - 19 . 966 salinity ( pps ) : 31 . 668 - 37 . 612 oxygen ( ml / l ) : 1 . 746 - 6 . 538 phosphate ( umol / l ) : 0 . 047 - 1 . 601 silicate ( umol / l ) : 0 . 756 - 35 . 349 graphical representation depth range ( m ) : 0 - 479 temperature range ( °c ) : 7 . 337 - 28 . 215 nitrate ( umol / l ) : 0 . 072 - 19 . 966 salinity ( pps ) : 31 . 668 - 37 . 612 oxygen ( ml / l ) : 1 . 746 - 6 . 538 phosphate ( umol / l ) : 0 . 047 - 1 . 601 silicate ( umol / l ) : 0 . 756 - 35 . 349 note : this information has not been validated . check this * note * . your feedback is most welcome .
depth range based on 1 specimen in 1 taxon . environmental ranges depth range ( m ) : 4 - 4 note : this information has not been validated . check this * note * . your feedback is most welcome .
sepkoski , jack ( 2002 ) .
a compendium of fossil marine animal genera ( chondrichthyes entry )
. bulletins of american paleontology 364 : 560 .
froese , rainer , and daniel pauly , eds . ( 2013 ) . species of dasyatis in fishbase . august 2013 version .
last , p . r . & white , w . t . ( 2013 ) : two new stingrays ( chondrichthyes : dasyatidae ) from the eastern indonesian archipelago . zootaxa , 3722 ( 1 ) : 1–21 .
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) : 27 - 28 . 3 , mean 27 . 6 ( based on 302 cells ) . phylogenetic diversity index ( ref .
bayesian length - weight : a = 0 . 00646 ( 0 . 00274 - 0 . 01522 ) , b = 3 . 11 ( 2 . 90 - 3 . 32 ) , in cm total length , based on lwr estimates for this ( sub ) family - body shape ( ref .
) : low , minimum population doubling time 4 . 5 - 14 years ( assuming fecundity < 100 ) .
some preliminary notes on surinam sting rays , including the description of a new species .
( boeseman , 1948 ) : in : database of modern sharks , rays and chimaeras , www . shark - references . com , world wide web electronic publication , version 07 / 2018
disc is narrowly projecting to snout , pelvic fins with long anterior margins . narrowly pointed falcate outer corners . upper surface dark brown , lower surface pale with darker margins and teeth as yellowish white
demersal ; brackish ; marine ; depth range 5 - 25 m ( ref .
host - parasite list / parasite - host list ( version : 01 . 04 . 2015 ) 544 pp , 5 , 37 mb new !
ecologically , stingrays are important components of aquatic food chains , consuming mollusks , crustaceans , tube anemones , amphipods , and small fish , while being preyed upon by a multitude of sharks , such as the white , tiger , and bull sharks , and even alligators in the case of freshwater species ( passarelli and piercy 2008 ) . while they provide some culinary value for humans , one of their chief values may be more internal—the wonder and beauty provided by their unique form , swimming behavior , and colors .
stingrays are members of the chondrichthyes or
cartilaginous fishes ,
a major class of jawed fish that includes the sharks , rays , and skates . members of chondrichthyes are characterized by skeletons made of rubbery cartilage rather than bone , as in the bony fishes . the chondrichthyans have jaws , paired fins , paired nostrils , scales , and two - chambered hearts . two subclasses of chondrichthyes are recognized , elasmobranchii ( sharks , rays , and skates ) and holocephali ( chimaera , sometimes called ghost sharks ) .
taxonomy for levels between elasmobranchii and genera is unsettled , with diverse taxonomies . for example , some classifications consider the sharks a sister group with the rays and skates , placing these two groups into different superorders , while other classifications place the rays and skates as a subsection of the sharks ( mceachran 2004 ) . that is , some view sharks and rays together forming a monophyletic group , and sharks without rays a paraphyletic group , while others see sharks sharing a common ancestor with rays and skates as sister groups ( nelson 2004 ) .
the same taxonomic diversity is apparent at the level of the family dasyatidae . dasyatidae is variously placed in the order rajiformes ( agbayani 2004 ) , or in the order myliobatiformes ( passarelli and piercy , 2008 ) . this is because in some classifications the order rajiformes is split into two or three orders , with myliobatiformes being an extra order and including the traditional rajiformes families of dasyatidae ( stingrays ) , gymnuridae ( butterfly rays ) , mobulidae ( manta rays ) , myliobatidae ( eagle rays ) , and others ( itis 2004 ) .
furthermore , what genera and families are included in dasyatidae vary with taxonomic scheme . nelson ( 1994 ) recognizes two subfamilies , dasyatinae ( stingrays or whiprays ) and potamotrygoninae ( river sitngrays ) , and he recognizes nine genera , as does agbayani ( 2004 ) . itis ( 2004 ) elevates the second subfamily of river stingrays ( which are the freshwater rays in south america ) to the family level as potamotrygonidae , recognizing six genera .
unless otherwise stated , this article will follow the narrower view of dasyatidae of itis ( 2004 ) , which will be equivalent to subfamily dasyatinae of nelson ( 1994 ) .
in stingrays , as with all rays in the traditional order rajiformes , the anterior edge of the pectoral fin , which is greatly enlarged , is attached to the side of the head anterior to the gill openings ( nelson 1994 ) . they also have ventral gill openings , and the eyes and spiracles are on the dorsal surface ( nelson 1994 ) . in addition , they lack an anal fin and lack a nictitating membrane with the cornea attached directly to the skin around the eyes ( nelson 1994 ) .
in members of dasyatidae—subfamily dasyatinae , in nelson 1994—the disc is less than 1 . 3 times as broad as it is long ( nelson 1994 ) . they lack a caudal fin and the tail is long , with the distance from the cloaca to the tip much longer than the breadth of the disc ( nelson 1994 ) .
dasyatids are common in tropical coastal waters throughout the world , and there are fresh water species in asia ( himantura sp . ) , africa , and florida ( dasyatis sabina ) . nelson ( 1994 ) reports that several tropical species of dasyatidae ( subfamily dasyatinae ) are known only from freshwater , and some marine species are found in brackish and freshwater on occasion .
their stinger is a razor - sharp , barbed , or serrated cartilaginous spine , which grows from the ray ' s whip - like tail ( like a fingernail ) , and can grow as long as 37 centimeters ( about 14 . 6 inches ) . on the underside of the spine are two grooves containing venom - secreting glandular tissue . the entire spine is covered with a thin layer of skin called the integumentary sheath , in which venom is concentrated ( meyer 1997 ) . the venom contains the enzymes 5 - nucleotidase and phosphodiesterase , which breakdown and kill cells ; and the neurotransmitter serotonin , which provokes smooth - muscle contractions ( layton 2008 ) . this venomous spine gives them their common name of stingrays ( a compound of
sting
and
ray
) , but the name can also be used to refer to any poisonous ray .
stingrays may also be called the
whip - tailed rays ,
though this usage is much less common .
a group or collection of stingrays is commonly referred to as a
fever
of stingrays .
the flattened bodies of stingrays allow them effective concealment in sand . smell and electro - receptors are used to locate prey , similar to those of sharks . some sting rays ' mouths contain two powerful , shell - crushing plates , while some species only have sucking mouth parts . rays settle on the bottom while feeding , sometimes leaving only their eyes and tail visible . coral reefs are favored feeding grounds and are usually shared with sharks during high tide .
mating season occurs in the winter . when a male is courting a female , he will follow her closely , biting at her pectoral disc . during mating , the male will go on top of the female ( his belly on her back ) and put one of his two claspers into her vent ( martin 2008 ) .
most rays are ovoviviparous , bearing live young in
litters
of five to ten . the female holds the embryos in the womb without a placenta . instead , the embryos absorb nutrients from a yolk sac , and after the sac is depleted , the mother provides uterine milk ( passarelli and piercy 2008 ) .
in addition to their ecological role in aquatic food chains , stingrays offer a number of values to humans , in terms of food , various products , and ecotourism .
the skin of the ray is rough and can be used as leather ( mceachran 2004 ) . the skin is used as an underlayer for the cord or leather wrap ( ito ) on japanese swords ( katanas ) due to its hard , rough texture that keeps the braided wrap from sliding on the handle during use . native american indians used the spines of stingrays for arrowheads , while groups in the indo - west pacific used them as war clubs ( mceachran 2004 ) .
many tahitian island resorts regularly offer guests the chance to
feed the stingrays and sharks .
this consists of taking a boat to the outer lagoon reefs then standing in waist - high water while habituated stingrays swarm around , pressing right up against a person seeking food .
while most dasyatids are relatively widespread and unlikely to be threatened , there are several species ( for example , taeniura meyeni , dasyatis colarensis , d . garouaensis , and d . laosensis ) where the conservation status is more problematic , leading to them being listed as vulnerable or endangered by iucn . the status of several other species are poorly known , leading to them being listed as data deficient .
himantura hortlei last , manjaji - matsumoto & kailola , 2006 . [ 1 ]
pacific chupare , himantura pacifica ( beebe & tee - van , 1941 ) .
white - edge freshwater whip ray , himantura signifer ( compagno & roberts , 1982 ) .
pastinachus solocirostris ( last , manjaji & yearsley , 2005 ) . [ 4 ]
↑ p . r . last , m . manjaji - matsumoto , and p . j . kailola , himantura hortlei n . sp . , a new species of whipray ( myliobatiformes : dasyatidae ) from irian jaya , indonesia , zootaxa 1239 ( 2006 ) : 19 - 34 . retrieved june 2 , 2008 .
↑ m . manjaji - matsumoto and p . j . last , himantura lobistoma , a new whipray ( rajiformes : dasyatidae ) from borneo , with comments on the status of dasyatis microphthalmus , ichthyological research 53 ( 3 ) ( 2006 ) : 291ff . retrieved june 2 , 2008 .
agbayani , e . 2004 . family dasyatidae : stingrays . in r . froese and d . pauly ( eds . ) , fishbase . retrieved june 2 , 2008 .
integrated taxonomic information system ( itis ) . 2003a . dasyatidae jordan , 1888 . itis taxonomic serial no . : 160946 . retrieved june 2 , 2008 .
integrated taxonomic information system ( itis ) . 2003b . rajiformes . itis taxonomic serial no . : 160806 . retrieved june 2 , 2008 .
integrated taxonomic information system ( itis ) . 2004 . myliobatiformes . itis taxonomic serial no . : 649685 . retrieved june 2 , 2008 .
layton , j . 2008 . how do stingrays kill ? how stuff works . retrieved june 2 , 2008 .
mceashran , j . d . 2004 . rajiformes . in b . grzimek , s . f . craig , d . a . thoney , n . schlager , and m . hutchins . grzimek ' s animal life encyclopedia , 2nd edition . detroit , mi : thomson / gale . isbn 0787657786 .
nelson , j . s . 1994 . fishes of the world , 3rd edition . new york : john wiley & sons . isbn 0471547131 .
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a long - snouted species of dasyatis with a broad , almost rounded disk . eyes and spiracle relatively small . tips of pectoral fins bluntly rounded . pre - orbital length much longer than distance between the spiracles ( > 35 % sl ) , with pronounced concave margins of snout . snout pointed and very long . the dorsal surface has a broad patch of medial denticles and a medial line of tubercles . additional denticles on the interorbital space are often present . pelvic fins very short but extremely broad in width , often extending beyond lateral disk margins . ventral finflap low but much more pronounced than dorsal finflap .
last , p . r . , naylor , g . j . p . , & manjaji - matsumoto , b . m . 2016 . a revised classification of the family dasyatidae ( chondrichthyes : myliobatiformes ) based on new morphological and molecular insights . zootaxa , 4139 ( 3 ) : 345 - 368 .
provisionally placed in the genus fontitrygon by last et al . ( 2016 ) with other large atlantic estuarine rays .
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 .
. between the long and narrow nostrils , there is a short and broad
skirt
of skin with a weakly fringed posterior margin . the small , bow - shaped mouth is surrounded by deep furrows and contains a row of five papillae across the floor , with the outermost pair tiny and set apart from the others . the teeth are small and arranged into pavement - like surfaces . there are five pairs of
the tail measures twice as long as the disc , and is broad and flattened at the base . on its upper surface is at least one , often two serrated stinging spines . past the spines , the tail quickly tapers to become whip - like and bears a well - developed keel above and a long , low fin fold beneath . there are wide patches of small
with flattened crowns between the eyes and over the middle of the back , along with a midline row of enlarged thorns that become progressively longer until they reach the base of the sting . aside from the thorns at the base , the tail is smooth . this species is yellowish to greenish brown above , lightening towards the disc margins and darkening past the tail spine , and white below . it grows to at least 93 cm ( 37 in ) across , and possibly reaches a width of 1 . 2 m ( 3 . 9 ft ) .
but recent observations have shown this is not the case . additional species records from the
and have sandy to muddy bottoms . this species is rarely found outside these sheltered areas , though it has been recorded to a depth of 28 m ( 92 ft ) in offshore waters . it inhabits marine and
as well as it has been known to swim upriver beyond the limit of high tide . surface water temperatures within its range vary from 24–29 °c ( 75–84 °f ) in the north to 17–23 °c ( 63–73 °f ) in the south .
sustained initially by yolk and later by histotroph (
uterine milk
) produced by the mother . females probably produce offspring every year .
the newborns measure around 11 cm ( 4 . 3 in ) across and 35 cm ( 14 in ) long .
and in hays inlet ; such fresh or brackish environments may serve as nurseries .
males mature at around 41 cm ( 16 in ) across and seven years of age , and females mature at around 63 cm ( 25 in ) across and 13 years of age .
this disparity in maturation size between the sexes is among the widest known for stingrays .
the maximum lifespan is estimated to be 16 years for males and 23 years for females .
although it is not commercially utilized , it faces a number of other threats . this species is captured incidentally by commercial bottom trawl and
mortality is exacerbated by the practice of
spiking
, in which the ray ' s cranium is pierced with a metal bar or sharpened stick so as to move it . it is also readily caught , and often killed , by
surveys in moreton bay have found fishing - related effects , such as embedded hooks and mutilated tails , in over 10 % of the population .
finally , this ray ' s reputation for damaging shellfish has led to persecution by commercial shellfish farmers .
( mpas ) are located within its range , but at present they lack adequate protection from fishing . as this ray remains locally abundant in hervey bay and parts of moreton bay , these areas may become important centers for preserving the species .
last , p . r . ; stevens , j . d . ( 2009 ) . sharks and rays of australia ( second ed . ) . harvard university press . pp . 435–436 . isbn 0674034112 .
last , p . r . ( 2002 ) .
freshwater and estuarine elasmobranchs of australia
. in fowler , s . l . , t . m . reed and f . a . dipper . elasmobranch biodiversity , conservation and management . iucn . pp . 185–193 . isbn 2831706505 .
ogilby , j . d . ( 25 august 1908 ) .
on new genera and species of fishes
. proceedings of the royal society of queensland 21 : 1–26 .
^ froese , rainer , and daniel pauly , eds . ( 2010 ) .
dasyatis fluviorum
in fishbase . january 2010 version .
pierce , s . j . ; scott - holland , t . b . ; bennett , m . b . ( april 2011 ) .
reexamination of the trypanorhynch cestode collections of a . e . shipley , j . hornell and t . southwell , with the erection of a new genus ,
— conservation status data deficient ( iucn 3 . 1 ) [ 1 ] …
— conservation status near threatened ( iucn 3 . 1 ) [ 1 ] …