rheocles is a genus of madagascar rainbowfish .

rheocles has a restricted distribution , being found only in certain forested freshwater habitats in the central and eastern highlands of madagascar including the nosivolo river .

the genus appears to feed almost exclusively on allochthonous material , primarily insects falling onto the water surface .

rheocles

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arkive species - rheocles ( rheocles vatosoa )
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rheocles is an exclusively freshwater genus of madagascan bedotiid ecologically restricted to heavily forested streams ( stiassny 1990 ) .
rheocles vatosoa begins to spawn in late october and early november and is believed to have an extended breeding season ( 2 ) . based on the reproductive behaviour of a closely - related species , rheocles alaotrensis , along with an absence of aquatic plants in its habitat , it is thought that rheocles vatosoa deposits its eggs in patches of coarse gravel ( 2 ) .
based on recent work , rheocles alaotrensis is now considered to be restricted to alaotra and the surrounded lakes and maningory system .
rheocles species belong to the family bedotiidae and are closely related to the madagascar rainbowfishes . many of the differences that separate the genera rheocles and bedotia are skeletal and are difficult for the average hobbyist to detect . externally , the presence of a bedotia notch on the premaxillae ( upper jaw ) of malagasy rainbowfish helps to readily distinguish bedotia from rheocles in all known species . cichlids of madagascar > >
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arkive species - katrana ( rheocles alaotrensis )
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arkive species - zono ( rheocles wrightae )
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a freshwater species , rheocles vatosoa occupies clear waters of both rapidly flowing rivers and small brooks , over gravel or coarse sand bottoms ( 2 ) .
rheocles wrightae is distributed along mangoro catchment in madagascar . a subpopulation is also found in the upper reaches of the lakato river ( ravelomanana unpublished data ) .
not much is known about the captive husbandry of rheocles species , which is both bad news and good news . this is bad news because not only are rheocles species hard to get hold of , but the little that we know about them shows that they can be finicky when it comes to captive care .
description of a new species of rheocles ( atherinomorpha , bedotiidae ) from the nosivolo tributary , mangoro river , eastern malagasy republic . american museum novitates ; no . 3031
this species is known from lac alaotra , upstream of maningory and betsiboka rivers , in madagascar . a recent ambatovy project study discovered that the rheocles alaotrensis occurring in mangoro system is a new species , and the rianila subpopulation is also a new species . therefore , rheocles alaotrensis is restricted to alaotra and the surrounded lakes and maningory system .
although there are no known specific conservation measures currently in place for rheocles vatosoa , the catchment of streams in the lokoho basin is now protected by the marojejy national park ( 1 ) .
males defend a small territory that is typically centered around a landmark , such as a rock or collection of mops . they display rapid up - down swimming motions when ripe females approach . rheocles species lay small sticky eggs on the aquarium substrate . unlike bedotia species that typically lay their eggs in tight clusters , rheocles species lay their eggs singly and prefer a firm substrate to spawning mops .
details - description of a new species of rheocles ( atherinomorpha , bedotiidae ) from the nosivolo tributary , mangoro river , eastern malagasy republic . american museum novitates ; no . 3031 - biodiversity heritage library
the type series and all available specimens of rheocles vatosoa have been collected in upper reaches of the lokoho river in the general vicinity of the town of andapa ( stiassny et al . 2002 ) .
very little information is available on the biology of rheocles vatosoa . its diet appears to be somewhat opportunistic , consisting of both terrestrial insects , likely to have fallen into the water from overhanging trees , and aquatic insect larvae ( 2 ) .
rheocles derhami only known from amboaboa and mangarahara rivers in the sofia drainage . recent surveys ( 2013 - 2014 ) only found one specimen in amboaboa near the marotandrano village . no other subpopulations are found elsewhere ( pers . obs . ) .
eggs hatch in six to eight days at temperatures near 80 degrees fahrenheit . rheocles fry are small and will have trouble consuming brine shrimp nauplii as their first food so have an infusoria culture or some vinegar eels for starting foods . keep in mind that rheocles fry are extremely fragile for the first few months of life , and attempting to move young ones to a rearing aquarium often leaves you with nothing to rear . it is best to move the parents and leave the fry where they hatch .
rheocles alaotrensis was caught in the middle of alaotra lake where the depth was about one metre . the water was coloured between red or yellow . the lake substrate was silt . it is found is forested and semi - forested streams and small lakes .
rheocles species grow to an average total length of 3 inches with larger individuals reaching close to 3¾ inches . two species — r . vatosoa and r . derhami — show constant sexual dichromatism while the other five species are monochromatic outside the reproductive season .
what the heck are silversides from madagascar , you might ask . well , these small sleek fishes belong to the genus rheocles and are found , for the most part , in cooler faster flowing waters around madagascar’s northern territories . however , just to make things difficult , paul loiselle , ph . d . , recently discovered a new species of rheocles in the far south near ft . dauphin . there are currently seven species recognized in this genus , which was first described in 1891 . killifish of madagascar > >
stiassny , m . l . j . ( 1990 ) notes on the anatomy and relationships of the bedotiid fishes of madagascar : with a taxonomic revision of the genus rheocles ( atherinomorpha , bedotiidae ) . american museum novitates , 2979 : 1 - 33 .
stiassny , m . l . j . , rodriguez , d . m . and loiselle , p . v . ( 2002 ) rheocles vatosoa , a new species of freshwater rainbowfish ( atherinomorpha : bedotiidae ) from the lokoho river basin in northeastern madagascar . cybium , 261 : 71 - 77 .
loiselle , p . v . and stiassny , m . l . j . ( 2003 ) rheocles , malagasy rainbowfish , aona . in : goodman , s . m . and benstead , j . p . ( eds . ) the natural history of madagascar . university of chicago press , chicago .
ty - book ti - description of a new species of rheocles ( atherinomorpha , bedotiidae ) from the nosivolo tributary , mangoro river , eastern malagasy republic . american museum novitates ; no . 3031 ur - urltoken py - 1992 au - reinthal , peter . au - stiassny , melanie l . j . er -
stiassny , m . l . j . and d . m . rodriguez , 2001 . rheocles derhami , a new species of freshwater rainbowfish ( atherinomorpha : bedotiidae ) from the ambomboa river in northeastern madagascar . ichthyol . explor . freshwat . 12 ( 2 ) : 97 - 104 . ( ref . 39832 )
throughout its range , rheocles vatosoa is found predominately in clear streams over gravel or coarse sand bottoms . such streams are characterized by soft , slightly acidic to moderately alkaline water , total and carbonate hardness value < 1°dh , electrical conductivity between 23 and 30µs / cm and ph values between 6 . 8 and 7 . 5 .
filtration was easily supplied with undergravel filter plates covered in small - diameter gravel and supplemented with air - driven sponge filters . this filtration was sufficient for 15 specimens in a 50 - gallon aquarium . i see no reason to forego canister or hang - on filters if that is your preference , and rheocles species might appreciate the increased flow rate .
malagasy silversides live in waters ranging from 5 . 0 to 8 . 5 ph , low hardness ( less than 3 dkh ) and cool temperatures usually lower than 73 degrees fahrenheit . analysis of gut contents shows that , like pachypanchax and bedotia species , rheocles species are somewhat opportunistic feeders that prey on both aquatic insects and terrestrial insects that fall into the water .
rheocles vatosoa is currently known only from the lokoho river in north - eastern madagascar , where it occurs in the upper and middle reaches of the main river channel in the general vicinity of the town of andapa ( 1 ) ( 2 ) ( 3 ) ( 4 ) . it typically occurs between 400 and 940 metres above sea level ( 2 ) ( 5 ) .
the second challenge with rheocles species is disease . like the malagasy cichlids , malagasy silversides are highly susceptible to ich ( ichthyophthirius multfiliis ) infection and it can be deadly if not caught in time . treatment with an over - the - counter ich medication ( malachite and formalin - based , if possible ) coupled with increased temperatures between 78 and 82 degrees does the trick .
in andreba village , the rheocles alaotrensis fishery is very important . they use mosquito nets as seine . significant quantities of this species go to ambatondrazaka , moramanga and antananarivo markets . the alaotra lake habitat loss is well studied by moreau ( 1977 ) . continued deforestation throughout its range is a threat . the species is also threatened by the alien invasive species of channidae and xiphophorus helleri .
justification : based on recent survey work this species is more widespread than previously hypothesized . the eoo is still less than 5 , 000 km² , it is known from four separate locations , and the habitat quality is declining , largely due to the impacts of deforestation . rheocles wrightae is therefore assessed as endangered . it should however be noted that taxonomic work is required to confirm the species range .
more worrisome is the rheocles susceptibility to a bloatlike condition , at least in wild - caught specimens . the founder population i worked with in denver developed bloat after one year in captivity . abdominal swelling with sudden listlessness defied both water parameters adjustment and pharmaceutical use and eventually caused 100 - percent mortality in the population . subsequent generations seem less prone to bloat and no definitive cause was ever identified .
rheocles alaotrensis males undergo a dramatic color change when coming into breeding condition , with unpaired fins becoming a deep red with the main body a dark , sooty black . i would hazard a guess that in the four other species that are normally monochromatic ( r . wrightae , r . pellegrini , r . sikorae and r . lateralis ) , a distinct change in coloration is associated with spawning .
@ book { bhl170907 , title = { description of a new species of rheocles ( atherinomorpha , bedotiidae ) from the nosivolo tributary , mangoro river , eastern malagasy republic . american museum novitates ; no . 3031 } , url = urltoken note = urltoken publisher = { } , author = { reinthal , peter . and stiassny , melanie l . j . } , year = { } , pages = { 0 } , }
rheocles alaotrensis , r . vatosoa and r . wrightae have all been kept in aquaria for varying lengths of time . the lake alaotra silverside ( r . alaotrensis ) was bred at the denver zoo for four generations before populations stopped breeding and began showing severe signs of physical malformation . during that time , we found that although our r . alaotrensis were collected in soft acidic waters with an average temperature of 66 degrees , they reproduced quite readily in our tap water ( ph of 7 . 2 , 8 dgh , 3 dkh ) with temperatures ranging from 75 to 82 degrees . we were never able to determine what caused the malformations and die off of our populations ; hypotheses included inbreeding depression and mercury poisoning of the founders .
dorsal spines ( total ) : 2 ; dorsal soft rays ( total ) : 14 - 19 ; anal spines : 1 ; anal soft rays : 15 - 21 ; vertebrae : 35 - 38 . rheocles derhami is readily distinguished from r . sikorae and r . wrightae by length of upper jaw ( 32 - 41 % hl versus 46 - 58 ) and absence of black pigmentation of genital papilla , from r . pellegrini by number of gill rakers on lower limb of first arch ( 9 - 10 versus 6 - 7 ) , from r . lateralis by caudal peduncle length ( 67 . 3 - 78 . 6 % sl versus 84 . 6 - 96 . 7 ) , and from r . alaotrensis by absence of chest and belly scales and paired predorsal scale rows ( ref . 39832 ) . in life males normally light grey , the second dorsal , anal and caudal fins are bright silvery blue , the throat region is orange - red , light grey females are not brightly colored ; preserved specimens are creamy yellow , scale rows in dorsal midline heavily pigmented and darkened ( ref . 39832 ) .
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a recent study done by the ambatovy project revealed that the rianila and mangoro subpopulations are genetically different from the alaotra subpopulation .
justification : the species has a restricted eoo ( 170 km² ) , is found in a single location threatened by the spread of invasive alien species , and suffers an ongoing decline and loss of habitat , primarily due to conversion to rice fields . the species is therefore assessed as endangered .
to make use of this information , please check the < terms of use > .
this species is still abundant in nosivolo tributaries and around anosibe an ' ala and mangabe . it is rarer in the upper reaches of the mangoro river to the north of moramanga ( ravelomanana , unpublished data ) .
the main threats are habitat loss and degradation through siltation caused by deforestation of a small remaining forested region ; and competition / predation from exotic invasive species .
some populations of this species are inside of different protected areas : corridor ankeniheny zahamena , couloir forestier anjjozorobe angavo , marolambo and nosivolo .
maturity : l m ? range ? - ? cm max length : 4 . 4 cm sl male / unsexed ; ( ref . 39832 )
reinthal , p . n . and m . l . j . stiassny , 1997 . revision of the madagascan genus ptychochromoides ( teleostei : cichlidae ) , with description of a new species . ichthyol . explor . freshwat . 7 ( 4 ) : 353 - 368 . ( ref . 26236 )
phylogenetic diversity index ( ref . 82805 ) : pd 50 = 0 . 5078 [ uniqueness , from 0 . 5 = low to 2 . 0 = high ] .
bayesian length - weight : a = 0 . 01000 ( 0 . 00244 - 0 . 04107 ) , b = 3 . 04 ( 2 . 81 - 3 . 27 ) , in cm total length , based on all lwr estimates for this body shape ( ref . 93245 ) .
trophic level ( ref . 69278 ) : 3 . 0 ±0 . 3 se ; based on size and trophs of closest relatives
resilience ( ref . 69278 ) : high , minimum population doubling time less than 15 months ( ) .
vulnerability ( ref . 59153 ) : low vulnerability ( 10 of 100 ) .
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africa : central east madagascar , lake alotra , maningory river system ; anjozorobe and in the tributaries of betsikiboka on the west slope of madagascar .
maturity : l m ? range ? - ? cm max length : 14 . 0 cm tl male / unsexed ; ( ref . 4114 )
maugé , l . a . , 1986 . atherinidae . p . 277 - 279 . in j . daget , j . - p . gosse and d . f . e . thys van den audenaerde ( eds . ) check - list of the freshwater fishes of africa ( cloffa ) . isnb , brussels ; mrac , tervuren ; and orstom , paris . vol . 2 . ( ref . 4114 )
bayesian length - weight : a = 0 . 01122 ( 0 . 00514 - 0 . 02450 ) , b = 3 . 04 ( 2 . 87 - 3 . 21 ) , in cm total length , based on all lwr estimates for this body shape ( ref . 93245 ) .
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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 .
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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 .
endangered b1ab ( i , ii , iii , v ) ver 3 . 1
justification : a recently described species known from the lokoho and andapa river basins , madagascar . even though the catchment of the streams in the lokoho basin is protected by the marojejy and anjanaharibe sud national parks , the restricted range ( eoo less than 5 , 000 km² ) , single location ( based on the threat from invasive alien species ) , and a continued decline in habitat extent and quality outside the national park ( mainly due to deforestation and rice farming ) , lead to an assessment of endangered for this species .
in forested streams within portions of its range , this species is still abundant . within the andapa basin and in andrakata river , this speces is now very rare .
fishery activity using mosquito net is common in the andapa rice fields . during the time period of our observations , this species was completely extirpated from this area ( ravelomanana , pers . obs . )
ongoing deforestation , mosquito net fishery activity and the presence of the exotic species : gambusia holbrooki , xiphophorus hellerii and channa maculata pose the principal threats to the long - term survival of r . vatosoa . the central part of the species range has also been converted into extensive areas of rice fields where this species is no longer present .
raminosoa , n . , randrianizahaisa , h . , rasoloariniaina , r & velosoa , j .
justification : this species is very restricted in the mandolotra river where it is only found in the clear running headwaters . it has an eoo of approximately 10 km² is found at a single location and suffers from the impacts of ongoing habitat decline and invasive species resulting in a continuing decline in the quality of habitat . the species is therefore assessed as critically endangered .
this species is known only from the mandolotra river affluent of nosivolo river in madagascar .
it was still abundant at the two places where it was found in 2007 ( ravelomanana pers comm . ) at the headwaters and confluence of the mandolotra and the nosivolo rivers .
loss of habitat quality following significant levels of deforestation . competition and predation from gambusia holbrooki and xiphophorus maculatus are also threats . overfishing with mosquito nets is also a threat .
raminosoa , n . , rasoloariniaina , r , ravelomanana , t . & velosoa , j .
justification : until the past decade , this species had not been collected since the 1930s , largely because its exact type locality was not known . in the past decade , additional specimens have been collected from the region of the type locality . however , there are little data available upon which to base statements about the quality of its habitat or the size of its population . it is assessed as data deficient .
the single known locality for r . pellegrini is given by nichols and lamonte ( 1931 ) as being
one day west of andapa .
the fish were collected by a . l . rand and p . a . dumont who were participants in the
archibold expedition
to the island ( stiassny , 1990 ) . subsequent specimens have been collected from this region in the past decade . it is endemic to madagascar .
subpopulations in the region of the type locality are extant and appear relatively stable .
deforestation and resulting habitat degradation in the region is a threat to this species .
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publication
> press w . h . , flannery b . p . , teukolsky s . a . and vetterling w . t . < br / > < strong > cyclic redundancy and other checksums < / strong > < br / > < a href =
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> numerical recipes in c 2nd ed . , pp896 - 902 , cambridge university press ( 1993 ) < / a > ) < / p >
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classified as vulnerable ( vu ) on the iucn red list ( 1 ) .
authenticated ( 17 / 08 / 10 ) by dr . paul v . loiselle , curator of freshwater fishes , new york aquarium . pvl2413 @ urltoken
kiener , a . ( 1963 ) poissons , pêche et pisciculture à madagascar . centre technique forestier tropical , nogent - sur - marne .
dr . paul v . loiselle curator of freshwater fishes new york aquarium surf ave . and west 8th st . brooklyn ny 11224 united states of america tel : ( 718 ) 265 - 3406 fax : ( 719 ) 265 - 3420 ploiselle @ urltoken
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raminosoa , n . , randrianizahaisa , h . , rasoloariniaina , r , ravelomanana , t . & velosoa , j .
this species is only known from a single location , a tributary of the sofia river in madagascar . the species was formerly abundant in this area as recorded by stiasnny et al . ( 1992 ) but surveys in 2013 ( tsilavina ravelomanana , brian zimmerman et al . ) found only one specimen despite extensive survey .
the species was formerly found in clear , pristine river habitat . it occurs in the upper part of the catchment where the water is relatively cool .
this species is facing a significant degree of habitat loss , which is the main cause of its decline . sedimentation changes the main river facies into shallow pools and runs . this kind of habitat is not suitable for this species especially when it is exposed to the sun , as the temperature climbs .
this species also faces huge overfishing pressure . local fishers use mosquito nets for fishing in the shallows and they practice poisoning in deep sections .
créée le 28 janvier 1976 , la société française d’ichtyologie s’est développée et internationalisée rapidement . malgré un changement de statut en 1988 , ses objectifs n’ont pas varié depuis 1976 . c’est pour répondre au quatrième point de ses objectifs – assurer la liaison entre ses membres par la diffusion d’une publication spécifique – que la revue cybium fut créée dès 1977 . la sfi a pris aussi l’initiative de publier ou d’aider à publier certains ouvrages qui ont fait l’objet ou non de numéros spéciaux de la revue .
cybium , éditée par la société française d’ichtyologie , publie des articles originaux , des articles de synthèse , des résumés de thèse , des analyses bibliographiques et des informations intéressant les membres de la société ou l’ensemble des ichtyologistes . les sujets traités doivent avoir un rapport direct avec l’ichtyologie générale , fondamentale ou appliquée , qu’il s’agisse de poissons d’eau douce ou de poissons marins , actuels ou fossiles .
the europeen society of marine biotechnology ( esmb ) and the tunisian association of bioressources valorization ( atvab ) will organize the international congress for marine biotechnology on 17th - . . . lire la suite
vous trouverez ci - dessous le le compte rendu des rif18 ainsi que le livre des résumés et quelques photos .
seminiferous tubule number and surface : validation of objective parameters to estimate reproduction activity of male european anchovy ( engraulis encrasicolus , l . )
physiculus sudanensis paulin , 1989 , a junior synonym of p . dalwigki kaup , 1858 ( teleostei , gadiformes , moridae ) , with a redescription of p . dalwigki
g . prestes - carneiro , p . béarez , k . dillenseger , t . yunoki
named for patrick de rham , director of the aquatic conservation network ( ref . 39832 )
maturity : l m ? range ? - ? cm max length : 5 . 0 cm sl male / unsexed ; ( ref . 39832 )
trophic level ( ref . 69278 ) : 3 . 2 ±0 . 40 se ; based on food items .
bonus content from the november 2009 fama magazine article fishes from the red island .
aquarium décor and lighting should attempt to mimic forested streams , so save the compact fluorescents and bubble curtains for other species . spawning mops or live plants can provide appropriate cover and subdued lighting is best for these somewhat skittish fishes .
the katrana is one of a family of small , colourful fish , the bedotiidae or madagascan rainbowfish , which inhabit the waters of madagascar . this species is one of the largest in the family , with an attractive yellow , pink and brown body ( 3 ) . male and female katranas can be distinguished by the colour of their fins ; while the male’s fins are bright red , those of the female have a pale rose colouration ( 4 ) .
the katrana is a schooling fish ( 5 ) , which feeds primarily on insects that have fallen into the water from the surrounding vegetation , as well as aquatic insect larvae ( 6 ) .
the eggs of the katrana are adhesive and attach to the stream banks and vegetation , preventing them from being swept away to unfavourable habitats . after spawning , the katrana leaves its eggs unguarded ( 7 ) ( 8 ) . the eggs hatch in 10 to 14 days , and the resulting fry ( young fish ) are capable of swimming and feeding as soon as they hatch ( 9 ) .
endemic to madagascar , the katrana is found in lake alaotra , the largest lake on the island , as well as the maningory and rianila river systems and tributaries of the betsiboka river ( 1 ) ( 2 ) ( 4 ) .
this freshwater species inhabits small rivers and streams that are clean , silt - free and well oxygenated , often with over - hanging vegetation ( 5 ) , as well as the open waters of lake alaotra ( 4 ) .
this small , colourful fish is threatened by an increase in human activities in the areas surrounding its habitat . large - scale slash - and - burn deforestation , such as that occurring around lake alaotra ( 10 ) , results in soil erosion and run - off into the surrounding rivers and streams . the increased silt suspended in the water disrupts water flow , smothers fish eggs , and generally creates an unfavourable environment ( 6 ) .
there is also an active fishery for this species in lake alaotra ( 4 ) . heavy fishing pressure has resulted in the katranas in the lake having a much smaller average length than that of populations inhabiting rivers ( 9 ) .
invasive fish species , introduced by humans to increase fishery productivity , are an ever - increasing problem to the native fishes of madagascar . it is not known how precisely these species displace the native fishes , but it is suspected a mix of predation and competition is responsible ( 6 ) .
although there are currently no specific conservation measures in place for the katrana in its natural environment , denver zoo is working on a captive breeding programme ( 11 ) and there are several broad - spectrum projects working on wetland preservation in the region ( 12 ) . while this species is currently doing much better than previously expected , like the other species in its family the katrana is still under considerable threat ( 1 ) .
maugé , l . a . ( 1986 ) atherinidae . in : daget , j . , gosse , j . p . and thys van den audenaerde , d . f . e . ( eds . ) check - list of the freshwater fishes of africa . volume 2 . orstom , paris and mrac , tervuren .
reinthal , p . j . , riseng , k . j . and sparks , j . s . ( 2003 ) water management issues in madagascar : biodiversity , conservation and deforestation . in : crisman , t . l . , chapman , l . j . , chapman , c . a . and kaufman , l . s . ( eds . ) conservation , ecology and management of african fresh waters . university press of florida , florida .
breder , c . m . and rosen , d . e . ( 1966 ) modes of reproduction in fishes . natural history press , new york .
mutschler , t . ( 2003 ) lac alaotra . in : goodman , s . m . and benstead , j . p . ( eds . ) the natural history of madagascar . university of chicago press , chicago .
andrianandrasana , h . t . , randriamahefasoa , j . , durbin , j . , lewis , r . e . and ratsimbazafy , j . h . ( 2005 ) participatory ecological monitoring of the alaotra wetlands in madagascar . biodiversityand conservation , 14 : 2757 - 2774 .
information on the zono is currently being researched and written and will appear here shortly .
classified as endangered ( en ) on the iucn red list ( 1 ) .
this information is awaiting authentication by a species expert , and will be updated as soon as possible . if you are able to help please contact : arkive @ urltoken


the emperor dragonfly or blue emperor ( anax imperator ) is a large species of hawker dragonfly of the family aeshnidae , averaging 78 millimetres ( 3.1 in ) in length .

emperor ( dragonfly )

a male emperor dragonfly hunting small insects above a pond . this photograph was taken in mid june .
the australian emperor dragonfly has two pair of wings which are about equal size . they are clean in colour . the construction is typical example of dragonfly ' s and
the australian emperor is a large , common , pale brown to yellow dragonfly with dark brown mottling and clear wings .
the australian emperor lives in urban areas , fresh water , forests , heath .
the common and widespread emperor dragonfly is larger with far more blue on the abdomen . the vagrant emperor is similar in appearance though it should be remembered that it is very unlikely this species will be recorded in shropshire . the lesser emperor has a more extensive patch of blue on the abdomen that extends further down the sides than in the vagrant emperor . the vagrant emperor also has brown not green eyes and has a distinctive pattern of wing cells which is diagnostic . the lesser emperor is also known to oviposit in tandem which is unusual in hawker dragonflies .
this dragonfly is a very large dragonfly . they never stop flying over the pond . they are common in brisbane .
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large ponds , lakes , canals and slow moving rivers are the preferred habitat of the emperor dragonfly , particular those with abundant submerged and floating vegetation .
following emergence , captive emperor dragonflies have been known to survive for up to 80 days .
the pictures above show the dragonfly rested on grasses and trees during late afternoon . the dragonfly rested there overnight until next morning .
the emperor dragonfly is classified as least concern ( lc ) on the iucn red list ( 1 ) . it is common and widespread in the uk ( 3 ) .
the bright blue male emperor dragonfly is extremely sharp sighted and is one of the fastest flying of all insects . the emperor dragonfly has remained unchanged for 230 million years . despite being able to beat its wings only 30 times a second ( ten times slower than a bee ) , it has no difficulty hunting down more highly evolved insect species .
the emperor dragonfly is not threatened at present , however many dragonflies are vulnerable to water pollution and loss of habitat by infilling of ponds , and drainage of water bodies ( 4 ) .
the larvae of the australian emperor are usually found on water plants and are active predators that stalk prey and grow quickly .
- deniss reeves , austrolestes - newsletter of australian dragonfly society , # 8 , 2003 .
habits : the male emperor dragonfly is almost continuously airborne , in search of a mate or prey that may stray into its territory . the dragonfly’s territory is always over a freshwater pond or lake . the defending dragonfly will attack the trespasser immediately by flying under him to force him up and away from the water . the green and brown female stays away from the water until she is ready to breed , so she is sighted less frequently .
related species : a subspecies of anax imperator occurs in southern africa . distribution : the emperor dragonfly is found in europe , the british isles , north africa , the middle east , and northwestern india . conservation : the dragonfly is extremely susceptible to the effects of water pollution and drainage . its future depends on the survival of clean , unpolluted ponds , lakes , and waterways .
the emperor dragonfly breeds in a range of aquatic habitats including large ponds , canals , slow - flowing rivers , lakes , flooded gravel pits , and dykes , but in all cases there must be a plentiful supply of marginal vegetation that emerges from the water ( 1 ) .
the bright unique colouring and patterns of the adults & aggressive behaviour of the males make this species very distinctive . only confusion could be with rare migrant lesser emperor .
during a sunny summer day , you will see the dragonfly flying over every piece of large flash waters in brisbane . it is usually the largest dragonfly on the water and will chase away any flying object on its path . the dragonfly is pale yellow in colour with grey pattern on the body . the costa , or the front edges of its wings are pale yellow .
the first picture above shows the australian emperor pair laying eggs in the plant under the water , still in tandem position . sometimes we saw the female dragonfly laying eggs alone . the female resembles male . the breeding sites are ponds and slow running water with thick vegetations . more information about reproduction please visit
all photos published on this site are copyright of the original photographer and are reproduced with their permission . all other content of this site is copyright of the british dragonfly society except where explicitly stated otherwise . the british dragonfly society is a registered charity , number 1168300 .
8 ) the flight of the dragonfly is so special that it has inspired engineers who dream of making robots that fly like dragonflies .
the coloration and markings distinguish this from all other shropshire species though two migrant species may cause confusion . the vagrant emperor is extremely rare , but the lesser emperor is being recorded with increasing frequency though not yet in shropshire . both these species are smaller with reduced areas of blue on the abdomen and lacking the striking apple green thorax . see the relevant species pages for more details .
10 ) nearly all of the dragonfly’s head is eye , so they have incredible vision that encompasses almost every angle except right behind them .
14 ) a dragonfly called the globe skinner has the longest migration of any insect—11 , 000 miles back and forth across the indian ocean .
there has been a huge upsurge in records of this distinctive dragonfly in our area since 1990 and it is now distributed widely throughout leicestershire & rutland .
this page contains information and pictures about yellow emperor dragonflies that we found in the brisbane area , queensland , australia . they are also known as yellow emperors . in new zealand they are known as baron dragonflies .
m ale anax imperator photo © david kitching 2006 female anax imperator photo © david kitching 2004 distribution map for emperor dragonfly large dot = proven breeding , medium dot = probable breeding , small dot = possible breeding open rectangle = pre 1980 records only red dots show tetrads in which species has only been recorded since 1991 or where breeding status has been raised since 1991 .
cham , s . 2007 field guide to the larvae and exuviae of british dragonflies volume 1 : dragonflies ( anisoptera ) the british dragonfly society : 76 pp .
food and feeding : the adult dragonfly is able to catch most of its prey while flying . it plucks insects out of the air with its legs . the dragonfly is rarely still , and its huge , multifaceted eyes enable it to detect prey up to 40 feet away . almost any flying insect is suitable prey . the dragonfly eats small insects even while it is flying but takes larger prey to a resting perch . the emperor dragonfly’s larvae also hunt . they propel themselves through their underwater habitat by expelling water rapidly from their intestines . their extendable jaws , armed with deadly hooks , enable the larvae to catch and kill such food as water lice and nymphs . the shovel like jaw of the larva is used to capture a variety of freshwater animals . the legs form a basket in which insects are caught in flight and then transferred to the jaws to be eaten .
mainly seen over ponds , canals or slow - flowing streams , this beautiful insect flies for long periods without resting , which makes it a difficult dragonfly to study .
the male circumnavigates its territory and chases off any other dragonfly that comes near . each pair of wings moves in a different motion , giving the impression of a helicopter .
11 ) dragonflies , which eat insects as adults , are a great control on the mosquito population . a single dragonfly can eat 30 to hundreds of mosquitoes per day .
the eggs develop in about 3 weeks , depending upon the temperature of the water . the larva , or nymph , that hatches is wingless and lives in the water . it molts ( sheds its skin ) ten to fifteen times during the 2 years it takes to mature . almost all of its growth occurs in summer months . in the last stage of development the larva crawls out of the water and dries its skin in the sun . as the skin splits , the adult dragonfly emerges . once its soft wings have hardened , it can fly . the adult dragonfly lives for only a few brief weeks . the lifecycle of the emperor dragonfly guarantees that its larvae hatch at the same time , allowing a better chance for the adults to breed successfully .
the australian emperor dragonfly spend most of the time flying , defending its territory and hunting for prey , seldom rest on a sunny day . in flight it appear yellowish . at the end of its abdomen there is the yellow spot as the ' tail light ' . the males aggressively defend large territories over the water . . its territory can be as large as 50 meters on a section of slow running water . if there is the intruder , it will always be driven away by a series of noisy air battles . the dragonfly usually has its patrol flight one meter about the water in quite a routine path within its territory .
the emperor dragonfly has a broad global distribution ; it is found in europe from portugal to germany in the north , and extends eastwards to central asia ( 1 ) . it is also known from north africa and the middle east ( 2 ) . in britain , it is fairly widespread in southern england and south wales , but becomes quite scarce in the north midlands , although there are signs that the species is currently extending northwards ( 1 ) .
special features of the emperor dragonfly : the larva has an extended jaw armed with hooks . it pushes them forward to catch and kill its prey . the male uses calipers at the tip of his abdomen to grip the female’s thorax . the male transfers sperm from the tip of his abdomen to accessory sexual organs . the female then fertilizes the eggs . the copulation wheel : the female arches her body under the male to mate . they may fly in tandem while they are mating .
unless there have been any recent publications , courtship in dragonfly species only seems to have been described for a few species of libellulid dragonfly ( chasers , skimmers , darters etc ) , and seems to be very brief , consisting of little more than a male approaching a female , indicating his desire to mate , and perhaps showing off potential ovipositing sites within his territory . the female then indicates receptiveness , or leaves !
britain’s largest , heaviest and most impressive dragonfly . an early summer species . the brightly coloured turquoise and apple green males coupled with their aggressive territorial behaviour make this one of most well known and easily recognisable dragonflies .
visit any decent sized pond in early summer and you will probably encounter a male emperor patrolling it . they are very territorial and will chase other males and investigate other species . will fly away from water however to hunt . females are often visible laying eggs on floating vegetation and will do so alone .
did you know : dragonflies always rest with their wings spread open . dragonflies and their larvae are a popular food in some asian countries . there are over 30 , 000 facets in a dragonfly’s eye . very few birds can outfly and hunt down dragonflies . the fast flying , agile hobby is a match . the dragonfly’s front and hind wings beat alternately , not together , as with most insects . this gives them better flight control .
this common and familiar dragonfly in europe is nevertheless a comparatively recent colonist from africa , and still rapidly expanding its range northwards ( dijksta & lewington , 2006 ) . in the uk , it is absent from upland areas .
3 ) there are more than 5 , 000 known species of dragonflies , all of which ( along with damselflies ) belong to the order odonata , which means “toothed one” in greek and refers to the dragonfly’s serrated teeth .
most of the odonate behaviour that you will observe if you sit quietly by a pond or stream in summer is sexual in nature . most male dragonflies establish a territory – usually near a suitable site for the female to lay her eggs . the male defends the territory against other intruding males while waiting for a female to fly by . some species just perch and wait for this to happen ; others patrol the area for long periods . in hong kong , members of the aeshnidae family , such as the fiery emperor and the pale - spotted emperor , are particularly impressive as they patrol over ponds and streams , rarely coming down to rest .
we watched a female emperor ovipositing in a small pond . her mate was patrolling above , and caught a small butterfly . still in flight , the wings dropped off , and he then found the female , who flew up and took the food from him . she landed on a weed in the water , and sat eating .
the lesser emperor was first recorded in gloucestershire in 1996 and exuvia were found in cornwall in 1999 proving breeding had been successful ( cham et al . , 2014 ) . since the gloucestershire record this species had been recorded in worcestershire , cheshire and staffordshire and finally just last year in shropshire . definitely a rare migrant but always a possibility !
12 ) hundreds of dragonflies of different species will gather in swarms , either for feeding or migration . little is known about this behavior , but the dragonfly swarm project is collecting reports on swarms to better understand the behavior . ( report a swarm here . )
the profile of dragonflies has been raised in recent years , and many landowners build ponds in order to encourage them ( 4 ) . the british dragonfly society aims ' to promote and encourage the study and conservation of dragonflies and their natural habitats , especially in the united kingdom ' ( 6 ) .
naturewatch : the emperor dragonfly is usually recognizable by its large size . the male has a deep blue abdomen , divided by a central back stripe . its head is green . at close range it can be identified by the distinctive rounded inside edges of the hind wings . the female is green and brown and is much less conspicuous than the male . during summer the adult male patrols its territory – weedy ponds and lakes . it usually flies 6 - 20 feet above the water . when it does rest , it perches briefly on the edge of a reed bed or in a tree . adults can be found near any stretch of unpolluted fresh water in their range . larvae emerge from the water as early as may .
5 ) at the end of its larval stage , the dragonfly crawls out of the water , then its exoskeleton cracks open and releases the insect’s abdomen , which had been packed in like a telescope . its four wings come out , and they dry and harden over the next several hours to days .
dragonflies undergo a type of development known as incomplete metamorphosis in which the aquatic larvae ( sometime called nymphs ) undergo a series of moults ; the stages between moults are known as instars or ' stadia ' ( 4 ) . after hatching from eggs , the larvae develop quickly through the summer ; they enter their final instar during the autumn of the following year , and then enter ' diapause ' , a form of hibernation , before emerging as adults early the next summer ( 2 ) . in the first few instars , the larvae swim by undulating the body from side - to - side ; later on they develop a system of jet - propulsion which enables them to easily escape from predators such as water bugs , fish , other dragonfly larvae and beetles . the larvae of the emperor dragonfly are themselves voracious predators , armed with fearsome mouthparts known as a ' mask ' ; the mask is normally tucked under the head , but is rapidly extended in under 25 milliseconds ( 4 ) , piercing prey as large as small fish ( 2 ) .
13 ) scientists have tracked migratory dragonflies by attaching tiny transmitters to wings with a combination of eyelash adhesive and superglue . they found that green darners from new jersey traveled only every third day and an average of 7 . 5 miles per day ( though one dragonfly traveled 100 miles in a single day ) .
with just a handful of records prior to 1980 and similarly few in the succeeding decade , this is another species that can be considered a recent colonist to vc 55 . there has been a huge upsurge in records of this distinctive dragonfly since 1990 and it is now distributed widely through vc 55 in suitable habitat .
britain ' s bulkiest dragonfly . its bright colours and active habit make it very obvious when hunting over medium to large water bodies . it rarely settles , even eating its prey in flight . both sexes have a bright , apple - green thorax and green or blue eyes . the costa is bright yellow . they often fly with the rear of the abdomen bent slightly downwards .
while the adults are conspicuous , the larvae are little known to most of us . that is because they are aquatic creatures , living below the surface in freshwater streams and pools . they are generally dull , prehistoric - looking creatures – a far cry from the flaming adults . the following account focuses on the adults and attempts to briefly explain some of the dragonfly behaviour that an interested observer might be witness to in the summer months in hong kong .
freshly emerged dragonflies are ghost - like . their wings are shiny , their bodies lacking in pigments . it can take up to two weeks for a dragonfly to reach sexual maturity , during which time there is a transition to adult coloration . subadult coloration can be different from that of the mature adult , and can lead to difficulties of identification . in general , adult males are easier to identify than females and subadults as many of them are distinctive .
a large , robust , long - bodied dragonfly with a ' waisted ' appearance to the abdomen , which is longer than the hindwing . the eyes range from green to blue , with yellow to green undersides . animals have a plain green thorax and , in males , a light blue abdomen ( except for the first segment , which is usually green ) with a broad black dorsal stripe . the intensity of the blue colouration varies with weather conditions , becoming paler in cooler weather .
this is the largest dragonfly found in the uk and indeed shropshire . apart from a green segment 1 , the abdomen is mostly bright blue with a distinctive broad black dorsal line running from segment 2 - 10 . the thorax is apple green and has no antehumeral stripes or any noticeable side stripes . just in front of the wings are 2 triangular blue spots . the wings are clear with a yellow costa and long narrow brown pterostigma . the eyes are blue green and the legs black apart from some reddish brown on the femur .
the larvae of most species simply climb up the stems of emergent plants . some , however , crawl away from the water to find a suitable site to metamorphose into an adult – some even climb high into trees . once a site is found , the dragonfly slowly emerges , which can take 2 - 3 hours in dragonflies , an hour in damselflies . the shed larval skin ( known as an exuvia ) is left in place ; a good place to look for these exuviae is the water - lily pond at the outdoor study centre in tai po kau .
lifecycle : most of the dragonfly’s life is spent underwater as larva . it emerges as a winged adult for a few weeks a year to mate and lay eggs . usually mating takes place in the high branches of a tree along the pond’s bank , but sometimes it will occur in the air . the male pursues the female until he is able to settle on her back . the mating procedure is known as the “copulation wheel . ” the female fertilizes the eggs , then uses her ovipostor ( a special egg laying organ ) to lay them . to protect her eggs from being eaten by fish , she places them into slits that she has cut into stems of pondweed .
larva : a very large , elongate dragonfly larva , with a torpedo - like body and large , round eyes characterised by eye length much greater than width . the rear margin of the head is straight , and the head as a whole has a roughly circular appearance . the labium is three and a half to four times as long as wide . dorsal spines are present on the seventh and eighth abdominal segments , but there is no spine on the sixth segment . early - stage ( first year ) larvae are banded in black and white , colouration that is lost with age . this may be an adaptation that camouflages them against older larvae of the same species by imitating the effects of incident light near the water surface .
hi all , we were out with our son , daughter in law , and 6 year old grandson today . our grandson loves catching insects , crickets , grasshoppers etc . after studying them in his proper trap , he releases them again . whilst out , we saw various butterflies , and a couple of dragonflies . now , to ask the question . have any of you observed this behaviour ? we watched a female emperor ovipositing in a small pond . her mate was patrolling above , and caught a small butterfly . still in flight , the wings dropped off , and he then found the female , who flew up and took the food from him . she landed on a weed in the water , and sat eating . this all took place over some 20 minutes or so , much to the delight of all watching , especially our grandson , who was the quietest i have known him to be for such a long time . no decent pics of this action , despite many attempts , sorry . pics below of some other sightings . hope you like them .
after diapause , final instar larvae leave the water and crawl up vegetation . the adult emerges , leaving the discarded skin of the nymph attached to the plant ( 5 ) . the new adults undergo a period of feeding and maturation before starting to reproduce ( 4 ) . males set up territories , which they defend fiercely against other males ; they fly rapidly at two to six metres over the water , and very rarely come to a rest . during mating , males and females form a typical ' wheel ' mating posture , in which the male grabs the female behind her head using the claspers at the tip of his abdomen . after mating the female lays her eggs in floating vegetation , keeping low to avoid encounters with territorial males ( 2 ) .
you can view distribution information for this species at the national biodiversity network atlas .
there may be further information about this species available via the national biodiversity network atlas .
this information is awaiting authentication by a species expert , and will be updated as soon as possible . if you are able to help please contact : arkive @ urltoken
mcgeeny , a . ( 1986 ) a complete guide to british dragonflies . jonathan cape , london .
sterry , p . ( 1997 ) complete british wildlife photo guide . harper collins publishers , london .
o ' toole , c . ( 2002 ) the new encyclopedia of insects and their allies . oxford university press , oxford
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thank you for taking the time to provide feedback on the iucn red list of threatened species website , we are grateful for your input .
schorr , m . and paulson , d . 2013 . world odonata list . tacoma , washington , usa available at : urltoken . ( accessed : 20 november 2013 ) .
justification : anax imperator is a widespread species with no major threats worldwide and it is therefore assessed as least concern .
anax imperator is known from the whole africa to most of europe , the arabian peninsula and southwest and central asia . within india it is present in west bengal ( kolkata district ) , uttarakhand , maharashtra and tamil nadu . this species is presently expanding to the north due to the global warming and has been found in the southern part of sweden up to uppsala . in the british isles , its northern limit shifted by 80 km to the north so that now this species is known from scotland .
anax imperator breeds in any kind of standing and slow running waters bordered with rushes and weeds . it is a familiar species on all open waters , where males patrol and hawk restless over their territory and exclude their congeners . males most generally do not accompany the female during oviposition .
there are no threats at the global scale , although local declines may occur due to habitat destruction and water pollution .
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female : green abdomen , similarly marked , which may become blue in warm weather .
mostly associated with large , well vegetated ponds and lakes , but may be found over canals and slow moving rivers . the female lays her eggs , alone , in floating pondweed .
widespread in southern england and southern wales ; increasing its range northwards . recently appeared in ireland .
could perhaps be confused with other hawkers , but the large size and drooping abdomen ( in flight ) help identification .
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this is one of europe ' s largest dragonflies . the male is easy to identify with its apple green thorax and bright blue abdomen and blue eyes . the female is mostly green and also has the apple green thorax .
widespread but not common in england south of the humber and wales , little recorded elsewhere in britain .
eduard solà added the catalan common name
espiadimonis
to
anax imperator leach 1815
.
kari pihlaviita added the finnish common name
keisarikorento
to
anax imperator leach 1815
.
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the largest of the hawker dragonflies found in britain , this is a common species in southern england and wales .
the male ( below ) has a bright blue body , while the female , seen above laying eggs on emergent vegetation , has a greenish tinge , becoming gradually bluer when old .
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in profile view , there is a black marking at the base of each segment . immature males and females typically have a green ( sometimes brown in immatures ) abdomen , with a distinct thin yellow ring at the base of the second abdominal segment only in newly - emerged individuals , becoming green with age . the dorsal midline is often more brownish than black in females and tenerals . in both sexes , the costa ( leading edge of the wing ) is yellow , and the pterostigma brown . the wing itself is otherwise clear , but can become brownish in older females . the frons is marked with a black pentagon at the base , and there is a blue bar in front of this marking . some females have a blue abdomen ; they can be distinguished from males by two triangular blue markings on top of the thorax , just in front of the wings .
this is a species of still and occasionally slow - flowing waters , most often encountered around larger , well - vegetated waterbodies . it is known to colonise newly - formed pond , and is able to tolerate brackish conditions . larvae inhabit pondweed .
males of this fast - flying species patrol open areas of the waterbody , often higher and further from shore than related species . when they come into land , individuals typically rest vertically , low down in vegetation . in flight , the animal may hold its abdomen so that it curves downwards . animals are strongly territorial and will chase off smaller rivals , including members of other species with a similar appearance .
emperors will typically eat prey on the wing , but large prey items , such as large butterflies , dragonflies and similarly - sized insects , will often be consumed from a perch .
larvae are active predators that respond rapidly to movement and use their well - developed eyes to track prey . they are typically well - camouflaged within vegetation , clasping twigs or stems close to the water surface . unusually , they have been known to hunt in open water , using jet propulsion to pursue prey .
breeding behaviour : in contrast to other european emperors ( genus anax ) , females lay eggs alone , ovipositing directly into floating vegetation , including deadwood , away from shore . this exposed situation makes animals highly visible compared with related species .
emergence : emergence takes place between april and september ; in the uk , the peak emergence period is from may to july . larvae often emerge synchronously following a sequence of warm nights , and will typically select an emergence support a day or more in advance of moulting . during this period , animals may travel some distance from water , usually within 6 m but as far as 30 m has been recorded . larvae may climb up to 5 m into trees in preparation for emergence . emergence itself takes around three hours ; once the wings have fully expanded and are ready for use , animals may then wait for suitable early morning light levels before taking off , whirring their wings to increase their body temperature sufficiently for take - off in cool conditions . if conditions are particularly poor , partially - moulted larvae may actually return to water to reduce predation risk on land during the day , before re - emerging the following evening .
flight season : highly dependent on location , with north african populations flying from march until december . in northern europe , animals are most abundant from june to august .
life cycle : eggs hatch three weeks after being laid . in contrast to most members of the genus anax , at least in the uk , development follows immediately from oviposition with no intervening period of dormancy . larval development takes either one or two years , partially depending on when eggs were laid . following emergence , maturation takes between a week and 12 days in males , 13 - 16 days in females .
dijkstra , k - d . b . and lewington , r . 2006 field guide to the dragonflies of britain and europe british wildlife publishing : 320 pp
female , blue form , ovipositing . note the yellow costa , thick mid - dorsal line and the green of the thorax and first abdominal segment . unusually , this female exhibits blue triangular marks in front of the forewing , a feature typical of males , but the animal ' s behaviour identifies its sex .
all north africa and europe north to denmark on the mainland , and through southern britain and ireland populations become scarcer and more scattered in the north of this range and inland from the coast in ireland . in east africa . the species occurs south as far as zimbabwe and madagascar .
is carried near the wing tip . the main veins and the crossveins form the wing venation pattern . the venation patterns are different in different species . the
dijkstra , k . d . & suhling , f . ( odonata red list authority ) .
justification : regional assessment : the species is listed as least concern in view of its wide distribution , and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category .
eastern africa distribution : the species is common and widespread in kenya , tanzania , uganda , malawi , and assumed from burundi . global distribution : the species is widespread in africa and eurasia .
the body is dull green with a similar dark dorsal stripe extending along the abdomen . the eyes are green .
as the name suggests these large hawkers are top in the pecking order and the males will defend territory aggressively . the males are relentless fliers , only perching occasionally , and the male in flight is quite distinctive holding the abdomen bent slightly downward . copulation takes place a short distance from the waters edge whilst perched on a shrub or tree . the female then oviposits alone into submerged vegetation .
mostly found on well vegetated standing water habitats such as ponds , lakes , canals and large ditches , but also on slow flowing rivers . known to be a pioneer species often seen at new ponds .
numerous standing water sites across shropshire such as dudmaston estate , shropshire hills discovery centre at craven arms , attingham park , severn valley country park .
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key facts : sizes : length : adult , 3 in . ; larvae , 2in . wingspan : 4 in . coloration : adult male ; enable blue body with central black stripe and green head ; adult female : green head and greenish body . wings : 2 pairs , moved independently
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i have never heard of anything like this before , but will check some literature and see if i can find any reference to anything similar .
i would suspect that this was more likely to be theft of food rather than a deliberate feeding of the female by the male .
thanks roy . the male deffo was looking for the female before shec nabbed the food , so i assumed she was meant to take it . be interested in what you manage to find on your research . appreciated .
and i took my future wife out for a
chinese
on our first date . lol .
the male deffo was looking for the female before shec nabbed the food , so i assumed she was meant to take it .
similar brief courtship displays have also been described for a number of damselfly species , including the demoiselles found in the uk .
in most cases males of both dragonflies and damselflies simply try and grab females , which may indicate that they are not receptive for mating by bending their abdomen either up or down . if a male does manage to ' grab ' a female , he will then try and coax her to mate by bending his abdomen forward - although if the female is not receptive mating will not occur because she also needs to bend her abdomen forward if the mating wheel is to be formed .
thanks for the info roy , appreciated . when the female was given , ( stole ) the butterfly , she sat eating it on a leaf in the pond . the male continued patrolling , and attempting to catch other butterflies , unsuccessfully . he didn ' t venture far from the pond , so the prey got away . i was surprised at this , cos they , as you know , are very fast . it almost seemed he didn ' t want to let her out of his sight . i would have stayed longer . but our grandson wanted to go to the playground . cheers , steve .
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are a bright sky - turquoise blue colour with an irregular dark line down the centre of its abdomen . this bright colour will fade in cool conditions . the thorax is bright apple green , easily viewed from the side . eyes and face are bright blue . tends to droop its abdomen in flight , slightly banana shaped .
resemble pale females , with pale brown markings on the abdomen , green thorax and yellow - green eyes .
resemble the males with identical markings , the colour of the abdomen is green , the central line dark brown . however , in warm conditions the abdomen will become blue resembling a male . thorax is apple green . eyes are yellow - green but can also be blue .
resemble mature females with more muted drab colours . thorax is pale green and eyes pale yellow - brown .
mostly associated with large , well vegetated ponds and lakes , but may be found over canals and slow moving rivers . common in garden ponds .
very common in southern and central england and south wales . slowly spreading northwards and westwards . common and widespread in dorset .
main flight period is may to september , peaking between mid june to mid august .
flying insects are usually annoying . mosquitoes bite you , leaving itchy red welts . bees and wasps sting . flies are just disgusting . but there’s something magical about dragonflies .
1 ) dragonflies were some of the first winged insects to evolve , some 300 million years ago . modern dragonflies have wingspans of only two to five inches , but fossil dragonflies have been found with wingspans of up to two feet .
2 ) some scientists theorize that high oxygen levels during the paleozoic era allowed dragonflies to grow to monster size .
4 ) in their larval stage , which can last up to two years , dragonflies are aquatic and eat just about anything—tadpoles , mosquitoes , fish , other insect larvae and even each other .
6 ) dragonflies are expert fliers . they can fly straight up and down , hover like a helicopter and even mate mid - air . if they can’t fly , they’ll starve because they only eat prey they catch while flying .
7 ) dragonflies catch their insect prey by grabbing it with their feet . they’re so efficient in their hunting that , in one harvard university study , the dragonflies caught 90 to 95 percent of the prey released into their enclosure .
9 ) some adult dragonflies live for only a few weeks while others live up to a year .
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as the line from hopkins’s poem attests to , dragonflies can be strikingly colourful and conspicuous creatures . they belong to the order of insects known as odonota .
different species of odonates worldwide , roughly equally divided between dragonflies and damselflies . 116 species have been recorded in hong kong .
the larval stage of odonates can last for several years . the adult stage , in contrast , is often a few brief weeks . during those weeks the adult has to survive and breed . unlike butterflies , dragonflies lack a pupal stage in their development . in the final stage of larval development , when the adult is ready to emerge , the larva has to make the transition from the water to the land .
when a male comes upon a willing female , there is a pre - copulatory phase where the pair flies or perches “in tandem” . in this position , the male grasps the female ( behind the head in dragonflies , on the upper thorax in damselflies ) with the claspers situated at the tip of his abdomen . this deters other males from trying to copulate with the female .
copulation usually follows within a few minutes of the tandem position being assumed . for this to occur , the male and female take up what is called the “wheel position” . the reason for this is that the male has two separate sets of sexual organs . the primary sexual organ consists of sperm - producing testes located near the tip of the abdomen ( in the ninth abdominal segment , to be exact ) . the secondary sexual organ ( the penis ) is located under the second and third abdominal segments . before copulation , and usually while the pair are in the tandem position , the male bends his abdomen so that sperm is transferred from the primary sexual organ to the secondary sexual organ . the female then curves her abdomen so her genitalia located at the tip of the abdomen can connect with the male’s penis . the amount of time spent in sexual union varies from species to species , and can be from a few seconds to several hours .
the body is brown with a bright blue saddle on segments 2 - 3 . a black line runs from segment 3 down the dorsal surface of the abdomen and a yellow basal ring is visible on segment 2 . the thorax is completely brown and the eyes are green . the wings have a yellow costa and a general yellow suffusion . the pterostigma are yellow - brown .
very similar to the male but the abdomen is duller and the black dorsal line extends clearly on to segment 2 . a yellow band is visible at the base of segment 2 as in the male . the colour of the abdomen may vary with some females being more blue .
unusually for hawker species , the male and female remain in tandem whilst eggs are laid into floating vegetation ( brooks & cham , 2014 ) .
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