ponticola gorlap , or the caspian bighead goby , is a species of goby , a benthic fish native to the caspian sea basin .

it is widespread in lower parts of many rivers in iran , and also found in azerbaijan and turkmenistan .

in russia , it occurred in the lowest part of the volga river up to astrakhan until 1977 , but has thereafter spread upstream .

in 2000 it was recorded as being established in the ivankovo and rybinsk reservoirs in the moscow region , and already invaded the don drainage by way of the volga-don canal in 1972 .

this species occurs in sheltered environments , such as inshore fresh or brackish waters of estuaries , lagoons , lakes and large rivers , where it prefers habitats with a well vegetated rock or firmly packed sand substrate .

it can reach a length of 20 centimetres ( 7.9 in ) sl , and a common size is 12 centimetres ( 4.7 in ) sl .

ponticola gorlap

the following term was not found in genome : ponticola gorlap [ orgn ] .
( of neogobius gorlap iljin , 1949 ) froese , r . & d . pauly ( editors ) . ( 2018 ) . fishbase . world wide web electronic publication . , available online at urltoken [ details ]
( of neogobius kessleri gorlap iljin , 1949 ) froese , r . & d . pauly ( editors ) . ( 2018 ) . fishbase . world wide web electronic publication . , available online at urltoken [ details ]
the sea breams or porgies are found in the atlantic , indian and pacific oceans and comprise about 36 genera and about 130 species ( nelson , 2006 ; eschmeyer and fong , 2011 ) . some commonly enter estuaries and penetrate up rivers . maximum length is about 1 . 2 m .
this family is characterised by a groove in the distal end of the premaxilla which accommodates the maxilla ; the body is oblong to ovate and is compressed ; the head is large with a steep upper profile ; the preopercle margin is smooth ; scales are weakly ctenoid , moderate in size and extend on to the cheeks and operculum ; teeth are conical to incisiform and molar teeth are found in some at the rear of the jaw ; there are no teeth on the vomer , palatines or tongue ; the dorsal fin is continuous with an anterior spiny portion and a soft - rayed posterior portion about equal in size ; with 10 - 13 spines and 10 - 15 soft rays respectively ; spines fold into a groove ; the anal fin has 3 spines ( the second the largest ) and 8 - 14 soft rays ; branchiostegal rays 5 - 6 ; branchiostegal rays 5 - 6 ; and lateral line not continued onto the caudal fin but with enlarged scales near the head .
many species in this family are hermaphrodites with male and female sex organs developing simultaneously , changing sex from male to female ( protandry ) , or from female to male ( protogyny ) . these fishes are often important as food or sought by anglers . young fish may very different in colour to adults , usually being more vividly coloured with distinctive patterns . most species are marine ( see marine list in checklists in the
) but a few enter fresh water and penetrate a considerable distance from the sea including one species in iran .
members of this genus have a compressed and moderately deep body , 4 - 6 enlarged incisiform teeth at the front of the jaws followed by 3 - 4 rows of molars , the second anal fin spine is longer than the third , there is a scaly sheath at the base of the dorsal and anal soft fins , and moderate - sized scales . iwatsuki and heemstra ( 2010 ) revised the genus in the western indian ocean .
شانك ( = shanak ) , شانك زردباله ( = shanak - e zardbaleh or yellowfin shanak ) .
[ shanak , shaghoom , shaam , sha ' m , shaem , sheim or sha - om in arabic ; yellow - finned porgy or seabream , yellow - finned black porgy , japanese silver bream ] .
al - hassan ( 1990 ) found differences in two meristic characters ( pectoral and dorsal fin ray counts ) but no differences in electrophoretic characters between populations from the shatt al arab and khor al zubair areas of southern iraq . he concludes that there is only one stock of this species in southern iraq as meristic variation may reflect environmental conditions .
this species is the only sparid member recorded from iranian freshwaters and is recognised by the dorsal fin spines alternately thick and thin and the colour pattern .
upper profile of head steep and convex back to above the posterior eye margin . the head bulges over the eye . dorsal fin spines 11 - 13 , soft rays 9 - 13 . anal fin with 3 spines , the second much stronger and wider than the third , and 8 - 9 soft rays . pectoral fin branched rays 10 - 16 . there is a strong spine in the pelvic fin and a well - developed axillary scale . lateral line scales 41 - 46 , or 48 - 50 , or up to 55 depending probably on differing counting methods . the scales are vertical ovals with the anterior margin wavy where radii intersect . they have very fine circuli , moderate numbers of posterior radii , a subcentral posterior focus , and ctenii on the central part of the posterior margin extending inwards towards the focus . four or five series of preopercular scales . the first pelvic fin ray is elongated as a small filament . there is a strong pelvic axillary scale . there are 3 - 4 scale rows sheathing the dorsal and anal fin bases . there are 4 - 6 compressed teeth in front of each jaw followed by 3 - 5 rows of molar teeth . the chromosome number is 2n = 48 ( klinkhardt
meristic values for iranian specimens are : - dorsal fin spines 12 , soft rays 10 , anal fin spines 3 , soft rays 8 , pectoral fin branched rays 13 , scales mostly lost .
this species is a protandrous hermaphrodite , being male early in its life and then becoming female later . catches will include males , females and hermaphrodites , e . g . in abu - hakima ' s ( 1984a ) study in kuwait , there were 326 males , 343 females and 41 hermaphrodites .
overall colour is a silvery - grey or silvery - white with the back darker and the belly yellowish . scales each have a dark , brownish to golden spot at the base which line up to form apparent stripes along the flank . there is a dark blotch at the upper corner of the gill opening , on both the body and gill cover . there is a dark band over the head between the eyes and the edge of the operculum is dark . dorsal fin spines are white and the membranes are grey , with dark margins between the spine tips . the soft dorsal fin is dark grey with a light orange tinge . there is a small back spot at the pectoral fin base and the fin is mostly hyaline with a light orange tinge . the anal and pelvic fins are a light yellowish - brown . the caudal fin is dark grey on the upper lobe and yellow on the lower with a black margin . the peritoneum is silvery brown in preserved fish with widely scattered melanophores .
found from the persian gulf to japan and north australia . recorded from the helleh river in bushehr province , iran ( j . holčík , pers comm . , 1995 ) , from the bahmanshir river ( marammazi , 1995 ; eskandary
this marine species enters rivers in southern iran and presumably freshwater stocks are maintained from this marine gene pool .
the usual habitat is over sand and rock bottoms in the sea down to about 50 m , but young fish may enter estuaries and may penetrate considerable distances inland , although some fish remain at sea permanently . the frequency of penetration into iranian rivers along the persian gulf coast is not known . larger specimens are known to penetrate the shatt al arab in autumn , october to december , and this water body is an important nursery for this species , found there year round as young . adults emigrate from january to march ( al - hassan , 1990 ; hussain
. , 1987 ) . at a freshwater station on the shatt al basrah canal with salinities up to 3 . 5‰ , al - daham and yousif ( 1990 ) found this species to be the second most dominant after
, comprising 7 . 1 % by number and 10 . 9 % by weight . al - daham
. ( 1993 ) found young fish in the shatt al basrah mostly from april to october . cage - cultured fish are reared at 14 - 31°c in kuwait bay ( abou - seedo
but not other species which begin to spawn in april ( abou - seedo and dadzie , 2004 ) . savari
. ( 2011 ) showed that hormones could also be used in this regard .
a fast growing and hardy fish . life in iranian fresh waters has not been studied and information is about marine or estuarine populations .
a study of fish in the shatt al basrah canal , a man - made estuary of southern iraq , was based on mostly small and immature fish ( 49 - 181 mm standard length ) caught mostly in april - october . the length - weight relationship was w = 0 . 0511 l 2 . 893 , the dominant age group was 1 + fish , the maximum age was 3 + years , fish grew to 95 , 155 and 215 mm total length in their first three years of life , and mortality ( z ) was 2 . 23 ( al - daham et al . , 1993 ) .
in an aquaculture experiment in kuwait , fish more than doubled in weight over a 6 week period ( jafri et al . , 1981 ) . males mature at a smaller size ( 12 . 3 - 14 . 2 cm ) than females ( 24 . 3 - 26 . 2 cm ) in cage - culture in kuwait bay ( abou - seedo et al . , 2003 ) . however fish in the shatt al arab are usually less than 20 cm long and most are immature , in age groups 0 and 1 . the length - weight relationship for both sexes was w = 0 . 0916 l 2 . 6601 . the lowest condition factors were found in april and may , possibly because fish were spent after spawning or were in lower condition after the winter ( hussain et al . , 1987 ) . in kuwait , ages up to 14 years have been reported with ranges in von bertalanffy growth parameters for the years 1981 - 1985 of l ( cm ) = 38 . 3 - 52 . 29 , k = 0 . 169 - 0 . 298 , and t 0 - 0 . 213 - to - 2 . 237 . total mortality values ( z ) were 0 . 432 - 0 . 709 , this range suggesting that , even for relatively large samples ( 92 - 314 fish ) , may be too small to provide reliable estimates of z in species with a large overlap in age groups and where old fish are sampled only with difficulty . the length - weight relationship was total weight = 0 . 02874 x total length 2 . 79198 . growth and mortality estimates based on all data were l ∞ = 40 . 48 cm , k = 0 . 258 , t 0 = - 0 . 965 , t max = 14 years and z = 0 . 600 ( samuel and mathews , 1987 ) . morgan ( 1985 ) gave values of l ∞ = 43 , k = 0 . 20 and z = 0 . 97 but his study excluded fish over 30 cm and below 19 cm which accounts for the difference in mortality ; and samuel and mathews ( 1987 ) had a value about 2 . 0 for z when only fish 20 - 30 cm long were analysed .
heydarnejad ( 2009 ) gave the length - weight relationship for an iranian sample as w = 0 . 0451tl 3 . 091 .
freshwater food habits not known for iran in detail but the one specimen examined contained plant fragments and scales of a cyprinid .
in a study of the recovering hawr al hammar , diet was 60 % shrimps and 40 % insects ( hussain et al . , 2006 ) . feeds on echinoderms , worms , crustaceans , insects , bivalve molluscs and plants in the sea ( nasir , 2000 ; al - daham et al . , 1993 ) . hussain et al . ( 1987 ) found crabs and bivalves to be the most important items by percentage in the shatt al arab fish , shrimps and aquatic insects were also taken and there was significant seasonal variation , with shrimps and aquatic insects more important in december and spring . hussain et al ( 1994 ) found bivalves in 91 % of fish by number and weight in the khawr az zubayr . al - daham et al . ( 1993 ) found fish in the shatt al basrah fed on , in order of occurrence , crustaceans ( decapods , amphipods , isopods , mysids , cladocerans and cyclopoids ) , fishes ( liza spp . , barbus ( = carasobarbus ) luteus , thryssa purava , eggs and scales ) , molluscs ( corbicula , lymnaea , tryonia and sphaeriidae ) , algae ( oscillatoria , syndera , fragillaria and cladophora ) , higher plants ( vallisneria , ceratophyllum , seeds and roots ) and aquatic insects ( corixidae , hemiptera , odonata and coleoptera ) . crustaceans were most important during july and november , molluscs in may and fishes during august . hosseini ( 1998 ) examined food in coastal waters of bushehr , delvar and rostami in the northern persian gulf of iran and found 36 . 4 % to contain crabs , 34 . 0 % other fish and 13 . 4 % shrimps . snails and sea urchins were also eaten .
. ( 1993 ) have shown for fish from the shatt al arab near basrah , iraq that haematological parameters vary with reproductive phase and between sexes . cage - reared fish in kuwait bay have a prolonged spawning season from february to april . fecundity there is up to 3 , 837 , 000 eggs . spawning in the shatt al arab estuary is reported for april ( hussain and ahmed , 1995 ) and al - daham
. ( 1993 ) record a spawning season for the northwestern arabian ( = persian ) gulf as january to april with a peak in february and march . abu - hakima ( 1984a ) found the spawning period in kuwait waters to be january to march with fecundity up to 2 , 152 , 993 eggs . this species is a protandrous hermaphrodite with males dominating in smaller size groups ( 22 . 3 - 24 . 2 cm ) while females dominate in larger groups ( 24 . 3 - 26 . 2 cm ) ( abou - seedo
. , 2003 ) . samuel and mathews ( 1987 ) give a spawning date of 1 december for their kuwait sample . the gonadosomatic index was highest in february - march in hosseini ' s ( 1998 ) study in coastal waters of the northern persian gulf .
the average absolute fecundity in coastal waters near bushehr in iran was 1 , 842 , 700 , sex ratio was 1 : 1 , and the spawning peak was january - february ( hossini and savari , 2004 ) .
a good food fish of high market value seen in bazaars along the persian gulf coast and in the shatt al arab . it was selling at u . s . $ 3 . 5 - 5 . 5 per kg in kuwait about 1980 , with 213 tons landed in 1995 for a value of u . s . $ 1 , 769 , 407 ( abou - seedo
. , 2003 ) and this has been proposed for iranian waters in the persian gulf ( regunathan and kitto , 2005 ) . experimental culture has been tried at qeshm island where a million larvae were produced in march with 100 , 000 larvae 2 . 0 - 3 . 5 cm long surviving in may ( www . shilat . com , downloaded 7 june 2007 ) . it is caught by trawls , handlines , in hadra ( fixed stake nets ) and gargoor ( fish pots ) and in the sport fishery in the arabian ( = persian ) gulf ( samuel and mathews , 1987 ; carpenter
this marine species is fished commercially in the sea and populations there may be under some threat as a consequence . the status of freshwater populations is unclear as they appear quite rare and are presumably derived from marine populations at intervals .
the frequency of occurrence , detailed distribution and biology of this species in iranian fresh waters needs study .
iranian material : uncatalogued , 1 , 62 . 9 mm standard length , bushehr , about15 km above mouth in helleh river ( ca . 29
comparative material : bm ( nh ) 1974 . 2 . 22 : 1859 , 1 , 76 . 4 mm standard length , iraq , basrah ( 30º30 ' n , 47º47 ' e ) ; bm ( nh ) 1974 . 2 . 22 : 1858 , 1 , 76 . 3 mm standard length , iraq , beree ( no other locality data ) .
cichlids are found in fresh and brackish waters of central and south america , africa , madagascar , the levant , southern india , sri lanka and southern iran . there are about 221 genera and about 1606 species ( nelson , 2006 ; eschmeyer and fong , 2011 ) but only 1 is found in iran . maximum length is about 80 cm .
murray ( 2001 ) reviews the fossil record and the biogeography of the family and suggests an origin less than 65 mya in the early tertiary in contrast to other studies that give an origin over 130 million years ago . their salinity tolerance has enabled them to cross marine barriers .
mahi - e karoo , siklid irani , siklid - e hormuz , cichlid - e hormuz .
. , 2010 ) from northeast africa , on the basis of the low gill raker count , lower pharyngeal bone and teeth morphology , and morphometric characters such as a deep preorbital depth , long snout , head length and the small eye . trewavas ( 1983 ) places
trewavas , 1942 of the jordan river basin and that this requires further investigation . schwarzer
may be common responses to temperature and salinity extremes . in addition , trewavas ( 1983 ) suggests a possible relationship of
( hilgendorf , 1905 ) of the african rift valley . this species too is found in waters of high temperature and mineral content . klett and meyer ( 2002 ) group this genus with
the type locality is the
mehran river at 27°04 ' n , 54°35 ' e , hormozdgan province
( coad , 1982a ) . the holotype , 94 . 2 mm standard length , is a female with eggs in the mouth held in the canadian museum of nature , ottawa under cmnfi 1979 - 0408a ( see figure above ) . paratypes are cmnfi 1979 - 0408b , 15 , 24 . 3 - 86 . 5 mm standard length , same locality as the holotype and cmnfi 1979 - 0139 , 35 , 29 . 6 - 95 . 2 mm standard length , stream in rasul river drainage between chahar berkeh and tang - e dalan , ca . 27°25 . 5 ' n , 54°59 ' e , fars - hormozgan border . paratypes were deposited in the british museum ( natural history ) , london under bm ( nh ) 1981 . 1 . 12 : 1 - 2 ( 2 specimens ) , muséum national d ' histoire naturelle , paris under mnhn 1981 - 107 , 108 ( 2 ) , california academy of sciences , san francisco under cas 47324 ( 2 ) , the royal ontario museum , toronto under rom 36389 ( 1 ) and the university of british columbia , vancouver under bc 81 - 1 ( 1 ) .
this is the only cichlid species in iran , easily recognised by the single nostril opening on each side of the head .
this cichlid is uniquely characterised by a nearly circular dental field on the lower pharyngeal bone , the teeth there being of uniform size and not enlarged medially and by cheek , operculum , belly , isthmus and area between the pectoral and pelvic fin bases naked or poorly scaled . other significant characters are the posteriorly rounded dorsal and anal fins , short pectoral fins not reaching the vent , cycloid scales with granular posterior circuli bearing rounded or irregular protuberances , inferior apophyses for support of the swimbladder centred around the fourth vertebra ( figured in coad ( 1982a ) ) , mesethmoid not meeting the vomer , modal vertebral count 29 , median length of lower pharyngeal bone 31 . 8 - 40 . 9 % ( mean 35 % ) length of head , and pharyngeal blade / median length toothed area 0 . 6 - 1 . 0 , mean 0 . 8 .
scales are regularly arranged on the flanks except that in some large specimens the regular scale rows are interspersed with irregularly distributed smaller scales , particularly on the upper flank . scales may be absent entirely from the head , sparse above the lateral line anteriorly and on the belly posterior to the pelvic fins , absent from the dorsal and anal fin bases , absent from between the pectoral and pelvic fin bases and on the belly and isthmus anterior to the pelvic fins . however , in other specimens the head may be scaled dorsally to above the eyes , with scales variably imbricate , there may be 2 - 3 rows containing 4 - 7 minimally or non - imbricate scales on the cheek which is never completely scaled . the dorsal border of the opercle may have two large scales next to each other and a single scale may be present over the centre of the subopercular bone . scales may be present on the whole belly , isthmus and between the pectoral and pelvic fin bases , but they are minute , embedded , and non - imbricate . their extent and number varies between individuals . small to minute scales , numbering up to about 20 , are present on the caudal fin base , extending distally onto the fin membranes for more than half the fin ray length in some specimens .
flank scales below the mid - point of the spiny dorsal fin and beneath the upper lateral line are cycloid or very weakly ctenoid . the focus is central and there are 9 - 14 , mean 12 . 4 , radii on the anterior field based on 5 scales from 7 adult specimens 59 . 2 - 87 . 1 mm standard length . posterior circuli are granular so the exposed scale surface has rows of rounded or irregular protuberances .
the gut is a tightly coiled spiral with its apex ventral . gut length in 5 specimens ( 59 . 2 - 90 . 5 mm standard length ) is 6 . 8 - 8 . 3 , mean 7 . 6 , times the standard length . gill rakers are short and rounded , reaching the adjacent raker or a little further when appressed .
type ( greenwood , 1978 ) . the mesethmoid does not meet the vomer , the intervening space being cartilaginous . pores at the openings of the cephalic lateral line canals on the preorbital and preoperculum are single not multiple . the inferior apophyses for support of the anterior end of the swimbladder involve vertebrae 2 to 5 , the fourth vertebra being involved in 8 out of 10 fish examined .
teeth in the jaws are often irregularly arranged so that 4 rows are found in some places in both jaws . in some individual fish where teeth are regularly arranged there are 3 rows in the upper jaw and 4 rows in the lower jaw . number of rows decreases laterally to one at the rictus . the outer row teeth are bicuspid with the lateral cusp the smaller , while inner row teeth are tricuspid , with the central cusp the most prominent . the upper jaw has more teeth than the lower jaw .
the diploid chromosome number is 2n = 44 , comprising 25 submetacentic , 18 subtelocentric and 1 metacentric chromosomes with an arm number of 70 . the chromosome count may indicate a relationship to the levantine
scales in upper lateral line 17 ( 1 ) , 18 ( 1 ) , 19 ( 2 ) , 20 ( 8 ) , 21 ( 9 ) , 22 ( 10 ) , 23 ( 7 ) , 24 ( 4 ) , 25 ( 2 ) , 26 ( 1 ) or 29 ( 1 ) ; scales in lower lateral line 9 ( 6 ) , 10 ( 17 ) , 11 ( 14 ) or 12 ( 9 ) ; total scales in lateral series 28 ( 1 ) , 29 ( 2 ) , 30 ( 4 ) , 31 ( 9 ) , 32 ( 13 ) , 33 ( 5 ) , 34 ( 4 ) , 35 ( 4 ) , 36 ( 3 ) or 40 ( 1 ) ; scales around caudal peduncle 16 ( 15 ) , 17 ( 13 ) , 18 ( 15 ) , 19 ( 2 ) or 20 ( 1 ) ; precaudal vertebrae 14 ( 2 ) , 15 ( 53 ) or 16 ( 11 ) ; caudal vertebrae 13 ( 26 ) , 14 ( 35 ) or 15 ( 5 ) ; total vertebrae 28 ( 19 ) , 29 ( 40 ) or 30 ( 7 ) .
dorsal fin spines 14 ( 6 ) , 15 ( 46 ) or 16 ( 14 ) ; dorsal fin branched rays 9 ( 2 ) , 10 ( 36 ) or 11 ( 28 ) ; anal fin branched rays 6 ( 7 ) , 7 ( 20 ) , 8 ( 38 ) or 9 ( 1 ) ; pectoral fin branched rays 11 ( 42 ) or 12 ( 24 ) ; and total gill rakers 14 ( 6 ) , 15 ( 9 ) , 16 ( 24 ) , 17 ( 19 ) , 18 ( 6 ) or 19 ( 1 ) .
head length is greater in females while pelvic fin length is smaller in females compared to males . interorbital width is greater in males . dorsal and anal fins are larger in males when expressed in terms of longest ray length in head length ( coad , 1982a ) . colour differs as described below .
live specimens are brightly coloured in spawning condition ( based on aquarium photographs in schulz ( 2004 ) ) . the male is brick - red on the lower sides and underside of the head with black on the dorsal head surface . the underside of the head may also be black . the belly anterior to the pelvics is black . the chin is white . the sides off the head have a few , scattered white spots but the body , dorsal and caudal fins are densely covered with white spots and blotches . those on the dorsal fin are arranged in oblique rows and those on the caudal fin in bars . the anal fin has white spots also but these are not present distally . the pectoral fin has darkened rays but lacks spots . the pelvic fin has white spots proximally but less than the anal fin but is overall a dark black . other reports and photographs ( svardal ( 2006 ) and svardal and svardal ( 2006 ) ) show dominant spawning males to be black with brilliant turquoises blotches on the body but especially so on the fins . the female has an overall silvery colour with up to 9 faint to moderate flank bars . fins are yellowish . the dorsal fin has a black tilapia - mark on the posterior dorsal fin .
overall body colour outside the spawning season is a light lime green , with an iridescent tinge to the posterior edge of the operculum and on the back . the dorsal fin has light , lime - green , oblique bars , the last one or two black - edged and spot - like . the peritoneum is black .
preserved specimens have the following pigmentation . young fish have a distinct tilapia - mark , a spot on the rays of the soft dorsal fin typical of these cichlid fishes . the spot is black and is surrounded by a hyaline ring . occasionally a second spot is found posterior to the first spot . the principal spot is often retained in adult fish . young also have 7 - 11 bars along the flank which are also retained by adults but are then less distinct . in adults the dorsal fin rays and membranes are covered with melanophores interspersed with hyaline spots and irregular blotches . wavy , oblique bars are found posteriorly on the soft dorsal fin in some specimens . the caudal fin has a series of about 7 narrow bars in some male specimens while females are uniformly grey . the anal fin is narrowly barred with up to 6 vertical to oblique bars in some specimens , in others uniformly pigmented grey proximally fading to hyaline distally . pectoral and pelvic fins are not barred and are lightly pigmented , the pelvics being the darker . the head and body , including the belly , are more heavily pigmented to give an overall brown colour , lightest on the belly anterior to the pelvic fins in females . scales are not pigmented on their free margins , which are pale .
some specimens may be quite dark , particularly the back and fins and strikingly the lips .
attains 11 . 09 cm standard length or 12 . 95 cm total length ( esmaeili and ebrahimi , 2006 ) . lamboj
the cichlid is restricted to rivers draining to the straits of hormuz in southern iran ( coad , 1982a ; abdoli , 2000 ) . svardal and svardal ( 2006 ) also map this species at 27 . 770°n , 54 . 999°e , slightly to the north of samples mapped here . the distribution mapped by stiassny in keenleyside ( 1991 ) following berra ( 1981 ) is too far north . the map in berra ( 2001 ) is more accurate . abdoli ( 2000 ) records this species from the lower minab basin , lower hasan langi , middle to lower kul , gowdar and middle to lower mehran rivers .
specimens kindly sent to me by h . r . esmaeili in 1997 are from the dozdan river at 27°26 ' n , 57°10 ' e , an eastwards extension into the minab river basin . the cichlid was not collected there in the 1970s . the new record may simply be filling in a collecting gap , a natural range extension or possibly the result of an introduction .
bleher ( 2011a ) found only 2 of the 22 sites recorded by coad ( 1982 ) to still have water , although i have observed river stretches drying up and re - connecting and not always the same stretches .
trewavas ( 1983 ) suggests that the ancestor of this cichlid was distributed across the arabian peninsula in the late pliocene / early pleistocene when this area was more humid . desiccation in the pleistocene and recent periods then led to the extinction of the ancestor . a miocene - oligocene fossil
. however trewavas ( 1983 ) reports that this fossil cannot be identified as a cichlid . micklich and roscher ( 1990 ) and lippitsch and micklich ( 1998 ) also report three species of what are presumably cichlids from southwest saudi arabia in the baid formation of oligocene age at ad darb , tihamat asir . they belong to the basal grade of cichlids and to two different clades within the african assemblage . whybrow and clements ( 1999 ) record unidentified cichlidae from the early oligocene from the coastal trip of dhofar , sultanate of oman with a date of 33 mya . murray ( 2001 ) reviews these and other cichlid fossil material and the identity of omani material as cichlids appears questionable . southwest saudi arabian material is more clearly cichlid but does not point to a continuous distribution eastwards across the arabian peninsula . however , bănărescu ( 1992b ) considers that a common ancestor to
evolved in the arabian peninsula from african forebears in the miocene , the latter lineage extending its range northwards to the levant and the former eastwards to oman and southern iran , the straits of hormuz not then being in existence . murray ( 2001 ) gives an earliest date for colonisation of
ancestors to be the middle miocene when southern iran rose above sea level . she does not consider a coastwise dispersal through brackish waters of arabia to be a possible route as cichlids are not found there today but indicates a route through the tethys sea / indian ocean could be possible .
could be a relict of a once wider distribution across the tigris - euphrates basin in a northern arc rather than directly across the arabian peninsula . the absence of cichlids from southern arabia today warrant this alternative hypothesis . warm streams have probably been continually present in southern arabia and support a limited fish fauna today . there is no apparent reason why cichlids should have become extinct there . murray ( 2001 ) points out that
lives at 40 - 400 m above sea level and is limited by mountains north of the present distribution , and so it must have arrived before the mountains attained their current height , to support coad ' s hypothesis .
the headwaters of the tigris - euphrates basin are narrowly separated from the levant rift valley today and at times in the past may have had direct exchanges of faunas ( kosswig , 1965 ; 1973 ; krupp , 1987 ) . the modern absence of cichlids from the tigris - euphrates basin may be explained by low temperatures . the effects of low temperature on
, which occurs naturally in the southern levant rift valley , begin to die at 11°c and cease all motion at temperatures below 10°c ( chervinski and lahav , 1976 ) . most of syria , northern iraq and the northern arabian peninsula have temperatures below 10°c in winter ( beaumont
is found mainly in saline streams . this hypothesis can only be confirmed by fossil discoveries .
the streams in which this species lives are subject to desiccation with continuous flow breaking up into isolated pools . the survival of cichlid populations in these pools varies between years and some pools may be fishless in one year and populated in another .
the area around the straits of hormuz is rich in salt domes and consequently most surface streams are saline , up to 80 ms . cichlids are found in these streams but also in the sar khun oasis which is fresh with a conductivity of 1 . 6 ms . apparently they can be transported at 10 ms as this is less stressful . stream waters are cloudy to clear and colourless . water temperatures in winter ( november to march ) range from 15 to 33°c and would be considerably higher in summer when air temperatures reach 45°c with no riparian shade and low water levels . lamboj
. ( 2006 ) and svardal ( 2006 ) give water temperatures of 33 - 40°c and conductivity of 45 - 75 ms .
streams are 1 to 50 m wide and consist of alternating riffles and pools with occasional backwaters . the bottom is pebbles , sand or mud . aquatic vegetation is restricted to encrusting algae .
unknown . esmaeili and ebrahimi ( 2006 ) give a significant length - weight relationship based on 379 fish measuring 2 . 74 - 11 . 09 cm standard length . the
- value > 3 indicating a fish that becomes more rotund as length increases ) .
gut contents of 5 specimens ( 41 . 2 - 90 . 5 mm standard length ) included only algae and diatoms suggesting food is scraped from rocks and from bottom deposits . this is consistent with an elongate gut and black peritoneum . aquarium specimens eat algal tabs but also appreciate insects and fish remains .
this species is a mouth brooder . a breeding female and a male were caught in a backwater on march 18 of the mehran river ( the type series ) . this backwater was 1 - 5 m wide , maximum depth was 40 cm over a mud bottom , the water was cloudy and highly saline ( 40ms ) and temperature ranged from 26°c at the mouth of the backwater to 33°c at its head . eggs in fish taken in november and january are small so the breeding season is deduced to be around march . five eggs ranged in length from 3 . 2 to 3 . 8 mm , mean 3 . 6 mm and in width from 2 . 4 to 2 . 7 , mean 2 . 5 mm . total number of eggs from 2 females , 59 . 0 - 59 . 2 mm standard length was 36 and 38 respectively . eggs are yellow - orange in preserved fish .
a female 116 . 9 mm standard length from the mehran river had 153 larvae in her mouth , ranging in length from 9 . 6 to 10 . 9 mm ( h . r . esmaeili , pers . comm . , 6 october 2005 ; esmaeili
. ( 2009 ) found a sex ratio biased towards males in may and june , presumably because males were defending nests and easily caught , or possibly differential survival of the sexes . they suggest that the breeding season begins in march and lasts until the end of june with a peak in may . eggs attained 3 . 76 mm and fecundity reached 151 eggs with a relative fecundity of 5 . 4 eggs per gram body weight . esmaeili et al . ( 2010 ) detail gonad morphology and histology and confirmed peak spawning in may .
schulz ( 2004 ) observed fish in the field and found each male occupying a territory defending a nest about 1 m from each neighbouring nest . the nests were made on light grey , fine sand and consisted of a pit approximately 15 cm in diameter . the pit was black because of anoxic conditions below the sand surface . the actual nest was about the same as the body length of the fish ( 8 - 10 cm ) and lay at the centre of the pit . the pit was surrounded by a rim about 1 . 5 cm high with an internally indented margin . simpler pits are built where building materials are unavailable . females were present in schools in deeper water in the river centre . individual females swam purposefully to the nest defended by the male . the male directed the female to the nest centre with folded up fins while the female spread her fins and showed radiating colour changes . spawning occurred immediately and neighbouring males intervened continuously at a speed that did not allow full analysis of the movements . a defending male would chase away an intruding male allowing another male into the unprotected nest to mate with the female . a clutch of eggs was always inseminated by a whole group of males .
piscivorous birds have been observed along the streams where the cichlid is found . ansary
saadati ( 1977 ) suggests that this salt - tolerant species could be a valuable resource if introduced into the saline and fishless waters of internal basins . however this is not advisable since the native fauna , evolved in a fishless environment , could be devastated before it has even been documented . esmaeili
. ( 2009 ) note that it is eaten by local people when available in large numbers in spring . it is now an aquarium fish in germany ( schulz , 2002 ; 2004a ; 2004b ; oliver lucanus , pers . comm . , 23 january 2004 ; lamboj
. , 2006 ; svardal , 2006 ; svardal and svardal , 2006 ) and juveniles sell for about $ 80 each urltoken 21 march 2010 ) . articles in aquarium magazines give photographs in spawning condition , including mouth - brooding , and details for their maintenance , including water with a conductivity of 50 - 70ms / cm nacl or sea salt mixture , tank water changed once a week , vegetarian food tabs ( containing the blue - green alga
) , and a temperature of 20 - 35°c , optimally 27°c . it has been noted that males , in continually defending a nest and courting ,
wear out
earlier than females ( thomas schulz ,
may well be on its way to extinction - if it is not gone already
. bailey ( 2006 ) apparently repeats this . however its habitat is mostly saline streams which cannot readily be used for agriculture or industry . the surrounding area is not industrialised , nor likely to be , and was never a war zone so pollution is not a problem for this species .
flash floods are probably a significant problem as water drains rapidly off vegetation barren land . the scouring action may well displace or strand cichlids . mouth brooding offers protection against floods and against associated fishes .
svardal ( 2006 ) and svardal and svardal ( 2006 ) give details of capture , transport and aquarium care of this species .
rabbaniha ( 1993a , 1993b , 1994 ) gives farsi accounts of this species and cichlids in general . the account is based principally on coad ( 1982a ) .
type material : see above , cmnfi 1979 - 0408a , cmnfi 1979 - 0408b , cmnfi 1979 - 0139 , bm ( nh ) 1981 . 1 . 12 : 1 - 2 , mnhn 1981 - 107 , 108 , cas 47324 , rom 36389 and bc 81 - 1 .
introduced to the tigris river basin in iraq but did not apparently survive winterkill ( herzog , 1969 ) . mutlak and al - faisal ( 2009 ) , however , record
) from basrah in southern iraq and this species could easily become established in iran . no iranian record confirmed as yet . red tilapias (
sp . ) have been studied in aquaponic systems in iran so there is a potential for an exotic release ( rafiee and saad , 2005 ) . fingerlings from indonesia have been reared using saline waters at bafgh , yazd province in 3 ton fibreglass tanks . larvae were successfully grown to 2 . 0 kg at 28±1ºc (
introduced to the tigris river basin in iraq but did not apparently survive ( job , 1967 ) . redbelly tilapias are established in the syrian euphrates ( r . beck , pers . comm . , 2000 ) and a recent report by beshar abd al - hussain al - saadi (
. , 10 october 2006 ) of a cichlid at al musayyib on the euphrates river in iraq may well be this species . mutlak and al - faisal ( 2009 ) , record this species from basrah in southern iraq and these could spread to iranian waters . no iranian record as yet . the farsi name is تيلاپيا ( = tilapia ) .
the gobies are a world - wide family found mostly in warmer marine waters although some species enter fresh water and others live there permanently ( see also marine list in checklists in the introduction ) . the number of species is high and this may be the most speciose fish family in the world with about 248 genera and about 1630 species , perhaps more ( eschmeyer and fong , 2011 ) . a diversity of gobies occurs in the caspian sea basin . not all caspian gobies have valid iranian records but most will probably be found there . several gobies penetrate southern waters of iran from the persian gulf and sea of oman and are described here . others will probably be discovered when more detailed surveys are made .
gobies are easily distinguished by their pelvic fins being united as an adhesive or sucking disk or cup . body form and coloration are diverse . the pattern of head canals , canal pores and neuromasts is distinctive and used in identifying and relating species ( except in
( pinchuk , 1991 ) ) . however the neuromasts may be sunken in narrow furrows or pits and completely covered by epithelium so they do not preserve well and this can lead to confusion in identifications ( zambriborshch , 1968 ) . there is usually a short spiny dorsal fin ( 2 - 8 flexible spines ) separated from , but close to , a soft dorsal fin . the soft dorsal fin and anal fin are longer than the caudal peduncle . scales may be cycloid , ctenoid or rarely absent . no obvious lateral line . there are 5 branchiostegal rays . gill membranes are connected to the isthmus and gill openings are moderate to wide , or very restricted in the mudskippers . the head is usually blunt and the mouth is usually large . teeth are usually small and conical in one to several rows in both jaws . miller in miller ( 2003 ) gives a suite of osteological characters defining the family .
most gobies are quite small ( 5 - 10 cm ) and they are often very abundant . maximum size is about 50 cm . some of the world ' s smallest vertebrates are gobies from the indian ocean , mature at 8 mm . others , however , are large and form part of fisheries in both the caspian sea and the indian ocean . they are not significant food fishes in iran . gobies tend to rest on the bottom and move in sudden , characteristic dashes . the male goby guards a nest . food is crustaceans , worms , molluscs and small fishes . many gobies are important in the aquarium trade since they are beautifully coloured , small and tough .
they are known generally as gav mahi ( = cow fish ) or sag mahi ( = dog fish ) or contain the word gel ( = mud ) in iran . a general review in farsi of the caspian gobies is given by aslaanparviz ( 1991 ) .
the males of some caspian species become black during the spawning season , their fins elongate , head shape alters and some even become naked . loss of tubercles in adult male gobies of the genus
makes it possible to identify only juveniles and females . the males build nests and guard the eggs . life span of certain caspian species is said to be as short as one year , e . g . some species of
, as much as 10 - 15 % of total biomass in some areas ( mamedov , 2006 ) .
the black and caspian sea basins contain an endemic sarmatian fauna of gobies . there are two main clades , the gobiine - benthophilines ( or transverse gobiids ) and the pomatoschistines ( or sand gobies ) , that have probably been distinct for at least 40 million years . miller ( 2001 ) and miller in miller ( 2003 ) reviews the evolutionary history of these two clades and their anatomical differences based on head papillae and osteology . the transverse gobiids include
. the sarmatian fauna was separated from the atlantic - mediterranean fauna with the isolation of the paratethys during the late miocene messinian salinity crisis as the mediterranean dried . partial flooding of the mediterranean from the paratethys in the early pliocene allowed sarmatian gobies to spread westwards . within the ponto - caspian basin , evolution of species flocks was favoured by basin sub - divisions and rejoinings . the benthophilines may be a monophyletic group from these events .
ahnelt and duchkowitsch ( 2004 ) give information on the neogobiine stock . about 12 - 13 million years ago in the middle miocene , the ponto - caspian endemic and ancestral neogobiine stock may have differentiated from an atlantic - mediterranean gobiine stock . at this time the paratethys was a sea with reduced salinity and a high level of endemism . the
stock that invaded the mediterranean basin after that sea was restored about 5 million years ago in the late miocene .
ranges from 4 . 29 to 6 . 25 mya and the paper gives divergence times for major lineages in relation to geological events in the ponto - caspian . these events include connections with , and isolation from , the world ocean and salinity changes in a range of 1 - 30 p . p . t . over the last 5 million years . most genera diversified about 5 mya when the black and caspian seas separated .
the principal recent works on the systematics of caspian gobies are by v . i . pinchuk , d . b . ragimov , ye . d . vasil ' yeva , h . ahnelt and p . j . miller . earlier works are by b . s . iljin ( also spelled il ' in or ilyin ) . later molecular studies are cited above .
other gobies in iran are the familiar tropical mudskippers which can move quickly over land , using the muscular - based paired fins to row across mud , and some can even clasp and climb mangroves . they can live out of water because the gill openings are small to prevent desiccation of the gills , oxygen can be taken into the chamber and absorbed through the gills and chamber wall , and they can also absorb oxygen through their skin . they often rest with the tail immersed in water for this purpose or roll around in shallow water to moisten themselves . they may live entirely in water , or will come onto land even when there is enough oxygen in the water . their eyes are high on the head , protruding and able to revolve independently , and have a movable lower lid . the eyes are retracted periodically into small cups below the head to moisten them . such eyes are very effective as a means to watch for potential enemies on land but their vision under water is blurred . mudskippers have elaborate reproductive behaviour which involves tail standing , flip - flops , and fin displays . they are very territorial and defend their territory against other mudskippers and crabs . they can deliver a skin - breaking bite to humans even though they are only about 15 cm long !
this genus comprises only a single species and so its characters are those of the species . the snout is very distinctive and details of neuromasts are not given here as they are not needed in identification , although of importance in relating the genus . the genus is closely related to the tadpole goby clade comprising
and details are give in miller in miller ( 2004 ) . this author also gives an alternative terminology for the arrangement of neuromasts than that of ahnelt
eichwald , 1831 by berg ( 1927 ) but later iljin ( 1930 ) erected a new genus because of its unusual and distinctive morphology . the type locality is the caspian sea at 37°58 ' n , 52°22 ' e at a depth of 294 m ( but see below ) .
. ( 2000 ) although berg ( 1927 ) mentions 15 fish in his description . ragimov ( 1985 ) states that berg described this species from a single young specimen and also visually observed 15 others for a total of 16 in the type series .
the duckbill tadpole goby is characterised by the elongate and flattened head which is similar to a duck ' s bill . unlike gobies of the genus
first dorsal fin with 3 - 4 spines , usually 4 , second dorsal fin with 1 spine followed by 8 - 11 , usually 10 , soft rays . anal fin with 1 spine followed by 8 - 11 soft rays . pectoral fin rays 14 - 16 . gill rakers on the posterior part of the arch are very short and anteriorly are minute . pit organs on the side of the head are papilliform and clearly visible with the naked eye . further details of anatomy are given by ahnelt
iranian specimens had the following meristics : - first dorsal fin with 4 ( 4 ) spines ; second dorsal fin with 1 ( 4 ) spine followed by 10 ( 4 ) soft rays ; pectoral fin rays 14 ( 1 ) , 15 ( 2 ) or 16 ( 1 ) ; anal fin with 1 ( 4 ) spine followed by 11 ( 4 ) soft rays ; and total vertebrae 29 ( 4 ) .
overall , colour is a light grey or pale fawn fading to a whitish grey on the belly . various speckles and melanophores are found on the back and upper flank . the dorsal , caudal and pectoral fins have dark grey speckles . the head sides from the snout to the cheek are dark with transversal suborbital papillae series whitish giving the impression of narrow light stripes below the eye and on the cheek . the peritoneum is black or densely covered in fine speckles .
reaches 11 . 2 cm , or 13 cm total length ( jolodar and abdoli , 2004 ) . females may be larger than males ( mean total length 84 mm versus 77 mm ) .
known only from the caspian sea and one of the endemic sarmatian fauna ( see family account ) .
found to a depth of 294 m on white silt bottoms according to berg ( 1927 ) but the data in zisp states 244 sazhems ( = 446 . 5 m ) . recent iranian material is from 45 - 80 m , at 9 . 7 - 16 . 4°c at 50 m ( ahnelt
. , 2000 ) and jolodar and abdoli ( 2004 ) state it lives mainly at 50 - 100 m depths in the south caspian sea .


hampala dispar is a southeast asian species of cyprinid , endemic to the basin of the mekong .

it is found in thailand , laos and cambodia .

individuals may reach a length of 35 cm .

hampala dispar

y . taki and a . kawamoto , 1977 - japanese journal of icthyology 24 ( 1 ) : 61 - 65 differentiation of the cyprinids , hampala macrolepidota and h . dispar .
the mun river at ubon ratchathani , eastern thailand , type locality of h . dispar .
dispar : from the latin dispar , meaning ‘unlike , dissimilar’ , in reference to the differences in colour pattern and morphology which separate it from h . macrolepidota , the type species of this genus .
although it needs plenty of space h . dispar makes a more suitable aquarium resident than the more commonly - traded congener h . macrolepidota due to its significantly smaller adult size .
doi , a . and y . taki , 1994 - japanese journal of ichthyology 40 ( 4 ) : 405 - 412 a new cyprinid fish , hampala salweenensis , from the mae pai river system , salween basin , thailand .
j . r . ryan and y . b . esa , 2006 - zoological science 23 ( 10 ) : 893 - 901 phylogenetic analysis of hampala fishes ( subfamily cyprininae ) in malaysia inferred from partial mitochondrial cytochrome b dna sequences .
juveniles of the two species can appear very similar as the body blotch is extended vertically in young h . dispar , plus both display a broadish dark band across the caudal peduncle , a second , thinner band across the base of the caudal - fin , and a small blotch above the anal - fin . all of these markings are less intense in h . dispar while in h . macrolepidota there is additional dark patterning above and below the eye and running downwards from the nape to the pelvic fins .
it is worth noting that the body markings tend to fade in very large specimens of all hampala spp . , and it’s possible that additional species will be described in the future as a phylogenetic study published in 2006 concluded that the form of h . bimaculata from central and southern parts of the malaysian state of sarawak , borneo ought to be considered distinct , for example .
hampala spp . are voracious feeders especially when maintained in numbers . some aquarists have observed that the ‘alpha’ individual in a group will lead the others in a pack - style behaviour , and anglers’ reports state that the water surface will literally boil when a shoal is feeding . so enthusiastically does it attack food that it’s sometimes recommended as a useful tankmate for fastidious or newly - introduced fishes that are refusing to eat .
h . macrolepidota is easy to identify by colour pattern , which comprises a dark vertical band originating anterior to the dorsal - fin and extending below the lateral line , plus the presence of black marginal stripes in both lobes of the caudal - fin . h . dispar possesses only a single dark blotch - like marking on the body and has less well - defined marginal stripes on the caudal lobes .
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justification : the species is endemic to the mekong basin in thailand , lao pdr , and cambodia . it is adaptable to a range of habitats and is considered least concern at present .
described from the mun river at udon , thailand . endemic to the mekong basin in thailand , lao pdr , and cambodia ( mekong , tributaries and the tonle sap lake ) .
predominantly a riverine fish , preferring clear , well - oxygenated , running water with substrates of sand , gravel , rock or mud . an adaptable species , it can also be found in both upland and lowland waters . during the rainy season it migrates into areas of inundated forest to feed and spawn .
rainboth 1996 ) , and in swamps , marshes and slow - flowing waters ( m . kottelat pers . comm . 2011 ) it is now also found inhabiting many stiller and / or permanent bodies of water as a result of human activity including agriculture and damming of river channels . anecdotal accounts from aquarists suggest that it feed chiefly on crabs , shrimp and insects but also smaller fishes .
likely to be impacted in parts of its range by overfishing and perhaps habitat degradation .
research is required on the species distribution , population trends , threats , and habitat and ecology .
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maturity : l m ? range ? - ? cm max length : 35 . 0 cm sl male / unsexed ; ( ref . 30857 )
has a round midlateral blotch under the dorsal - fin origin in adults and a plain grey caudal fin ( ref . 27732 ) ; juveniles lack black teardrop - shaped marking on cheek ; barbel always shorter than eye width ( ref . 12693 ) .
occurs in slowly moving or standing water habitats ( ref . 12693 ) . encountered also in rapid - running mountain streams of the middle mekong ( ref . 12975 ) . common in impoundments , with small individuals frequenting areas of dense vegetation . feeds mainly on prawns , crabs , and shrimps , along with some insect larvae and some fish as well . breeds at the start of the rainy season and the young are found in seasonally flooded habitats in june . marketed fresh ( ref . 12693 ) .
rainboth , w . j . , 1996 . fishes of the cambodian mekong . fao species identification field guide for fishery purposes . fao , rome , 265 p . ( ref . 12693 )
phylogenetic diversity index ( ref . 82805 ) : pd 50 = 0 . 5078 [ uniqueness , from 0 . 5 = low to 2 . 0 = high ] .
bayesian length - weight : a = 0 . 00955 ( 0 . 00519 - 0 . 01756 ) , b = 3 . 06 ( 2 . 90 - 3 . 22 ) , in cm total length , based on lwr estimates for this species & ( sub ) family - body ( ref . 93245 ) .
trophic level ( ref . 69278 ) : 3 . 7 ±0 . 61 se ; based on food items .
resilience ( ref . 69278 ) : medium , minimum population doubling time 1 . 4 - 4 . 4 years ( preliminary k or fecundity . ) .
vulnerability ( ref . 59153 ) : moderate to high vulnerability ( 49 of 100 ) .
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considered endemic to the section of the mekong river basin which flows through northern laos before forming the border with thailand and eventually entering cambodia just below the khone pha pheng falls . it’s distribution thus overlaps that of its widespread congener h . macrolepidota .
type locality is ‘monam mun at udon , thailand’ , which appears to correspond to the lower section of the mun river , a tributary which joins the mekong in ubon ratchathani province , eastern thailand .
predominantly a riverine fish preferring clear , well - oxygenated , running water with substrates of sand , gravel , rock or mud although it is adaptable and can be found in both upland and lowland , standing or flowing waters .
during the rainy season it is known to migrate into areas of inundated forest to feed and spawn , and can now be found in many impounded water bodies as a result of human activity such as agriculture and damming of river channels .
choice of décor is not as critical as water quality and the amount of open swimming - space provided . however should you possess the means to both provide and decorate a sufficiently - sized aquarium this species a set - up designed to resemble a flowing river with a substrate of variably - sized rocks and gravel , some large water - worn boulders and perhaps a couple of driftwood branches is recommended .
like many fishes that naturally inhabit running waters it’s intolerant to the accumulation of organic wastes and requires spotless water at all times in order to thrive . it also does best if there is a high level of dissolved oxygen and a decent level of water movement in the tank so external filters , powerheads , etc . , should be employed in order to obtain the desired effect .
be sure to fit the aquarium with a heavy , tightly - fitting cover as larger cyprinids can be quite skittish at times and usually possess a powerful leap .
predatory with a capacious mouth . stomach analyses of wild specimens from cambodia have shown it to feed chiefly on crabs , shrimp and insects with some smaller fish also taken . in the aquarium it will accept dried foods but should not be fed these exclusively with daily meals of live and frozen foods key to keeping it in the best of health .
smaller specimens can be offered bloodworm , small earthworms , chopped prawn and suchlike while adults will take whole prawns , larger earthworms , mussels , whitebait , etc . take care not to overfeed as it will gorge itself given the opportunity .
it should not be fed large amounts of mammalian / avian meat such as beef heart or chicken . some of the lipids contained in these meats cannot be properly metabolised by the fish and can cause excess deposits of fat and even organ degeneration . similarly there is no benefit in the use of ‘feeder’ fish such as livebearers or small goldfish which carry with them associated risks such as the introduction of parasites or disease .
captures its prey using suction rather than aggressively biting and otherwise peaceful with anything it can’t swallow , although its speed of movement and feeding habits suggest that slow - moving or timid tankmates would probably be out competed . smaller specimens are easy to maintain alongside other species but as they grow become increasingly powerful and domineering when food is available meaning companions must be chosen with care .
similarly - sized cyprinids , characids , catfishes and larger botiid loaches perhaps constitute the best choices . a large mekong - themed community could be an interesting project with options including barbonymus , cyclocheilichthys , osteochilus , and hypsibarbus wetmorei species among many others .
though gregarious by nature it is a shoaling rather than schooling species which develops a distinct pecking order and therefore should always be maintained in a group of five or more . if only two or three are present the subdominant fish may be subjected to excessive antagonism whereas solitary specimens tend to act rather nervously .
h . sabana also has a single body marking but a higher count of circumpeduncular scales ( 30 - 32 ) and relatively few lateral line scales ( 12 - 15 ) compared to its congeners . h . ampalong , h . bimaculata and h . salweenensis can be trickier to separate since they all have two body blotches . h . ampalong possesses more lateral line scales than h . salweenensis ( 28 - 31 vs . 26 - 27 ) whereas in h . bimaculata the body markings are saddle - shaped and the anterior blotch is positioned underneath the posterior half of the dorsal - fin ( below the dorsal - fin origin in the other two ) .
smith , h . m . , 1934 - journal of the siam society , natural history supplement 9 ( 3 ) : 287 - 325 contributions to the ichthyology of siam . ix - xix .
kottelat , m . , 2013 - raffles bulletin of zoology supplement 27 : 1 - 663 the fishes of the inland waters of southeast asia : a catalogue and core bibiography of the fishes known to occur in freshwaters , mangroves and estuaries .
smith , h . m . , 1934 - journal of the siam society , natural history supplement v . 9 ( no . 3 ) : 287 - 325 contributions to the ichthyology of siam . ix - xix .
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special publication of the center for biodiversity research and information , no . 1 , vol 1 - 3
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 .
occurs in slowly moving or standing water habitats ( ref . 12693 ) . encountered also in rapid - running mountain streams of the middle mekong ( ref . 12975 ) . common in impoundments , with small individuals frequenting areas of dense vegetation . feeds mainly on prawns , crabs , and shrimps , along with some insect larvae and some fish as well . breeds at the start of the rainy season and the young are found in seasonally flooded habitats in june . marketed fresh ( ref . 12693 ) .
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freshwater ; benthopelagic ; potamodromous ( ref . 51243 ) . tropical , preferred ?