the white sucker ( catostomus commersonii ) is a freshwater cypriniform fish inhabiting the upper midwest and northeast in north america , but is also found as far south as georgia and new mexico in the south and west .

the fish is commonly known as a " sucker " due to its fleshy papillose lips that suck up organic matter and aufwuchs from the bottom of rivers and streams .

other common names for the white sucker include bay fish , brook sucker , common sucker , and mullet .

the white sucker is often confused with the longnose sucker ( catostomus catostomus ) , because they look very similar .

white sucker

other names : sucker , common sucker , eastern sucker , mullet , brook sucker , gray sucker , mud sucker , slender sucker , mullet , whitehorse . the ojibwe name is namebin . the phrase
namebinikaa
means
there are many white suckers
in ojibwe . that ' s a phrase that good roughfishers should keep handy !
in colorado , the white sucker is replacing native suckers in the rio grande and colorado river drainages ( walker 1993 ) . hybridization between native flannelmouth and bluehead sucker , and non - native white sucker
young provide considerable forage for game species . white sucker x longnose sucker hybrids have been found in several places in montana .
the white sucker is best described as having a
torpedo shaped
body .
distribution of the white sucker in north america ( after scott & crossman 1973 ) .
endocrine changes during natural spawning in the white sucker , catostomus commersoni . ii . steroid hormones .
map of white sucker distribution across the united states . ( credit : u . s . geological survey )
in manitoba , there are 7 species of suckers , but the white sucker is by far the most common .
endocrine changes during natural spawning in the white sucker , catostomus commersoni . ii . steroid hormones . - pubmed - ncbi
health of white sucker within the st . louis river area of concern associated with habitat usage as assessed using stable isotopes
yellow perch , rock bass , blue gill / pumpkinseed , white perch , white bass , & crappie .
white suckers average about a pound but fish of up to 7 pounds have been caught . extremely large white suckers can be confused with common carp - but the white sucker has smaller scales , no barbels , and a slimmer profile .
saint - jacques , n . , h . harvey , d . jackson . 2000 . selective foraging in the white sucker (
mostly eat their eggs or small white suckers up to about 203 mm long . small white suckers are also eaten by
state of michigan . 2013 .
white sucker , catostomus commersonii ( pictured ) longnose sucker , catostomus catostomus
( on - line ) . www . michigan . gov . accessed october 21 , 2013 at urltoken .
a doppelganger for the longnose sucker , the white sucker also mimics the longnose sucker ' s actions and habits to a tee . with a toothless smile perfect for its bottom - feeding diet , the white sucker spends most of its time in warm , shallow waters . you will find these fish near obstructions and windfalls that create divets in great lakes bays , estuaries , and tributaries , but a search in deeper lake superior waters will garner a white sucker spotting , too . as an adult predator when lake trout are scarce , sea lampreys prove a challenge to this fish ' s existence , as it has for the longnose sucker . the white sucker is no wannabe of its longnose relative , though ; it ' s its own fish , and it ' s quite happy to have it that way .
minnesota department of natural resources . 2013 .
white sucker catostomus commersonii
( on - line ) . accessed october 20 , 2013 at urltoken .
. the latter two primarily feed on eggs and small white suckers up to about 203 mm long . small white suckers are also eaten by
the white sucker is distributed throughout much of north america . it occurs almost everywhere in manitoba , except in a small region of the extreme north of the province .
white suckers that are less than a year old form schools of several hundred fish . adult and juvenile white suckers feed day and night but are more active at night when they move into shallower water . white suckers coordinate their movement so they are inshore during the evening and offshore by morning . in stream habitats , large white suckers can be found in deep pools . white suckers can be very good at moving long distances , in one such case , an individual white sucker ended up 56 km away from the area it was tagged 5 years before .
young white suckers less than a year old form schools of several hundred fish . adult and juvenile white suckers feed day and night but are more active at night when they move into shallower water . white suckers tend to coordinate their movement so they are inshore during the evening and offshore by morning . in stream habitats , large white suckers can be found in deep pools . white suckers are also excellent dispersers , particularly after spawning . in one such case , an individual white sucker ended up 56 km away from the area it was tagged 5 years previously .
white suckers are an important food source for several fish and land animal species .
sutton , m . 2009 . blue sucker stock characteristics in the wabash river indiana - illinois , usa .
assembly of ribosome - depleted rna isolated from white sucker included a linear contig of 3 , 519 bp with blastx similarity to hepadnaviruses . our finished genome , 2014 wshbv rr173 ( genbank accession number
and white suckers grow most efficiently in conditions that are 19 to 26 degrees celsius .
breeding season white suckers breed in the spring , usually from april to early may .
white suckers are an important food source for several species of fish and land animals .
commonly feed on white suckers during foraging . they are also fed on by bass ,
white suckers are tremendous fighters . the average sucker weighs several pounds , so be ready for battle if you tangle with one on a stream ! the fight of a sucker is usually a series of strong , determined runs , but occasionally they will surprise you by jumping and even tailwalking when hooked . the rubbery lips of the sucker hold hooks well , so be sure to bring a forceps along to disgorge hooks . and congrats , catching white suckers on flies is a challenge that few anglers pursue .
yeager , b . , k . semmens . 1987 . early development of the blue sucker , cycleptus elongatus .
map of white sucker sample locations . these include the st . louis river , green bay and lower fox river , milwaukee estuary , detroit river and maumee river areas of concern , and the root river .
mestl , g . 2009 . seasonal use distributions and migrations of blue sucker in the middle missouri river , usa .
where do they live ? the white sucker is one of minnesota ' s most common fish , and it is the most widely spread distributed sucker in minnesota . it is most common in the eastern and northern portions of the state . white suckers are benthic ( bottom dwellers ) and live in all kinds of lakes and streams from clean , stream - fed brooks to slow - moving , turbid ( cloudy ) rivers .
conservation and management the white sucker is the most common sucker in minnesota and one of the most abundant of all species . it had no special conservation status , but is considered an important forage species for many sport fish . it is also a very important bait species and is reared for that purpose , as well as commercially collected
researchers puzzle over precisely how teleost fishes , such as this spotted sailfin sucker catfish , evolved a dazzling array of forms .
opisthomyzon , a 30 - million - year - old remora . white box shows suction disk .
prevalence of core protein rna transcription in liver tissue of white sucker collected in the great lakes ( united states ) region . ( a ) absolute number of fish with detectable transcripts . ( b ) normalized copy number of transcripts .
white suckers feed at night . adult diet consists of insect larvae , mollusks , and other invertebrates .
the white sucker is the most common species of sucker in north america . although scorned by many anglers , it is not only a fun and spunky game fish , but an ecologically important species as well . in recent years , more and more open - minded anglers have been giving this common , hard - fighting , and delicious species the recognition it deserves .
white suckers could be a valuable sport fish , although they are not caught as often as some other species . these fish are caught by commercial fisheries as food for both humans and animals , including pets . white suckers are also farmed in ponds . the most important economic value of white suckers is in their use as food or bait . the bait industry for white suckers was valued at $ 300 , 000 in wisconsin in 1968 . white suckers have sweet , white flesh , although it is not as firm as some other sport fish . likewise , white suckers contain large bones between their muscle segments that can make them difficult to prepare , but they can be smoked , filleted , or ground into patties .
burr , b . , j . garvey . 2006 . ecology of larval blue sucker ( cycleptus elongatus ) in the mississippi river .
the longnose or northern sucker ( catostomus catostomus ) is also widely distributed in northern north america , and it also occurs in eastern siberia . the long - nose sucker generally inhabits cooler waters and occurs in deeper lakes and larger rivers and streams than the common sucker . this species is exploited commercially on the great lakes and elsewhere , although it is not considered to be a high - value species of fish . other species of suckers are more local in distribution , for example , the sacramento sucker ( c . occidentalis ) of northern california .
; see also table s1 in the supplemental material ) . these samples were preserved in rnalater ( life technologies , grand island , ny ) for a transcriptome assembly project ( prjna282680 ) and quantitative gene expression analyses . a liver sample from a white sucker collected from michael brook near carmel , ny , was included for this purpose as well . tissue was not collected for dna applications from these fish . in an attempt to collect samples suitable for dna analysis , we collected white sucker (
daugherty , d . , t . bacula , m . sutton . 2008 . reproductive biology of blue sucker in a large midwestern river .
although white suckers feed on fish eggs , this does not seen to adversely affect the populations of other fish .
there are over one hundred species of suckers . the common or white sucker ( catostomus commersoni ) is a widespread species throughout much of northern and central north america . this species has a round mouth , useful for feeding on its usual prey of bottom - dwelling insects , crustaceans , molluscs , and other invertebrates . the common sucker is a relatively large species , attaining a length of up to 1…
the white sucker catostomus commersonii is a freshwater teleost that is endemic to river systems in the midwestern and northeastern united states . the widespread distribution and life history of white suckers has made them a target species in numerous contaminant - monitoring and effects studies ( 1 , – 3 ) . the prevalence of tumors in white sucker is currently used as an indicator of exposure to environmental contaminants and is also a criterion used in the assessment and listing or delisting of areas of concern ( aocs ) throughout the great lakes region . fish tumors or other deformities , specifically in white sucker or brown bullhead , are listed as one of the “beneficial use” impairments at great lakes aocs ( 4 ) . in 2010 , the great lakes restoration initiative specifically targeted certain priorities , one of which was the evaluation and monitoring of progress in aocs ( 5 ) . one component of this program was the assessment of wild populations present at potentially impacted sites . a suite of biomarkers ranging from the molecular to the organismal level was developed for multiple fish species ( 6 ) . during the development of a hepatic transcriptome for white sucker , we identified the presence of a novel hepatitis b - like virus .
these fish can be found in most every stream flowing into either lake erie or lake ontario come spring and early summer . spearing was once a legal method for taking these fish in the tributaries , but that option is no longer available to anglers . instead , try fishing with dew worms at night . a state record sucker was caught in the niagara river several years ago but it failed to make the books because of a low level of awareness . the top white sucker is five pounds , three ounces ; the record redhorse sucker is 11 pounds , 11 ounces .
eitzmann , j . , a . makinster , c . paukert . 2007 . distribution and growth of blue sucker in a great plains river , usa .
for invertebrate prey . removing white suckers from areas with both species causes more invertebrates and fewer zooplankton to be eat by yellow perch , which increases their growth rates . however , removing white suckers does not significantly increase the population of yellow perch .
snyder , d . e . , and r . t . muth . 1990 . description and identification of razorback , flannelmouth , white , utah , bluehead , and mountain sucker larvae and early juveniles . colorado division of wildlife tech . publ . no . 38 . 152 pp .
the recently redescribed summer sucker ( catostomus utawana ) of the adirondack region of new york formerly was included in this species ( see morse and daniels 2009 ) .
(
status report on blue sucker ( cycleptus elongatus ) , a candidate endangered or threatened species
, 1993 ; eitzmann , et al . , 2007 )
a large group of fish , numerous species of suckers inhabit new york state ' s waters . some , such as the redhorse , are only found in a few waters in the state , while others , such as the white sucker , can be found all over new york state .
white suckers are a very common and wide - ranging species with large population sizes and are considered a species of least concern .
when they are younger and smaller , white suckers are preyed on by northern pike , muskellunge , bass , walleyes and atlantic salmon .
juvenile white suckers show a more mottled coloration . they are often sold in bait shops as bait for northern pike and flathead catfish .
, and algae . adult white suckers mostly feed on zooplankton and invertebrates , but they may also specialize in one or the other .
white suckers feed on fish eggs ; however , it does not seem to have a negative impact on the populations of other fish .
white suckers are an under - utilized , yet potentially valuable sport fish . they are caught using worms , spears , dip nets , wet flies , and spinning lures . commercial fisheries catch them using seines , fyke , pound nets , gill nets , and trawls . their catch is then used as food for both humans and animals , including pets . white suckers are also farmed in ponds and pursued by anglers using spears , hooks , and fishing line . the most important economic value of white suckers lies in their use as food or bait . the bait industry for white suckers was valued at $ 300 , 000 in wisconsin in 1968 . white suckers have sweet , white flesh that is not as firm as that of other sport fish . additionally , white suckers contain large bones between their muscle segments that may render them unappetizing to some . still , they can be smoked , filleted , or ground into patties to produce tasty dishes .
according to this hypothesis , the sucker - footed bat fossils showed up right where scientists expected to find them : at the literal and figurative base of the noctilionoidea family tree .
white suckers are commonly confused with longnose suckers , which are related as bottom - feeding fish . both use fleshy lips to suck up organic material from the beds of rivers and streams as food and look very similar . the main difference between the two is that the longnose sucker has grey or dark , olive - colored sides .
citation hahn cm , iwanowicz lr , cornman rs , conway cm , winton jr , blazer vs . 2015 . characterization of a novel hepadnavirus in the white sucker ( catostomus commersonii ) from the great lakes region of the united states . j virol 89 : 11801–11811 . doi : 10 . 1128 / jvi . 01278 - 15 .
read pairs were quality screened and adapter trimmed prior to de novo assembly into contigs with clc genomics workbench , version 7 . as part of routine efforts to screen for contaminating sequences , blastx searches identified contigs with sequence similarity to hepadnaviruses , which we then culled from our white sucker transcriptome assembly , which is to be described elsewhere .
the discovery also shows that , like many island - dwelling , relict species , sucker - footed bats have not always been confined to their present range—they once swooped through the african skies .
it ' s impossible to know from the fossils if the extinct species had already evolved their characteristic sucker - feet , but the teeth shed light on another aspect of bat evolution . the presence of sucker - footed bats in africa at least 37 million years ago supports the theory that this family is one of the most primitive members of a lineage that now dominates south america .
(
status report on blue sucker ( cycleptus elongatus ) , a candidate endangered or threatened species
, 1993 ; eitzmann , et al . , 2007 ; yeager and semmens , 1987 )
u . s . fish and wildlife service . status report on blue sucker ( cycleptus elongatus ) , a candidate endangered or threatened species . north dakota state office : ecological services . 1993 .
male and female blue suckers change coloration during the spawning season . males also develop visible bumps on their heads during this time , so visual and tactile cues are likely important in blue sucker communication .
studies into the fish have focused on its life cycle , including reproductive abilities , how white suckers use their habitats and what types of prey they prefer .
for benthic invertebrate prey . removal of white suckers from areas with both species results in higher utilization of benthic invertebrates for food and lower consumption of zooplankton by yellow perch , which in turn increases the growth rate of adults . however , removal of white suckers does not significantly increase the population of yellow perch .
there are over one hundred species of suckers . the common or white sucker ( catostomus commersoni ) is a widespread species throughout much of northern and central north america . this species has a round mouth , useful for feeding on its usual prey of bottom - dwelling insects , crustaceans , molluscs , and other invertebrates . the common sucker is a relatively large species , attaining a length of up to 10 in ( 45 cm ) , and a weight of 2 . 2 lb ( 1 kg ) . the common sucker is often found in lakes and ponds . these fish generally run up nearby streams to spawn in gravel beds in the springtime , but they sometimes lay their eggs in gravel along shallow lakeshores . individuals of this species can live as long as 12 years .
what eats them ? white suckers are an important forage fish for several of minnesota ' s sport fishes . these include walleye , brook trout , muskellunge , northern pike , largemouth and smallmouth bass . additional predators are burbot and , in lake superior , sea lamprey . small white suckers also fall prey to fish - eating birds such as herons , loons , bald eagles , and osprey . many smaller white suckers are a much used bait in minnesota , and many are commercially harvested for that purpose .
white suckers are freshwater fish native to north america . they occur all across canada , from newfoundland and labrador to british columbia , as well as in the yukon and northwest territories and in all of the great lakes . they are found in both lakes and rivers , usually in shallow water where they feed on bottom on worms , clams , insect larvae and occasionally fish eggs . white suckers are robust and adaptable fish , surviving many adverse water conditions that other fish could not tolerate . this coupled with their high abundance and widespread occurrence has lead to the use of white suckers as environmental monitors for toxic chemicals and pulp mill effects , and various diseases including papillomas and liver tumours . they are not usually fished except for bait . white sucker serve as food for pike , muskellunge , bass , walleye , burbot , atlantic salmon , brook trout and a variety of birds and mammals .
white suckers occupy a wide range of habitats including streams , rivers , and lakes but are usually found in small creeks with cold , clear water and small or medium - sized rivers . white suckers are also highly tolerant of polluted , murky , and anoxic waters , as well as a wide array of stream gradients . they do not require dense vegetation and prefer temperatures between 11 . 8 and 20 . 6 degrees celsius . lethal ph for white suckers ranges from 3 . 0 to 3 . 8 .
the long slim body of the sharksucker is dark gray or dark brownish gray with a dark belly . there is a broad darker brown or dark gray stripe with white edges on each side that extends from the jaw to the base of the caudal fin with interruptions from the eyes and pectoral fins . the pectoral fins and ventral fins are black with or without a pale edge while the dorsal and anal fins are dark gray or black with white margins . the caudal fin is black with distinct white corners .
(
status report on blue sucker ( cycleptus elongatus ) , a candidate endangered or threatened species
, 1993 ; eitzmann , et al . , 2007 ;
species profile : minnesota department of natural resources
, 2012 )
(
status report on blue sucker ( cycleptus elongatus ) , a candidate endangered or threatened species
, 1993 ; daugherty , et al . , 2008 ;
species profile : minnesota department of natural resources
, 2012 )
the white sucker is quite adaptable . it has been collected from virtually all types of water in montana : muddy , clear , warm , cold , running and standing . as the position of the mouth suggests , it feeds on the bottom and eats an omnivorous diet of detritus and insects . the white sucker is distributed throughout montana ' s eastern drainage and is present in our northern watershed as well . they are most abundant in the many reservoirs of eastern montana . in montana the largest specimens have been about 5 pounds . large females can produce over 100 , 000 eggs and suckers can produce large populations in short periods of time . any type of attempted population control by man is usually a losing proposition . ( fwp ) see snyder and muth ( 1990 ) for a guide to the identification of larvae and early juveniles .
a 2010 study , overseen by the university of wyoming , found that white suckers readily hybridized with bluehead suckers and flannelmouth suckers in order to survive in a stream they weren’t native to .
white suckers can live in many different habitats including streams , rivers , and lakes but are mostly found in small creeks with cold , clear water and small or medium - sized rivers . white suckers are also very tolerant of polluted , murky , and oxygen poor waters . they do not need dense vegetation and prefer temperatures between 11 . 8 and 20 . 6 degrees celsius .
researchers at north dakota state university found in 2011 that white suckers have a size - selective approach to eating . the fish tend to pass up small organisms , instead going for larger prey .
white suckers have a long , round body and grow to a length of about 241 mm and a maximum weight of about 2 . 5 kg . they are olive brown to black on their back and lighter , or white on their belly , with dusky or clear fins . breeding males have a gold coloration on their backs and red ( or less commonly cream or black ) stripes across their sides . they have a toothless , sucking mouth and their lower lip is about twice as thick as their upper lip . white suckers have a shorter snout than their close relatives ,
white suckers have a long slender body and a dark back with silvery colored sides and a white belly . the dark coloration on the fish can vary - the most common color is yellowish - brown , but bright yellow , golden , and greenish variations exist . the mouth points down , allowing the fish to pick up food from the bottom . the head is rounded between the eyes .
the white perch is a close relative of the white bass and striped bass . the most recognizable trait of this silvery fish is its purple throat . it differs from silver bass in that it has a dark back . small worms are the best bait . they are usually found in six to eight feet of water near the bottom . the state record is three pounds , one ounce .
color is dusky olive brown to nearly black above , shading to cream or white below . dorsal fin has 11 to 13 rays . scales are medium sized , 60 to 75 in lateral line .
most species in the sucker family occur in the americas , over a range that extends from the boreal forest of north america through much of central america . a few other species occur in eastern siberia , and there is one isolated species in eastern china .
when they are spawning , male white suckers may show
head trembling
behavior , by vibrating their heads rapidly from side to side towards a nearby female or to other males in the area . males , however , do not compete with each other for mates . along with head trembling , male white suckers may also spread their pectoral fins , extend their dorsal fin , and stick out their jaw .
white sucker spawning and upstream breeding runs last for six weeks in the spring , or early summer in more northern regions . upstream breeding runs usually occur at night and spawning typically lasts from april to early may . this is timed to occur shortly after ice melts from a spawning area , the duration of spawning may be related to the water temperature . male white suckers reach the spawning area earlier than females and outnumber them . white suckers do not build nests or defend a territory . the spawning area usually has quick running water and a gravely substrate , but spawning can sometimes occur in lakes if conditions allow . males may show
head trembling
behavior ( vibrating their heads rapidly from side to side for a short time ) towards a nearby female who has come to rest at the bottom of a rapid . head trembling may also be directed at other males in the spawning area , although males do not fight for access to mates . along with head trembling , male white suckers also spread their pectoral fins , extend their dorsal fin , and protrude their jaw .
friedman’s research now gives us a richer hypothesis for how the remora got its sucker . some of the remora’s closest living relatives , like cobia , tag along with bigger fish to scavenge on their scraps . the ancestors of remoras may have lived a similar life .
in the spring , adult male white suckers develop a very distinctive black horizontal stripe . the coloration above and below the stripe lightens , and they develop hard bumps called tubercules on the tail and anal fin .
white suckers are highly underrated as a food fish . in the past , white suckers were passed over for other fish because of their many small , free - floating bones . but their flesh is firm and flaky , and their flavor sweet and delicious . there are several methods for getting around those bones , including grinding , canning , pickling , and scoring . check the recipes section for more info on eating suckers .
white suckers can be found throughout the northeast and midwest united states . they can also be found in portions of the upper northwest . they survive in rivers , streams and most any other type of water body .
white suckers are present in many habitats , from large windswept lakes to tiny , shallow streams . in small streams , white suckers are usually found in slower , deeper sections of the stream , though actively feeding fish often can be seen finning in the main channel . all good trout streams have healthy populations of white suckers - the young of which provide food for the largest trout in the stream . in larger rivers , white suckers roam the rocky flats or congregate in eddies and current breaks . in lakes , suckers often spend most of the year roaming the bottom in deep water . in the springtime , they migrate into streams connected to the lake to find spawning gravel . suckers spawn in shallow riffles . in some lakes , all the suckers in the lake may spawn on a single patch of sandy gravel where a trickle of water flows out .
white suckers are a very robust , common , and wide - ranging species with large population sizes and are therefore designated as a species of least concern according to the iucn red list . in a 1958 study focusing on the removal of the species , 12 , 750 white suckers were removed from a southern wisconsin stream over a 3 - year period . afterwards , it was estimated that 7 , 411 suckers still remained in the stream .
little is known about blue sucker behavior . observation in the wild is difficult due to swift currents and turbid waters that these fish inhabit . it it assumed that blue suckers hug the bottom of the main stem of river systems and wait for the current to bring food to them .
the adult worm - averaging 30mm in length and 13 mm in width , fasciola hepatica is one of the largest flukes in the world . the adult worm has a very characteristic leaf shape with the anterior end being broader than the posterior end and an anterior cone - shaped projection . the fluke possesses a powerful oral sucker at the end the anterior cone and a ventral sucker at the base of the cone which allow it to attach to the lining of the biliary ducts . each worm possesses ovaries and testes which are highly branched and allow for individual flukes to produce eggs independently .
during spawning , male white suckers may show
head trembling
behavior , vibrating their heads rapidly from side to side towards a nearby female , who rests at the bottom of a spawning area , or to other males in the spawning area . males , however , do not compete with each other for access to mates . along with head trembling , male white suckers may also spread their pectoral fins , extend their dorsal fin , and protrude their jaw .
, and midge larvae carried to them by currents . as white suckers mature , their mouthparts move to their underside , allowing them to bottom - feed . as adults , they feed additionally on fish , fish eggs , plants ,
, and midge larvae carried to them by currents . as white suckers age , their mouthparts move to their underside , allowing them to bottom - feed . as adults , they also feed on fish , fish eggs , plants ,
importance we report the first full - length genome of a hepadnavirus from fishes . phylogenetic analysis of this genome indicates divergence from genomes of previously described hepadnaviruses from mammalian and avian hosts and supports the creation of a novel genus . the discovery of this novel virus may better our understanding of the evolutionary history of hepatitis b - like viruses of other hosts . in fishes , knowledge of this virus may provide insight regarding possible risk factors associated with hepatic neoplasia in the white sucker . this may also offer another model system for mechanistic research .
as north american bats face a death toll approaching 7 million , university of akron scientists reveal new clues about their killer , white nose syndrome , or wns . the ua researchers reveal that the deadly wns fungus can likely . . .
) . to avoid the inclusion of pgrna or viral mrna in the genome model , we isolated dna from an ethanol - preserved liver . resequencing was conducted on a single , pcr - positive fish collected from the root river ( white sucker hepatitis b virus [ wshbv ] rr173 ) . the dna was extracted using a dneasy kit ( qiagen , valencia , ca ) as per the manufacturer ' s protocols . primers were designed to resequence the complete genome and confirm a circular architecture . we used primer3 , version 2 . 3 . 4 (
white suckers eat mostly insect larvae , just like trout do , so a wide variety of trout flies will work very well for white suckers . white suckers use their keen eyesight to hunt down free - floating prey to a greater extent than most species of suckers . but while trout sometimes feed on insects anywhere in the water column , white suckers concentrate on insects that are on , or very close to , the bottom . so let’s say you’ve found yourself a fine pod of large white suckers in a nice section of water , or a good pool that looks like it should hold some . what’s next ? in my opinion , any rig that gets the fly down to the fish and moves it along drag - free will work . for many people , this is a shot - and - indicator rig . others forego the indicator and fish by feel . both methods will work , as long as the fly is traveling right along the bottom at the same speed as the current . my favorite tactic is to fish an indicator rig directly upstream or slightly across , allowing the offering to drift down through the school of suckers . the take of a white sucker is very subtle . if using an indicator , watch it closely . the indicator will either pause or dip for a fraction of a second before the fish spits out the fly . suckers have an amazing sense of taste and will reject a fake insect almost instantly . if not using an indicator , you’ll need to develop a sixth sense to detect strikes . wait for a slight hesitation in drift , a slight increase or decrease in tension , or a small tap on the line . in either case , you must strike quickly , but softly , to avoid breaking your tippet .
white suckers have a long , round body and grow to an average length of 241 mm and a maximum weight of about 2 . 5 kg . they have olive brown to black coloration on their back and a lighter colored , or white belly , with dusky or clear fins . breeding males gain gold coloration on their backs and red ( or less commonly cream or black ) stripes across their sides . they have a toothless , sucking subterminal mouth with no barbels . the mouth region is additionally characterized by thick pappilose lips , with a lower lip that is about twice as thick as the upper lip . white suckers have fewer lateral line scales ( between 55 and 58 ) and a shorter snout than their close relatives ,
suckers are a main food item of osprey and eagles . they are fun to fish for and although few people have tried them , they are excellent to eat . they have firm , white , light - tasting meat , especially during spring .
transmission electron micrographs showing both complete virions of approximately 40 nm in diameter and smaller particles assumed to be composed of self - assembled virus surface proteins . the two types of particles from gradient - purified white sucker serum have a strong resemblance to those of other hepatitis b - like viruses from mammals and birds . virus was stained using 1 % phosphotungstic acid ( a ) and 0 . 5 % uranyl acetate ( b ) . scale bar , 100 nm . images were processed using adobe photoshop and included the adjustment of brightness and contrast and application of the unsharp mask filter .
young white suckers , up to about 10 cm in size , are light brown or beige coloured and have three , very distinct , dark spots on their sides : one behind the gill plate , another about mid body and the third before the tail .
embryos of white suckers develop quicker in warmer temperatures . organs begin developing the day eggs are fertilized . soon afterwards , the embryo becomes mobile , develop a circulatory system , and grow longer . larvae hatch after about 5 to 7 days and are 21 to 25 mm in length , with slanted mouths and short intestines . when white suckers are less than 51 mm long , they feed in shallow water , 15 to 20 cm deep and along lake shores . in some populations , white suckers are mature by the time they are 2 years old , however , on average , suckers are mature by age 3 . in other populations , males mature at a faster rate ( 2 years old ) than females ( 3 years old ) but all are mature by age 4 .
white suckers spawn and breed upstream for six weeks in the spring , or early summer in northern areas . upstream breeding usually happens at night and spawning usually lasts from april to early may . this happens shortly after ice melts from a spawning area , the length of spawning may be related to the water temperature . male white suckers reach the spawning area earlier than females and outnumber them . white suckers do not build nests or defend a territory . the spawning area usually has quick running water and a gravely substrate , but spawning can sometimes occur in lakes if conditions are correct . males may show
head trembling
behavior ( vibrating their heads rapidly from side to side for a short time ) towards a nearby female who has come to rest at the bottom of a rapid . head trembling may also be directed at other males in the spawning area , although males do not fight for mates . along with head trembling , male white suckers also spread their pectoral fins , extend their dorsal fin , and stick out their jaw .
white suckers have long , round bodies with light - colored underbellies and darker - colored sides , usually splashed with a dark green , grey , copper or black . their fins are rayed in a similar fashion to other cypriniform fishes , like carp and chub .
today , the sucker - footed bats consist of two species , myzopoda aurita and m . schliemanni , endemic to madagascar . in contrast to almost all other bats , they don ' t cling upside - down to cave ceilings or branches . sucker - footed bats roost head - up , often in the furled leaves of the traveler ' s palm , a plant in the bird - of - paradise family . to stick to such a smooth surface , the bats evolved cup - like pads on their wrists and ankles . scientists previously suspected the pads held the bats up by suction , but recent research has demonstrated the bats instead rely on wet adhesion , like a tree frog .
assessment of the presence of wshbv dna in white sucker from the root river ( racine , wi ) via endpoint pcr identified a prevalence of 20 % among sampled fish ( n = 20 ) . the prevalence of virus was not statistically different from that observed at the geographically proximate milwaukee river site ( fisher ' s exact test , p = 0 . 3 ) . we detected viral dna in the plasma samples from the same four root river individuals that were positive by pcr ( data not shown ) . absence of amplicons from numerous individuals confirmed that this pcr primer set does not amplify an endogenous viral relic .
how big do they get ? how long do they live ? white suckers in minnesota normally grow to about 300 mm ( 20 in ) and weigh in at about 0 . 9 - 1 . 4 kg ( 2 - 3 lbs ) . lunkers can go 2 . 3 kg ( 5 lbs ) . minnesota ' s hook and line record for this fish is 4 . 12 kg ( 9 lbs 1 oz ) . it was caught in big fish lake in stearns county . white suckers typically live for about 10 - 12 years .
instead of being used as food for humans , white suckers commonly are used as bait for bigger and more prized game fish . this occurs when they are still small and appear similar to minnows . if they are eaten by humans , they are normally processed and sold as mullets .
embryonic development of white suckers is faster in warmer temperatures . organs begin developing on the same day as fertilization , indicated by the formation of a head region . soon afterwards , the embryo becomes mobile , develops its circulatory system , and increases in length . their larvae hatch after about 5 to 7 days and are 21 to 25 mm in length , with slanted mouths and short intestines . when white suckers are less than 51 mm in length , they tend to feed in shallow water , 15 to 20 cm deep and along lake shores . in some populations , white suckers are mature by the time they are 2 years old , however , on average , suckers are mature by age 3 . in other populations , males mature at a faster rate ( 2 years old ) than females ( 3 years old ) but all are mature by age 4 .
a team of researchers described the two bat species from several sets of fossilized jawbones and teeth unearthed in the sahara . the findings , reported feb . 4 in the open - access journal plos one , represent the first formal description of the family in the fossil record and show the sucker - footed bat family to be at least 36 million years older than previously known .
white suckers can be caught on just about any tackle . the most effective method is light or ultralight spinning tackle . four to six pound test monofilament should be used , along with small , sharp hooks . worms or live aquatic nymphs are the best baits for suckers . fish directly on the bottom , either with a stationary rig with a sliding sinker , or with a drifting rig that moves along the bottom with the current . white suckers can be light biters , so a sensitive rod and light line is a good choice . using a bankstick helps detect the lightest bites .
a study from the u . s . epa found that the fish’s growth is affected by temperature changes of water . levels of low light are also advantageous to the fish’s development , with better growth rates seen in white suckers who had been exposed to low light rather than no light at all .
) are a highly ubiquitous species . their range is over 2 . 5 million square kilometers , stretching from east of the mackenzie river to labrador in canada , and into 40 states in the eastern and midwestern united states . white suckers are also an introduced species in the colorado river drainage basin .
, and algae . however , their feeding pattern is nonrandom . adult white suckers feed primarily on zooplankton and benthic invertebrates with mild seasonal variation , but they may also specialize in one or the other as a form of resource partitioning , or selectively feed on the largest individuals if resources are abundant .
the northern redhorse or redfin sucker ( moxostoma macrolepidotum ) occurs widely in central north america . the lake or northern chub ( couesius plumbeus ) is a small minnow - sized fish that occurs widely across northern north america . this is an important forage and bait fish . the lake chubsucker ( erimyzon sucetta ) occurs in the eastern united states , including lake saint clair and lake erie .
hepatocellular carcinoma is associated with hbv infection in humans . hepatic tumors are not uncommon in white sucker inhabiting the great lakes regions , and prevalence of this pathology is used as an indication of contaminant exposure . liver tissue preserved in z - fix ( anatech ltd . , battle creek , mi ) was therefore processed for histopathological observation via graded alcohols , paraffin infiltration , and embedding . tissues were sectioned at 5 μm and stained with hematoxylin and eosin . hepatic tumors included hcc , hepatic adenoma ( ha ) , cholangioma ( co ) , and cholangiocarcinoma ( cc ) . tumor and virus data were converted to a binary data set , and jaccard binary dichotomy coefficients were determined to evaluate dissimilarity .
today , madagascar sucker - footed bats live nowhere outside their island home , but new research shows that hasn ' t always been the case . the discovery of two extinct relatives in northern egypt suggests the unusual creatures , which evolved sticky footpads to roost on slick surfaces , are primitive members of a group of bats that evolved in africa and ultimately went on to flourish in south america .
the fry of white suckers eat plankton and other tiny invertebrates until they are about 15 mm long . up to this size their mouths still point forward to accommodate catching food up in the water column . once they reach 15 mm , their mouths rotate downward and they switch to the adult habit of bottom feeding .
suckers are a family of freshwater fishes ( the catostomidae ) that includes about 65 species worldwide , with most of these in north america . they ' re all fairly robust or stout fishes , with species ranging in size from small ( about 15 cm ) to large ( up to 45 cm ) in length . nearly all species in the family have the characteristic downward - pointing
sucker
mouth .
how do they reproduce ? the spawning season in minnesota for the white sucker begins in april and goes into early may . the fish move to the shallows of the lakes or up into stream headwaters unless a barrier stops them . once there they pick spots that have a gravel or coarse sand bottom . there is no nest made and the eggs go without care from the parents . the white suckers pair up , usually two males to one female . the spawning normally takes place at night , starting at dusk . with a male on either side of her , the female begins to lay her eggs while males fertilize them . the eggs are spread out by the current and the movement of the fish . eventually they sink to the bottom . depending on her size , a female will lay 20 , 000 - 50 , 000 eggs during the complete spawning period . the embryos develop for 5 - 10 days before they hatch , depending on water temperature . it takes another 1 - 2 weeks before they leave the gravel and drift downstream .
white suckers reproduce in shallow waters and are believed to be influenced by changes in water temperature to begin the process . this can be caused by runoff from early snow melt or other factors . females of the species lay near 10 , 000 eggs and it is not uncommon for them to be fertilized by multiple males .
white suckers primarily spawn in the spring , usually early may to early june . adults migrate from lakes into gravelly streams , when stream temperatures reach 10 o c . spawning sites are in shallow waters with a gravel bottom adults will return to specific spawning site ; thousands may migrate to the site at a particular period .
scientific name :
catostomus
is from the greek ,
kata
, meaning downward , and the greek
stoma
, meaning mouth . so
catostomus
is clearly a reference to the downward pointing mouth of a sucker . the specific name ,
commersonii
is from the fish being named for an early french naturalist : philibert commerson . ( thanks go to adam labatore , for pointing this out ! )


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 .