Species Accounts - Gobiidae - Knipowitschia
Genus Knipowitschia
Il'in, 1927
This genus of sand gobies has about 13 species in the Caspian, Black, Aegean and Adriatic seas and adjacent fresh waters with 2 recorded from Iran. Later spelt Knipovitschia, incorrectly, in the English summary of Il'in's 1928 description. The original description is apparently in Il'in (1927d) (as is that of Caspiosoma) but was repeated in Il'in (1928). Hyrcanogobius Il'in, 1928 and Bubyr Il'in, 1930 are synonyms (Economidis and Miller, 1990) although Miller in Miller (2004) separates Hyrcanogobius.
The body is fusiform without a strongly depressed head, the dorsal profile anteriorly being straight. The mouth angle does not reach past the anterior part of the eye. The mouth is oblique. The eyes are moderate in size and may be lateral or directed upwards. The body usually bears imbricate ctenoid scales but the head is naked as can be the anterior part of the back as far as the second dorsal fin and the middle of the abdomen to the anal fin. There may be axillary scales and scales on the belly midline. Some members lack scales except for the axillary region and the caudal peduncle. Lateral series scales less than 40. There are no barbels and the anterior nostrils are not an extended tube-like structure. The posterior nostrils are pore-like. The nape lacks a bony crown and only the posterior part of the cranium is covered with dorsal muscles. The preoperculum lacks teeth or projections. The isthmus is broad and the branchiostegal membrane is attached to its entire lateral margin. Jaw teeth are conical, caniniform and in several rows forming a band. The outer row is slightly enlarged but there are no strongly enlarged teeth. The vomer lacks teeth. The tongue is truncated or slightly rounded. The gill rakers are small and broadly spaced apart. The pectoral fins lack fine, silk-like rays. The anterior edge of the pectoral girdle lacks dermal flaps. The pelvic fin disc reaches to, or near to, the anus. The pelvic fin anterior membrane is well-developed but without obvious lateral lobes. The caudal peduncle is slender and longer than the second dorsal fin base. The upper angle of the caudal fin is nearly rectangular and the caudal fin is rounded and shorter than the head. The head canals are variably developed or absent, and may be damaged by abrasion in poorly preserved material. The first dorsal fin modally has 6 or 7 rays and vertebral modes are 30-33. The swimbladder is present or reduced. There is no perianal organ. Colour is light. Postlarvae are planktonic.
Miller in Miller (2004) also defines this genus by characters of the head lateral line system, namely having the infraorbital longitudinal row a present with typically at least 2 transverse rows from this row; transverse infraorbital rows between levels of rows b and d along cheek, with rearmost descending behind posterior end of row d; transverse row behind jaw angle not descending below level of row d; row b short, to below rear eye; anterior row tra distant from row b; anterior dorsal row g distant from row n; snout rows r and s linear; uniserial row of papillae along upper edge of each orbit when canals are absent but never with transverse rows; anterior oculoscapular canal (if present) ending anteriorly in interorbit, dividing from pore κ to end at double pores β; posterior oculoscapular present or absent; and preopercular canal when present always lacks middl;e pore δ.
Vasil'eva and Kuga (2001) propose that the separation of Knipowitschia from Pomatoschistus is doubtful based on similar cranial osteology and the variation in the degree of development of head canals seen in Knipowitschia. However Miller in Miller (2004) disagrees and presents arguments for a "sand-goby" group of 5 distinct genera, of which only Knipowitschia and Hyrcanogbius are known from Iran (Pomatoschistus, Gobiusculus and Economidichthys being the others).
Miller (1990) states that the majority of the members of this genus evolved after the draining of the Western Paratethys basin into the Adriatic Sea basin in the late Miocene about 6.0-5.5MYA.
Members of this genus are called gav mahi and سگ ماهي (sag mahi) in Farsi and this not repeated under each species account.
Knipowitschia caucasica
(Kavraiskii in Berg, 1916)
Common names
gel-ye mahi qafqazi (= Caucasian goby) or gavmahi-ye qafqazi.
[gafgaz xulu in Azerbaijan; bubyr kavkazskii in Russian; Caucasus bald goby; Caucasian dwarf goby].
Systematics
Pomatoschistus caucasicus was originally described from Batumi/Temirgoe, a station south of the Sulak mouth on the Black Sea.
The name of this species first appeared in Kavraiskii in Radde (1899) as a museum name without a description ( a nomen nudum) and was subsequently made available by L. S. Berg in 1916 with the type locality being a swamp near Batum and Lake Inkit near Pitzunda, Georgia (see Eschmeyer (1990) and Eschmeyer et al. (1996) for details).
Gobius lenkoranicus Kessler, 1877 described from "pribrezhnom' bolote, po blizosti Lenkorana" (= a coastal marsh near Lenkoran, Azerbaijan) is a synonym, tentatively so according to Economidis and Miller (1990). This name was suppressed by the International Commission on Zoological Nomenclature (see Kottelat, 1997; Miller et al. in Miller, 2004)). This earlier name for what could be caucasica was suppressed as a nomen dubium because of an inadequate original description in its details and the small and poorly-preserved holotype which could not be readily compared with caucasica. The name could also have been suppressed as a nomen oblitum as it had not been used for 50 years (Economidis and Miller, 1990).
Formerly placed in the genus Pomatoschistus Gill, 1863 and in the genus Bubyr Il'in, 1930.
Three syntypes from Lake Temirgorje, Georgia (formerly in the Tiflis Museum) are in the Natural History Museum, London under BM(NH) 1896.3.28:26-28 (22.1-25.2 mm standard length) (Eschmeyer et al., 1996; personal observations). Economidis and Miller (1990) list these three specimens (as evidenced by the catalogue numbers 26-28) as two males (22.8-24.0 mm standard length) and two females but give the length of only one female (24.5 mm). Miller et al. in Miller (2004) consider the material used by L. S. Berg (see above) to be the type series (ZISP 15343 from Lake Inkit and ZISP 15321 a swamp near Batum).
Key characters
The anterior oculoscapular lateral line head canals unite in the posterior interorbit, with a single median pore κ, and canals extend anteriorly to pores λ. The preopercular canal is present (Miller in Miller, 2004).
Morphology
First dorsal fin with 5-8, usually 6, spines (rarely 4 as an anomaly, e.g. in Berg (1948-1949, Fig. 784 (Il'in, 1956)), second dorsal fin with 1 spine and 6-10 branched rays, usually 7-8, anal fin with 1 spine and 5-10 branched rays, usually 7-8, and pectoral fin with 13-18 rays. Lateral scales 29-38. Vertebrae 30-33. The back in front of the first dorsal fin and the belly in front of the anal fin are usually scaleless. The caudal peduncle is completely scaled and there is a complete row of scales anteriorly along the lateral midline, although other flank scales may be missing. The anterior oculoscapular head lateral line canals join in the posterior interorbit region, with one pore κ, and paired canals in the interorbit each to a pore λ and single pore α. The posterior oculoscapular canal is typically present, the preopercular canal is present and there are no additional pores on the horizontal anterior oculoscapular canal behind the eyes (
Miller et al. in Miller, 2004). The subopercular canal is variably present which has led to different generic assignments for this species. The larva has been described by Daoulas et al. (1993).Meristic values for Iranian specimens are:- first dorsal fin spines 6(4), second dorsal fin rays after a spine 6(1) or 8(3), anal fin rays after a spine 8(2) or 9(2), lateral scales 33(1), 34(1), 36(1), 39(1), and total gill rakers 9(3) or 10(1). Rakers are very short, not reaching half way to the adjacent one when appressed.
Sexual dimorphism
See under colour. Males are larger than females. There are various morphometric differences (Miller et al. in Miller, 2004).
Colour
Overall colour is grey to fawn with olive-green tints. Fish in hypersaline habitats are darker. Males are generally darker than females and have distinct dark bars on the flanks below the two dorsal fins and on the caudal peduncle while females have irregular spots or blotches along the flank mid-line. Nuptial males have 4 prominent bars. However some males may lack bars and have spots and some females lack spots (Ahnelt et al., 1995). The head in males is densely pigmented, including ventrally. The caudal peduncle is completely pigmented, usually including the ventral surface. The flank bar under the first dorsal fin in males is long and usually runs from near the dorsal mid-line to the belly. The male first dorsal fin has three oblique dark bands and a dark spot medially on rays 5 and 6 extending posteriorly on the fin membrane. The distal edge of this dorsal fin is dark. The second dorsal fin has three bands also and a dark edge. Males have dark pigment on the pelvic fins, head and breast, and a silver hue on the anal fin during the breeding season. The male pectoral fin has a short and oblique dark band on the upper rays. The anal fin in males is normally dark with a pale margin while in females it is pale overall. The caudal fin has thin dark bands.
Females are a pale fawn overall. The female has a densely spotted first dorsal fin while the male has a blue blotch at the fin rear when in breeding condition. The first dorsal fin in females has a distinctive middle band but the others are faint. The second dorsal fin in females is only faintly banded. Breeding females have 2 intensely black areas on the first dorsal fin, a black spot on the lower jaw, 2 rows of melanophores running obliquely from the eyes to the upper jaw, and a yellow abdominal region (Economou et al., 1994). The back has fine melanophores extending to the rear of the second dorsal fin. There are light saddles at the origins of the first and second dorsal fins, the end of the second dorsal fin and on the caudal peduncle. The mid-flank has several blotches, some slightly deeper than wide. The rest of the body below these blotches is pale except for some short vertical groups of melanophores below the lateral midline and melanophores along the base of the anal fin. The breast is pale as opposed to dark in males.
Large and minute pigment blotches and spots variably developed are scattered over the whole head and body in both sexes of an Iranian sample. The peritoneum has large pigment spots ventrally or is almost immaculate.
Size
Reaches 48.6 mm, perhaps 69 mm, total length. Fish in Gorgan Bay reached 46 mm (Afraei and Hassannia, 1999).
Distribution
Found in the Aegean, Black and Caspian Sea basins. Introduced to the Aral Sea. Caspian localities include Imeni Kirova or Kyzylagach Bay near the northwestern Iranian border, the lower Safid River and lower Babol River, near Anzali and Ashuradeh (Derzhavin, 1934). It is reported from Gorgan Bay, the delta of the Karasu, the Atrak River, the southeast Caspian Sea, southwest Caspian Sea and south-central Caspian Sea (Kiabi et al., 1999; Jolodar and Abdoli, 2004; Miller et al. in Miller, 2004).
Zoogeography
This species is part of marine fauna in the eastern Mediterranean and the Black-Caspian-Aral seas basins and its relationships are outlined under the genus description above.
Habitat
This species lives and reproduces in salinities as high as 59.5‰ and up to 83‰ (Zenkevitch, 1963; Miller et al. in Miller, 2004) but also enters fresh water. Preferred conditions in the Aegean area are 15-20‰ (Ahnelt et al., 1995; Miller et al. in Miller, 2004). Juveniles prefer sand, mud or gravel bottoms near shore in Greece (Daoulas et al., 1993) but weedy shallows are also favoured (Economidis and Miller, 1990). They may overwinter in deeper water at 1-2 m in the Volga delta (Economidis and Miller, 1990) and migrate into shallow water in April-May prior to spawning (Miller et al. in Miller, 2004). The Atrek River population moves downstream (Miller et al. in Miller, 2004).
Age and growth
Life span may be only 1 year and as a consequence numbers can fluctuate widely in any given year depending on environmental conditions. In the Evros Delta of the north Aegean Sea, fish grow rapidly during the summer after hatching, breed from the end of April to the end of July in the following summer and grow rapidly again from July to September. Older males die the following year after February but some females will survive to spawn a second time at the end of April and the beginning of May and then die. Fish may be mature at 14.5 mm total length (Kevrekedis et al., 1990). In the spawning season, females comprise as much as 85.5% of the population (Miller et al. in Miller, 2004).
A study of this species in Gorgan Bay, Golestan (Iranian Fisheries Research Organization Newsletter, 23:2, 2000) showed that the maximum size obtained was 46 mm with average lengths of 33 and 37 mm for males and females respectively. The sex ratio was 1:1.1 for males to females (see also Afraei and Hassannia (1999)). In the Volga delta spawning males were 33.3 mm and females 30.2 mm on average (Miller et al. in Miller, 2004).
Food
Diet was dominated by polychaete worms and chironomids (88%) in one study but crustaceans such as amphipods, copepods, ostracods, cladocerans, insects such as choronomids, bivalve mollusc larvae, and fish are also taken and items may be both benthic and planktonic.
Reproduction
Females may be carrying eggs at 20-24 mm and 8-10 months of age. Fecundity reaches 1389 eggs but can be as low as 60 eggs. Fecundity in the Caspian Sea ranges from 209 to 786 eggs with a mean of 423, from 209 to 382, mean 285 and from 527 to 863, mean 715.6 for various reports (Kevrekedis et al., 1990). Batches consist of 80-100 eggs. Eggs are cylindrical, 2.6 x 0.97 mm. Larvae are pelagic and as small as 4.1 mm standard length. Relative fecundity in the Gorgan Bay study in Iran was 290-550, mean 395.5 eggs.
There is a pre-spawning migration into shallow water in April in the Caspian Sea. The male approaches the female from below, touching her lower jaw with his snout and leading her to a reed nest. Such behaviour occupies several hours to more than a day. The female enters the reed nest, inverts and deposits eggs on the roof of the nest. The underside of bivalve shells or gravel may also be used. The male then fertilises the eggs, inverting to do so. The eggs are laid in a line and the pair will form other lines. Egg patches may eventually contain as many as 3000 eggs at different developmental stages, which indicates males may spawn with several females. Spawning takes about 1.5 hours and the female gradually loses the brightness to her breeding colours and almost all breeding pigment is lost within a day. The pair mated 4 times over a period of 35 days (28 March, 6 April, 14 April and 2 May in an aquarium with fish from Lake Trichonis, Greece). The male remains mostly inside the reed nest, aerating the eggs and defending them against other gobies. At irregular intervals (8-60 minutes), the male would leave the nest for 1-5 minutes, occasionally feeding but always remaining near the nest.
Spawning in the pre-estuary area of the Volga River in the Caspian Sea takes place from the middle of April to the end of May, rarely to June. Spawning in the Caspian takes place in shallow water with some current at a depth of 0.15 to 1.5 m, a temperature of 15-27°C and over a wide range of salinities (Kevrekedis et al., 1990).
Parasites and predators
None reported for Iran.
Economic importance
None.
Conservation
This species seems to be rare in Iran with only Derzhavin's (1934) report and one other record. Its status cannot be assessed until more is known about its distribution. Kiabi et al. (1999) consider this species to be data deficient in the south Caspian Sea basin according to IUCN criteria. Criteria include abundant in numbers, habitat destruction, limited range (less than 25% of water bodies), absent in other water bodies in Iran, absent outside the Caspian Sea basin (sic). Vulnerable in Turkey (Fricke et al., 2007).
Further work
Further collecting will need to be carried out to determine its abundance and distribution in Iranian waters. Its small size may have led to it being ignored or confused with other gobies as young and it may be more widely distributed than current knowledge indicates.
Sources
Iranian material: Uncatalogued, 4, 22.2-35.3 mm standard length, Mazandaran, Gorgan Bay (no other locality data).
Knipowitschia iljini
Berg, 1931
Common names
gavmahi-ye Iljin, gel-ye mahi.
[Il'in's bychok in Russian, Iljin xulu in Azerbaijan].
Systematics
At least 4 syntypes are in the Zoological Institute, St. Petersburg (ZISP 22052) along with ZISP 24370 and possibly ZISP 24424 (Miller and Pinchuk in Miller, 2004). Although Berg (1931b) states "many specimens caught" this may refer to abundance while only 4 fish are illustrated and may be the type series. This species was described from "in the middle part of the Caspian Sea".
Key characters
The anterior oculoscapular lateral line head canals are more or less separate in the midline of the posterior interorbit, with double or separate pores κ, and canals extend anteriorly through interorbit of variable extent. The preopercular canal is absent or present (Miller in Miller, 2004).
Morphology
The first dorsal fin has 6-8 spines, usually 7, the second dorsal fin has 1 spine followed by 8-10 soft rays, the anal fin has 1 spine and 7-10, usually 9, soft rays, the pectoral fin has 15-18 rays. Lateral series scales 28-38. Vertebrae 31-33. Scales are ctenoid. The belly, head and the dorsal surface back to the second dorsal fin are all naked. There is no small, straight canal extending posteriorly from the junction of the orbital canals. The caudal fin is rounded and symmetrical. The anterior oculoscapular lateral line head canals do not unite in the posterior interorbit. Canals anterior to pores κ are typically absent and pore κ is double. The posterior oculoscapular canal is absent, the preopercular canal absent or present. Pore "a" is single or double with sometimes an additional pore or two on horizontal anterior oculoscapular canal behind eye.
Sexual dimorphism
Males have darker overall colouration and darker fins than the females (see below). The first dorsal fin in males has free tips and usually a dark spot at the rear margin. Males have a pointed genital papilla while females have a distally bifurcated papilla. The pelvic fins reach the genital papilla in males while in females they do not reach the vent. Females have a more slender caudal peduncle and the snout is more produced than in males.
Colour
The body overall has a brownish reticulate pattern. The back and flanks bear about 6-10 dark bands in males while in females bands are faint and restricted to the posterior flank. The male has a darkly edged caudal fin and the pectoral fin is dark ventrally. The dorsal fins have dark stripes and the anal fin has a dark stripe along its margin in males while females lack stripes. Females bear small dark spots irregularly distributed on the back and anterior flanks.
Size
Attains about 4.7 cm for males and 5.0 cm for females. Ragimov (2003) gives a maximum length of 5.2 cm.
Distribution
Ragimov (1965) reports this species between Kultuk and Astara in Azerbaijan and generally in the central and southern Caspian Sea, and mapped around the coast of the whole Caspian by Miller and Pinchuk in Miller (2004).
Zoogeography
This species is part of a marine fauna in the eastern Mediterranean and the Black-Caspian-Aral seas basins and its relationships are outlined under the genus description above.
Habitat
Found benthically and in the water column with adults in shallow coastal areas at 20-70 m with juveniles offshore as deep as 500 m Not recorded from fresh water.
Age and growth
Life span is estimated at one year (Miller and Pinchuk in Miller, 2004).
Food
Only mysids have been recorded from 8 fish examined (Miller and Pinchuk in Miller, 2004).
Reproduction
Gonad maturity begins in late August to early September, many fish are ripe by the end of January and most by the end of February. Spawning occurs from early April to possibly as late as September with a peak in May-June (Miller and Pinchuk in Miller, 2004). Fecundity reaches 2240 eggs and egg diameter 0.8 mm (Miller and Pinchuk in Miller, 2004).
Parasites and predators
None reported from Iran but sturgeon and Sander species eat this fish (Miller and Pinchuk in Miller, 2004).
Economic importance
None.
Conservation
Apparently rare in Iran but this may reflect collecting effort for this small species. Insufficient work has been devoted to this species to assess its status.
Further work
Further collecting will need to be carried out to determine its abundance and distribution in Iranian waters. Its small size may have led to it being ignored or confused with other gobies as young and it may be more widely distributed than current knowledge indicates.
Sources
Iranian material: None.
Knipowitschia longecaudata
(Kessler, 1877)
Black and Caspian seas, described from the southern and middle Caspian Sea, but no Iranian record. Ragimov (1965) reports this species between Kultuk and Astara in Azerbaijan. Sometimes spelt longicaudata erroneously in the literature.
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