Gobiidae, sensu Gill & Mooi, 2012

Zarei, Fatah, Esmaeili, Hamid Reza, Abbasi, Keyvan, Kovačić, Marcelo, Schliewen, Ulrich K. & Stepien, Carol A., 2022, Gobies (Teleostei: Gobiidae) of the oldest and deepest Caspian Sea sub-basin: an evidence-based annotated checklist and a key for species identification, Zootaxa 5190 (2), pp. 151-193 : 183-185

A key to the native Gobiidae of the South Caspian Sea sub-basin

1a. head canals absent; no real scales on the body, the body naked or covered with bony tubercles and/or granules........... 2

1b. head canals present; body with ctenoid and/or cycloid scales.................................................. 20

2a. first dorsal fin with usually VI rays, the sixth ray at an increased distance from the fifth; body naked or partly covered with non-overlapping ctenoid scales.......................................................................... 3

2b. first dorsal fin with I–IV rays; body covered with bony tubercles and/or granules, naked only in sexually mature males..... 4

3a. coloration uniformly pale, living individuals almost transparent; no bands on the body; body naked; second dorsal branched rays 14; anal fin branched rays 11–12............................................... Benthophiloides turcomanus

3b. coloration brownish, living specimens normally pigmented; dark vertical or oblique bands on the body; immature individuals with small non-overlapping scales on the sides; second dorsal branched rays 11–13; anal fin branched rays 9–11........................................................................................... Benthophiloides brauneri

4a. head narrow (head width less than 55% of its length), snout elongate and duck-bill shaped; eight transverse suborbital rows of neuromasts, six in front of suborbital longitudinal row b; chin barbel absent; no dermal fold behind jaws................................................................................................ Anatirostrum profundorum

4b. head broad (head width more than 70% of its length); snout not elongate and duck-bill shaped; seven transverse suborbital rows of neuromasts, four in front of suborbital longitudinal row b; most species with chin barbel and dermal fold behind jaws... 5

5a. no tubercles; only densely-set bony plates of different size on head and body, embedded in skin and lacking apex, not arranged in regular rows....................................................................................... 6

5b. tubercles possessing distinct apex and not embedded in skin, arranged in 2 main and 1–2 additional longitudinal rows on each side of body........................................................................................ 10

6a. head with medial groove on temporal and occipital regions; thorny granules on rays of first dorsal fin.................. 7

6b. head not grooved; no thorny granules on rays of first dorsal fin................................................. 9

7a. second blotch circular; no enlarged bony plates in front of second dorsal fin....................... Benthophilus grimmi

7b. second blotch band-shaped, descending obliquely on flank; several enlarged flat bony plates at origin of second dorsal fin, each surrounded by smaller plates............................................................................ 8

8a. horizontal eye diameter, 12–16 % HL, less than interorbital distance, 16–21 % HL; periorbital row of enlarged granules along upper eye margin; no granules on eye................................................... Benthophilus svetovidovi

8b. horizontal eye diameter, 17–22 % HL, considerably larger than interorbital distance, 7–13 % HL; no periorbital row of enlarged granules; granules on eye present........................................................ Benthophilus kessleri

9a. no bony plates on belly and flanks; no dark blotches on body.............................. Benthophilus leptorhynchus

9b. bony plates on belly and flanks; three dark blotches on back................................ Benthophilus granulosus

10a. no tubercles on upper head surface or upper head tubercles present only on snout and between eyes................... 11

10b. tubercles on upper head surface present, including temporal and occipital regions................................. 15

11a. dorsal row of tubercles incomplete, starting at first dorsal-fin’s origin........................................... 12

11b. dorsal row of tubercles complete, starting just behind head................................................... 13

12a. dermal fold at angle of mouth well-developed........................................... Benthophilus ctenolepidus

12b. dermal fold at angle of mouth absent................................................. Benthophilus leptocephalus

13a. dorsal row of tubercles 22–29.......................................................... Benthophilus persicus

13b. dorsal row of tubercles 30–33.......................................................................... 14

14a. medial groove on head deep and well-developed on temporal and occipital regions; granules few and scattered, absent from medial groove; anterior-most tubercles of dorsal row of similar size as others in the row; ventrolateral row absent or with only few tiny tubercles.................................................................... Benthophilus pinchuki

14b. medial groove on head very shallow, if well-developed then only between eyes; granules densely-set on entire upper head surface including medial groove; several anterior-most tubercles of dorsal row smaller than following ones; ventrolateral row with 16–19 tiny tubercles.............................................................. Benthophilus ragimovi

15a. no medial temporal tubercle; dorsal row tubercles 11–24; ventral-row tubercles 9–20; total vertebrae 24–27, commonly 25–26; anal-fin segmented rays 5–7, commonly 6................................................................. 16

15b. medial temporal tubercle present; dorsal-row tubercles 23–31; ventral-row tubercles 19–26; total vertebrae 27–31; anal-fin segmented rays 6–10, commonly 7–9.................................................................... 17

16a. first dorsal-fin spines 0–II, commonly I; dorsal-row tubercles 11–16; ventral-row tubercles 9–13........ Benthophilus baeri

16b. first dorsal-fin spine II–IV, commonly III; dorsal-row tubercles 18–24; ventral-row tubercles 15–20... Benthophilus spinosus

17a. dark blotches on back absent or indistinct............................................ Benthophilus macrocephalus

17b. three distinct blotches along midline of back............................................................... 18

18a. medial groove on head; granules on head large (some of them almost of same size as nearby tubercles); head and dorsal-row tubercles flattened, rounded; spinules small, arranged in numerous radial rows covering entire surface of tubercles......................................................................................... Benthophilus casachicus

18b. no medial groove on head; granules on head tiny; head and dorsal-row tubercles markedly conical, polygonal; spinules small to large, arranged in one or two radial rows located only on posterior surface of tubercles........................... 19

19a. upper jaw projecting beyond lower jaw; small granules on upper eye surface; often two tubercles between eyes; precaudal vertebrae 10–11, commonly 11........................................................ Benthophilus leobergius

19b. upper jaw not projecting beyond lower jaw; no granules on upper eye surface; always one tubercle between eyes; precaudal vertebrae 9–10, commonly 9...................................................... Benthophilus mahmudbejovi

20a. second dorsal fin branched rays 6–11; suborbital longitudinal row a present; anterior oculoscapular canal with paired pore λ present or absent, no pore σ;............................................................................ 21

20b. second dorsal fin branched rays 14–20; suborbital longitudinal row a absent; anterior oculoscapular canal not shortened anteriorly: pore λ single and a paired pore σ in front of it on the snout........................................... 24

21a. transverse postorbital row tra long, extending downwards to or near the suborbital longitudinal row b; interorbital papillae present.............................................................................. Hyrcanogobius bergi

21b. transverse postorbital row tra short, behind pore α, ending downwards far from the suborbital longitudinal row b; interorbital papillae absent, even if anterior oculoscapular canal ends at paired pore κ (in some Knipowitschia caucasica and Knipowitschia iljini ).............................................................................................. 22

22a. anterior oculoscapular canal not uniting in posterior interorbit, pore κ double; canals anterior to pores κ typically absent; preopercular canal commonly absent....................................................... Knipowitschia iljini

22b. anterior oculoscapular canal uniting in posterior interorbit, with one pore κ; canals anterior to pore κ present, extending anteriorly to pores λ (anterior oculoscapular canal reduced with no paired pore λ only very rarely in Knipowitschia caucasica and only from the Aegean Anatolian area of the Mediterranean Sea); preopercular canal present...................... 23

23a. posterior oculoscapular canal present................................................... Knipowitschia caucasica

23b. posterior oculoscapular canal absent................................................ Knipowitschia longecaudata

24a. anterior nostril an elongate tube, extending beyond upper lip; scales of the lateral row 36–48......... Proterorhinus nasalis

24b. anterior nostril tubular but not beyond upper lip; scales of the lateral row 49–85................................... 25

25a. suborbital transverse rows of neuromasts 8–10, typically five rows in front of suborbital longitudinal row b and three below row b; scales small..................................................................... Mesogobius nonultimus

25b. suborbital transverse rows of neuromasts 7 (8 rows in Neogobius bathybius ); four rows (five in Neogobius bathybius ) in front of suborbital longitudinal row b and two transverse rows below row b; scales large................................ 26

26a. head anterior to level of preopercle, at least in dorsal midline and opercle not covered with scales; spots on the body form more or less regular oblique (diagonal) bands (stripes), descending forward........................... Babka gymnotrachelus

26b. head and opercle (at least the upper part) completely covered with scales; spots on the body do not form oblique bands (stripes)............................................................................................ 27

27a. five suborbital transverse (vertical) rows of neuromasts in front of suborbital longitudinal row b; first dorsal fin rays usually VII................................................................................. Neogobius bathybius

27b. four suborbital transverse (vertical) rows of neuromasts in front of suborbital longitudinal row b; first dorsal fin rays usually VI ................................................................................................ 28

28a. posterior nostril markedly distant from the anterior edge of the orbit, by more than half eye diameter..... Neogobius caspius

28b. posterior nostril near the anterior edge of the orbit, the distance less than half eye diameter.......................... 29

29a. first dorsal fin with rear proximal dark spot.............................................. Neogobius melanostomus

29b. first dorsal fin without rear proximal dark spot............................................................. 30

30a. coloration pale, sandy ( Fig. 25 ); nape and predorsal area scaled completely with ctenoid scales........... Neogobius pallasi

30b. coloration not pale and sandy, usually densely dotted or with reticulate pattern with mid-lateral blotches and dorsal saddles ( Figs. 26 , 28–33 ); nape and predorsal area scaled completely with cycloid scales, or anteriorly with cycloid and posteriorly with ctenoid scales....................................................................................... 31

31a. first dorsal fin without anterior oblique dark stripe and light marginal band; inshore brackish water or euryhaline........ 32

31b. first dorsal fin with an anterior oblique dark stripe and light marginal band; freshwater............................. 34

32a. three suborbital transverse rows below suborbital longitudinal row b ................................ Ponticola syrman

32b. two suborbital transverse rows below suborbital longitudinal row b ............................................. 33

33a. anal fin with 11–14 (usually 12) branched rays, head depth at eyes about 0.6 head width, interorbit 0.6–1.1 eye diameter, snout 1.5–2.3 eye diameter, pelvic disc 0.7–0.9 abdomen length........................................ Ponticola gorlap

33b. anal fin with 13–15 (usually 13) branched rays, head depth at eyes slightly less to somewhat greater than width, interorbit 0.4–0.6 eye diameter, snout 0.9–1.2 eye diameter, pelvic disc 0.9 to slightly more than abdomen length.... Ponticola goebeli

34a. second dorsal fin with 17–18 (usually 18) branched rays, predorsal scales 25–26 (usually 26), caudal fin length 21.4–23.1% SL, first dorsal fin base 11.0–11.7% SL, snout to first dorsal fin 36.4–37.7% SL, pelvic fin length 14.0–15.6% SL, eye diameter 18.0–18.4% HL, upper lip length 20.3–21.9% HL; Kura River basin ( Azerbaijan, Georgia, and Turkey)..... Ponticola cyrius

34b. second dorsal fin with 14–17 (usually 15–16) branched rays, predorsal scales 17–25 (usually 19–22), caudal fin length 23.3– 31.4% SL, first dorsal fin base 14.1–18.5 % SL, snout to first dorsal fin 30.5–36.5% SL, pelvic fin length 19.4–26.2% SL, eye diameter 18.8–25.7% HL, upper lip length 27.1–43.4% HL; South Caspian freshwater habitats in Iran................. 35

35a. head, lips, cheeks, predorsal and body coloration reticulate, postorbital profile oblique, cheek prominent; Kaboudval Stream (Golestan Province)................................................................. Ponticola hircaniaensis

35b. head, lips, cheeks, predorsal and body color uniform, body coloration not reticulate, postorbital profile subhorizontal (i.e., less oblique), cheek not prominent; western freshwater habitats of the South Caspian sub-basin (Gilan and western Mazandaran Province)........................................................................................... 36

36a. inhabiting the upper Sefidroud drainage basin................................................. Ponticola iranicus

36b. inhabiting western freshwater habitats of the South Caspian sub-basin in Iran, from Karganroud to Kheiroud except for the upper Sefidroud drainage basin............................................................ Ponticola patimari

Figures

FIGURE 25. Neogobius pallasi. Miankaleh, Mazandaran Province, Iran.

FIGURE 26. Ponticola cyrius. Kura River at Yalnýzçam, northeastern Turkey. Photo by C. Kaya.

FIGURE 28. Ponticola goebelii. ZM-CBSU S014-1, female, 55.4 mm SL, off Anzali, Gilan Province, Iran.

FIGURE 29. Ponticola gorlap. Polroud River, Gilan Province, Iran (Zarei et al. 2022a).

FIGURE 30. Ponticola hircaniaensis. ZM-CBSU S099-5, male, paratype, 73.55 mm SL, Kaboudval Stream, Golestan Province, Iran (Zarei et al. 2022a).

FIGURE 31. Ponticola iranicus. Sefidroud at Imamzadehashem, Gilan Province, Iran.

FIGURE 32. Ponticola patimari. Massuleh River, Gilan Province, Iran (Zarei et al. 2021).

FIGURE 33. Ponticola syrman. ZM-CBSU S065.2-1, 183.2 mm SL, off Neka, Mazandaran Province, Iran (Zarei et al. 2022a).