Pseudogobius melanosticta ( Day, 1876 )

Larson, Helen K. & Hammer, Michael P., 2021, A revision of the gobiid fish genus Pseudogobius (Teleostei, Gobiidae, Tridentigerinae), with description of seven new species from Australia and South-east Asia, Zootaxa 4961 (1), pp. 1-85 : 47-53

Pseudogobius melanosticta ( Day, 1876)

Black-spotted snubnose goby

Figs 1 , 18–19 , Tables 1–5, 15

Gobius melanosticta Day, 1876: 290 , pl. 63, fig. 2 (backwaters of Madras, India).— Whitehead & Talwar 1976: 162 (Madras); Bauchot et al. 1991: 36 (Madras); Ferraris et al. 2000: 299 (Madras).

? Gobius chilkensis Jenkins, 1910: 137 (Lake Chilka, Gopkuda Island).

Vaimosa serangoonensis Herre, 1937 in Herre & Myers 1937: 40, pl. 2 (creek at Serangoon, Singapore).

Vaimosa adyari Herre, 1945: 402 (Adyar River, India).

Stigmatogobius javanicus — Talwar & Jhingran 1991: 947 ( India).

Pseudogobius sp.— Akihito et al. 2000: 1210 ( Japan); Akihito et al. 2013: 1437 ( Japan).

Pseudogobius sp. 1— Zhou & Gao 2011: 294 (Taiwan).

Pseudogobius sp. 2— Zhou & Gao 2011: 293 (Taiwan).

Pseudogobius melanostictus —Larson in Randall & Lim 2000: 640 (South China Sea); Larson 2001: 203 ( India, Singapore, Sri

Lanka, Indonesia, Papua New Guinea); Larson & Murdy 2001: 3601 (western central Pacific); Larson & Lim 2005: 142 (Mandai mangroves, Singapore); Larson et al. 2008: 144 ( Singapore); Tran et al. 2013: 144 (Mekong Delta, Vietnam).

Pseudogobius melanosticta — Kottelat 2013: 422 ( India; Singapore); Hammer et al. 2021: 2 ( Australia, New Guinea and Vietnam [diagnosable at nuclear and mitochondrial markers]).

Pseudogobius gastrospilos — Huang et al. 2014a: 95 ( Taiwan, Thailand, Palau); Chen et al. 2014a: 131 ( Taiwan, Thailand, Palau).

Pseudogobius gastrospilus — Günther 1861: 43 (Sea of Batavia [ Indonesia]).

Material Examined. INDIA: Lectotype of Gobius melanosticta, MNHN A. 18, 32 mm SL male, Madras, F. Day . Paralectotypes of Gobius melanosticta, BMNH 1889.2.1.3388–97, 11(18–33), Madras, F. Day; NMW 84081.1 - 2 , 2 (22.5–36, smaller specimen is an Asterropteryx ), Madras . Holotype of Vaimosa adyari, CAS-SU 39864, 21 mm SL male, Adyar River , Madras, A.W. Herre, 4 January 1941 . SRI LANKA: ZMH 19309, 4 (20–32), lagoon, Panadhure, Duncker, 30 July 1909 . SINGAPORE: Holotype of Vaimosa serangoonensis, CAS-SU 30984, 28.5 mm SL male, Serangoon, A.W. Herre, 18 March 1934 . SMF 18199, 1 (40), H. Berkenkamp, July 1983 . JAPAN: NTM S.12136- 003, 13(9–25), Sumiyoshi Village, Iriomote Island , HL 85-55, H.K. Larson and H. Senou, 19 August 1985 ; PHIL- IPPINES: USNM 268186 , 11 (27–32.5), Siquijor Island , Negros Oriental, L. Knapp and party, 14 May 1979 . FED- ERATED STATES OF MICRONESIA: NTM S.16184-002, 3(25–27.5), Lulu River , Yap, B. Tibbatts and party, 27 September 2005 . INDONESIA: USNM 405342 , 17 (20–27), tambak [pond] at Sungei Wantgu, Kendari , Sulawesi Tenggara, L. Parenti, D. Lumbantobing and S. Sauri, 15 June 2010 ; WAM P.35062.001, 11(19–25), brackish lake on Mauwara Island, Triton Bay , West Papua, 2–3 m depth, G . R. Allen , 30 April 2007 ; CMK 6286, 3(31.5–35.5), Pangandaran , Java, Vivaria Indonesia, 8 July 1988 ; CMK 4546, 7(14–31), Bungus Bay , Sumatra, P. Bianco and M. Kottelat, 29 November 1984 . PAPUA NEW GUINEA: USNM 316051 , 2 (27–35), stream behind Trobriand Hotel, Kiriwinna, Trobriand Islands , B. Collette, 6 June 1970 ; USNM 316200 , 10 (21.5–33.5), brackish water lagoon, Puk Puk Island , Bougainville, 9 March 1965 . NEW CALEDONIA: MNHN 2000-5232 , 2 (33–33.5), Nera, Marquet, 4 June 1995 . AUSTRALIA: NTM S.17698-002, 7(19.5–34.5), Palm Cove creek just before estuary, north of Cairns , G. Moore and M. Hammer, 2014 ; NTM S.17710-001, 1(27.5), tissue A 02738, Palm Cove creek, north of Cairns , G. Moore, 2014 .

Additional material (no data taken). INDIA: FMNH 100604 , 1 , Madras; CAS-SU 37179 , 14 , South Corbyns Cove, Port Blair , South Andamans ; CAS-SU 19342 , 27 , Cochin, Cheranellore . VIETNAM: NTM S.17895-001, 1, Bac Lieu, K. Shibukawa and party, 19 May 2012 . SRI LANKA: USNM 316198 , 3 , Ceylon estuaries, C.C. Koenig, 9 April 1970 . INDONESIA: CMK 8965, 1, Singaraja, Bali; CMK 8956, 1, Bali; CMK 8903, 1, Bali; CMK 8902, 1, Seseh, Bali; NTM S.14147-008, 26, Sejorang River , South Sumbawa, AQ 20, K. Martin, 28 March 1995 . PHILIP- PINES: CAS-SU 69917 , 6 , Coron, Busuanga, A.W. Herre, 22 June 1940 . PALAU: CAS-SU 76089 , 5 , bomb crater, Koror Island, Fehlmann and party, 1 October 1955 . MALAYSIA: ZRC 22719–54 , 36 , Trengganu . PAPUA NEW GUINEA: USNM 316202 , 1 , Mangrove creek, Oro Bay, Popondetta District , T. Roberts, 4 August 1975 ; ZMH 19312, 3 , Simpsonhafen, Blanche Bay , Gazelle Peninsula, Duncker, 5 August 1908 ; NTM S.16645-002, 30, Ularimbin Creek, Wewak, J. Armbruster , R. Betancur, P. Unmack and A. Ko’ou, 1 October 2007 . VANUATU: USNM 357807 , 12 , lakes on Shepherd Islands, J. T. Williams and party, 19 June 1996 . SINGAPORE: CMK 7427, 2; SMF 18199, 1 , Singapore region , H. Berkenkamp, July 1983 . SRI LANKA: CMK 7049, 1, Negombo Lagoon. AUSTRA- LIA: NTM S.17710-001, 1, Palm Cove; NTM S.17696-002, 6, Holloways Lake , Cairns, G. Moore and M. Hammer, 28 January 2014 ; AMS I.21259-003, 15, creek at Cape Tribulation, D. Hoese, 11 August 1979 .

Diagnosis. A large Pseudogobius with second dorsal rays I,6–8; anal rays I,7–8; pectoral rays 14–16; 15–16 segmented caudal rays, usually in 9/7 pattern; lateral scales 23–26; TRB 8–10; predorsal scales 6–8; predorsal scales ctenoid at sides and/or posteriorly; opercle with 2–4 rows of ctenoid scales, rarely with cycloid scales (if so then predorsal scales ctenoid); cheek naked; shoulder girdle smooth or with narrow flange, which may be angled outward (several specimens with 1–3 small flat knobs or flanges); tongue short, tip blunt to slightly concave; upper jaw teeth in 2–6 rows, in males, teeth in outer row always largest, slightly curved, conical to slightly flattened, outer row of upper jaw teeth in females variable, may be similar to males with two rows of upright slightly flattened teeth, or row of short compressed blunt to pointed teeth; scale margins edged with brown, giving diffuse network appearance, distinctive wide dark brown to black oblique bar running from lower rear edge of eye to above lower margin of preopercle; first dorsal fin pointed, with two broad blackish stripes; widespread, known from estuarine to fresh waters across the Indo-west Pacific.

Description. Based on 38 specimens, 20–40 mm SL. An asterisk indicates the counts of the 31 mm SL lectotype ( Fig. 19D ).

First dorsal VI*; second dorsal I,6–8 (usually I,7*); anal I,7–8 (usually 7*); pectoral rays 14–16* (usually 15); segmented caudal rays 8/7–9/7, nearly always 9/7; branched caudal rays 6/7–8/7, modally 8/7; lateral scale count 23–26 (usually 25, 24 in lectotype); TRB 7½ –9½ (usually 8*); predorsal scale count 6–8 (usually 7*). Gill rakers on outer face of first arch 3+6 (1), 3+7 (in 1), 3+9 (2).

Head and anterior half of body rounded to compressed; posterior half of body compressed. Head wider than deep, adult males without inflated cheeks, HL 24.4–28.3% SL (mean 26.6%). Depth at posterior preopercular margin 60.0–77.0 HL (mean 67.7%). Width at posterior preopercular margin 56.3–82.4% HL (mean 71.7%). Mouth small, subterminal, very slightly oblique, upper jaw very slightly in advance of lower; jaws reaching to anterior edge of eye in females and to mid-eye in adult males; upper jaw 29.1–45.4% HL (mean 36.0%); symphysis of lower jaw may be raised; lips thin, lower lip broadly fused to chin anteriorly. Eyes lateral, high on head, top forming part of dorsal profile, 26.3–36.0% HL (mean 31.2%). Snout bluntly rounded to steep and bluntly pointed, 21.6–29.6% HL (mean 25.6%). Interorbital moderate, 12.6–23.1% HL (mean 16.7%). Body depth at anal origin 19.6–25.8% SL (mean 22.8%). Caudal peduncle compressed, length 25.0–32.0% SL (mean 29.1%). Caudal peduncle depth 13.0–29.6% SL (mean 21.0%).

First dorsal fin tall, triangular and pointed, first to third spines long, usually second spine longest; in males, first three spines may be elongate, reaching well back to front part of second dorsal fin when depressed (may reach sixth fin element); fin falling short of second dorsal in females and first spine never longest; fin length 17.7–33.8% SL (mean 23.1%). Second dorsal spine length 14.8–27.5% SL (mean 18.8%). Third dorsal spine length 13.8–25.3% SL (mean 18.4%). Second dorsal fin taller than first but falling well short of caudal fin base when depressed, fin slightly pointed posteriorly. Anal fin of similar height to second dorsal but more rounded posteriorly; rays falling short of caudal fin base when depressed. Pectoral fin oval, central rays longest, extending back to vertical above anal fin origin, 22.6–29.4 % SL (mean 25.2%). Pelvic fins oval, reaching to anus or nearly so in males; just falling short in females, 15.8–25.5% SL (mean 22.6%). Caudal fin large, rounded to slightly pointed posteriorly, 28.1–40.6% SL (mean 33.0%).

Anterior nostril in short tube, oriented down over upper lip. Posterior nostril oval, with very low rim, placed at oblique angle at mid-level of eye. Gill opening extending forward to under opercle or forward just past pectoral fin base. Gill rakers on outer face of first arch very short pointed stubs. Shoulder girdle smooth or with narrow smooth to irregular flange, which may be angled outward; several specimens with 1–3 small triangular flat knobs or flanges present. Tongue short, tip blunt to slightly concave. Upper jaw teeth in 3–6 rows, narrowing to fewer at sides; in males, teeth in outer row always largest, slightly curved, conical to slightly flattened, teeth in inner rows small, close-set, sharply pointed; upper jaw teeth in females variable, may be similar to males with two rows of upright slightly flattened teeth, or with outer row of short compressed blunt to pointed teeth and a band of tiny close-set sharp teeth behind. Lower jaw teeth in males in 2–3 rows, teeth small, close-set and pointed, may be 2–3 larger curved caniniform teeth behind rows at jaw symphysis; in females, lower jaw teeth in 2–3 rows, small, conical, close-set, with sharp tips.

Body scales ctenoid, extending forward onto predorsal at least to above opercle, all predorsal scales may be ctenoid, predorsal may have ctenoid scales posteriorly and cycloid anteriorly, or with mid-line of nape with cycloid scales and sides ctenoid (variation occasionally observed within specimen lots from same locality), cycloid scales on breast and pectoral fin base; opercle with 2–4 rows of scales, usually ctenoid, especially upper row, six out of 32 specimens with all cycloid scales on opercle (and these always with ctenoid nape scales); belly scales cycloid, often with ctenoid scales close to pelvic fins. Lateral canals, pores and sensory papillae pattern as in Fig. 18 .

Coloration of preserved material. Head and body yellowish white to light brown, with scale margins on upper half of body (at least) thinly edged with dark brown to black, giving diffuse network appearance ( Fig. 19 ). Head brown dorsally, nape scales with darker brown to almost blackish spots and blotches which may form a reticulate pattern. Snout and interorbital covered with small dark brown spots and short vermiculate lines, which may coalesce into irregular blotches. Side of head brown to light brown, paling ventrally, underside of head dark in males; chin with scattered dark spots in both sexes (darkest in males). Distinctive wide dark brown to black oblique bar from lower rear edge of eye, running down to end above lower margin of preopercle just before angle of bone; second dark brown bar (may be indistinguishable from dark pigment on snout) running from front of eye through anterior nostril and ending on upper lip. Lips dark brown to blackish, margin of lower lip usually much darker than upper and contrasting with pale to brown-spotted chin. Side of body covered with dark brown spots and small blotches, interspersed with dark scale margins; small blotches may be larger along mid-line of body and may form 1–2 broken dark lines. Mid-base of caudal fin with three small blackish to black elongate spots forming a horizontal Y. Breast brown to dark brown in males, pale in females. Belly usually pale in both sexes but may be greyish in heavily pigmented males; upper half of peritoneum black, sides abruptly pale. Pectoral fin base brown with diffuse dark brown blotch or horizontal bar dorsally.

First dorsal fin transparent with two broad pale grey to black stripes, one along middle of fin and one (broader) distally, both stripes darkening posteriorly; may be additional dark blotches along base of fin; in adult males the elongate fin spines are blackish and membranes pale grey. Second dorsal fin transparent to greyish, with about three grey to blackish stripes or rows of spots along its length. Anal fin transparent to plain grey to blackish; some darker spotting at base posteriorly. Caudal fin transparent to pale grey with 4–7 irregular oblique rows of blackish spots and streaks, most distinct on upper two-thirds of fin; horizontal Y-mark on fin base joining anteriormost row of spots. Pectoral fin translucent to dark grey, rays darker than membrane; bases of rays on upper part of fin darkest. Pelvic fins translucent to almost blackish (in large males).

The lectotype (MNHN A.18), despite being over 100 years old, still retains the dark spots scattered over the body and nape, as well as the dark brown oblique cheek bar and dark streaks on the first dorsal fin ( Fig. 19D ).

Coloration of fresh material. Based on photos of live fish by Gerry Allen, Renny Hadiaty, Christophe Maillet, Gerhard Ott and from Fig.19 ; also from colour photos of captive adults in Zhou & Gao (2011), as Pseudogobius sp. 1 and 2 (female and male).

Head and body greyish yellow, pale yellowish white or whitish grey (apparently depending upon substrate colour), with dull yellow, orange-yellow, light brown to blackish small spots and blotches scattered along scale rows on side and more irregularly on head. In some specimens, a diffuse mid-lateral band of blackish spots or series of 4–5 blackish blotches overlie the orange-yellow or brown spots on body. Five internal blackish blocks of pigment at mid-ventral line of caudal peduncle may be visible from origin of anal fin to just before caudal fin base; blocks low, not reaching to mid-line of body. Peritoneum may show through body wall as silvery white on sides. Opercle iridescent pearly blue or greenish. Cheek may have scattered yellowish gold pigment around the black “tear” mark running down from eye. Iris red-gold.

First dorsal translucent to yellow, crossed by two black bands, tip of fin may be grey or black; small bright blue blotch may be present at rear of fin. Second dorsal fin transparent with diffuse grey speckles and crossed by two diffuse grey stripes.Anal fin translucent whitish to blue, margin usually bright white to blue. Caudal fin translucent pale grey with 7–9 irregular fine dusky grey bands. Pectoral fin transparent. Pelvic fins translucent white to pale greyish.

Comparisons. This is a distinctive species that is not likely to be confused with others, due to its diagnostic first dorsal fin colour pattern (especially when live or freshly preserved), with elongate fin spines in males, its usually steep rounded snout, generally spotted body colour pattern and distinct black “tear” bar from eye crossing cheek.

Distribution. This is the most widespread species of Pseudogobius , distributed across the Indo-west Pacific. Specimens are known from Andaman Islands, India, Sri Lanka, Japan, Indonesia, Malaysia, Singapore, Brunei, Philippines, Palau, New Guinea, northern Australia, Solomon Islands, Vanuatu and New Caledonia. The Australian specimens from the Cairns area (Wet Tropics Bioregion, north-eastern Queensland) are a new record for the country.

Ecology. Shallow estuarine to freshwater, found in estuaries of rivers, streams and mangroves. The Palm Cove (Queensland) specimens came from a flowing freshwater creek with pebble and cobble substrate.

Remarks. Huang et al. (2014a) placed Gobius melanosticta Day as a junior synonym of P. gastrospilos (Bleek- er, 1853) without giving any reason. They apparently did not examine any type material of P. melanosticta and did not note whether the scales on the nape and opercle in their material were ctenoid or cycloid. Their photographs show specimens of P. melanosticta while the accompanying description provides minimal information. Bleeker’s type specimen of Gobius gastrospilos is a Pseudogobius . Huang et al.’ s (2014a: 95, fig. 1a) figure of the holotype of Gobius gastrospilos ( Fig. 25D ), shows two large dark spots at the base of the caudal fin, with the size and spacing of these spots unlike those in P. melanosticta (see Huang et al. 2014a: 95, fig. 1b,c). Therefore, Bleeker’s type specimen is not the same as P. melanosticta and is here placed in P. poicilosoma (which see) based on counts and distribution.

There are a number of other syntypes of Day’s Gobius melanosticta ; see Whitehead and Talwar (1976): BMNH 1889.2.1.3388–3397 (11); AMS B.8202 (1); MNHN A.18, (1); MZUF 4704 (1); RMNH 1886 (1); ZSI 187 (1, figured specimen, lost); ZSI 291–220 (2, lost), with possible syntypes in NMW 84081.1, (1) and NMW 84081.2, (1). Of the 11 specimens in BMNH 1889.2.1.3389–97, 9(28–33) are Pseudogobius , 1(30) is a Drombus , and 1(18) is possibly a Palutrus . Of the possible NMW syntypes of Gobius melanosticta, NMW 84081.2 is an Asterropteryx while NMW 84081.1 is Pseudogobius melanosticta .

Due to the confusion over the status of this species (and its syntypes), we herein designate Day’s syntype specimen MNHN A.18, a 31 mm SL female, as the lectotype of Gobius melanosticta Day. It is in reasonable condition (despite having a tag tied around its middle) and shares features with other type and non-type specimens of Pseudogobius melanosticta .

We place Gobius chilkensis Jenkins, 1910 , here with some uncertainty, as his illustration resembles P. melanosticta . The location and condition of the types could not be confirmed.

Figures

FIGURE 1A. Distribution maps of species in the genus Pseudogobius, based upon material examined and inspected (circles) with the type localities indicated (squares).

FIGURE 18. Sketch (incomplete) of sensory papillae and pores of holotype of Vaimosa serangoonensis (= Pseudogobius melanosticta), 28.5 mm SL male, CAS-SU 30984, Serangoon, Singapore. Drawing by HKL.

FIGURE 19. Pseudogobius melanosticta, Indo-west Pacific, (A) captive male, creek at Palm Cove, Cairns; (B) captive female, creek at Palm Cove, Cairns, photos by MPH; (C) fresh male (top) and female from Mekong Delta, Vietnam, photos by K. Shibukawa (courtesy FIMSEA Working Group); (D) preserved lectotype of Gobius melanosticta, 32 mm SL male, MNHN A.18, Madras, India, photo by MPH.

FIGURE 25. Pseudogobius poicilosoma, East Asia, South Asia and South-east Asia, (A) wild male (right side reversed), Hong Kong, photo by copyright H.T. Cheng; (B) fresh male (top) and female from Mekong Delta, Vietnam, photos by K. Shibukawa (courtesy FIMSEA Working Group); (C) well preserved topotypic specimen, 27.5 mm SL male, CMK 6083, south of Tanjung Pasir, Java, Indonesia, photo by MPH; (D) holotype of Gobius gastrospilos, RMNH 4676, 30 mm SL male, Batavia [Jakarta], Java, photo by S.-P. Huang.