Pseudogobius hoesei, Larson & Hammer, 2021

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 : 34-39

Pseudogobius hoesei n. sp.

Bandtail snubnose goby

urn:lsid:zoobank.org:act:0780BBE4-FE3B-47A7-9CB9-54DDD3F89D0B

Figs 1 , 12–13 , Tables 2–5, 12

Pseudogobius poicilosomus —Larson 2001: 203 (in part; Indonesia; Papua New Guinea; Northern Territory, Queensland); Kottelat 2013: 422 (in part; Indonesia).

Pseudogobius sp. D ‘striped’— Hammer et al. 2021: 5 (northern Australia, Gulf of Carpentaria, western Cape York, Torres Strait, and southern New Guinea [diagnosable at nuclear and mitochondrial markers]).

Material Examined. Holotype: QM I.40993 (ex AMS I.23287-009), 27 mm SL male, Bellvue Creek , Embley River, Weipa, Queensland, Australia, D. Hoese and D. Rennis, 13 October 1982 . Paratypes: AUSTRALIA: AMS I.23287-009, 145(8–28), same data as holotype ; QM I.38168, 1(31), Vigden Creek, Horn Island , Torres Strait, Queensland, G. Hinchcock, 12 August 2007 ; QM I.38170, 3(25–29), Vigden Creek, Horn Island , Torres Strait, Queensland, G. Hinchcock, 5 August 2007 ; CSIRO B.2513, 4(15–25), Prince of Wales Island , Torres Strait, Queensland, J.S. Hynd, 5 September 1959 ; QM I.38175, 4(25–28.5), Saibai Island , pond SW of S end of airstrip, G. Hitchcock, Queensland, 25 October 2007 ; QM I.38182, 12(19–34.5), Boigu Island , lagoon at S side of airstrip, Queensland, G. Hitchcock, 5 November 2007 ; NTM S.16869-001, 6(26–30), main channel, McArthur River , Northern Territory, D. Thorburn, 6 May 2008 . INDONESIA: MZB 23679, 6 (20.5–30), Bemun mangrove channel, Sungai Mermar, Pulau Barakan, Aru Islands , Site 16 , R. Hadiaty, G. Allen, M. Erdmann and S. Sauri, 6 December 2016 ; MZB 21738, 1 (24.5), Sungai Kofukim, Anak Sungai Batu Putih, Ds. Kolaha, Distr. Sisir, Pulau Kola, Aru Islands , Maluku , R. Hadiaty, G. Allen and M. Erdmann, 7 December 2013 ; WAM P.31299- 004, 8(21.5–33), 30 km south on Portsite Road, Timika, Papua, G . R. Allen, 20 April 1997 ; WAM P.31255-005, 1(33.5), mangrove creek on Portsite Road, about 100 m S of Kilometre 7, G . R. Allen and party, 21 January 1997 ; NTM S.15100-001, 1(36), Ajkwa River , Papua, Freeport Mine survey, 7 February 2000 ; NTM S.18264-001, 1(28.5), Lower Mawati River , Papua, K. Hortle, 1997 ; NTM S.15117-001, 9(21–33), Lower Mawati River , Freeport Mining, 28 February 1997 ; NTM S.15193-001, 14(18–33.5), Lower Mawati River , Freeport Mine survey, 4 March 1998 ; NTM S.15099-002, 2(30–33.5), Ajkwa River , Papua, Freeport Mine survey, 6 December 1997 . PAPUA NEW GUINEA: AUM 47615, 26 (12.5–27), Bautama Creek , at upper limit of mangroves off Magi Highway, Port Moresby, P. Unmack and T. Mala, 19 October 2007 ; NTM S.16646-007, 10(22–31.5), Bautama Creek , at upper limit of mangroves off Magi Highway, Port Moresby, P. Unmack and T. Mala, 19 October 2007 ; BPBM 15836 , 2 (32.5–33), Meiro River , Madang, J.E. Randall and party, 15 August 1973 ; NTM S.13672-004, 1(29), Biges River , Sek Harbour, Alexishafen, H.K. Larson and party, 12 October 1992 ; NTM S.13674-011, 2(32.5–34), Biges River , Alexishafen, H.K. Larson and party, 12 October 1992 ; USNM 316208 , 3 (30.5–33), Dogura Creek , 10 miles SE of Port Moresby on Rigo Road, B.B. Collette, 21 June 1970 .

Additional material (no data taken). INDONESIA: NTM S.14829-001, 9, Lower Mawati River , Papua, Freeport Mining, 8 December 1997 ; TUBRI 172779 , 4 , Lower Mawati River , Papua, D. Norris, 4 September 1993 ; TUBRI 172862 , 1 , Lower Mawati River , Papua, D. Norris, 27 January 1994 ; TUBRI 172843 , 2 , West Minajerwi River , Papua, D. Norris, 26 January 1994 ; TUBRI 172827 , 1 , East Ajkwa River , Papua, D. Norris, 26 January 1994 . PAPUA NEW GUINEA: USNM 297095 , 5 , Cape Ward Hunt, B. Collette, 17 June 1979 ; NTM S.13689-013, 20(14-35), Biges River, Mililat Harbour , Madang, HL 92-64, H.K. Larson and party, 23 October 1992 ; WAM P.26751-007, 2, Binaturi River , Ture Ture, G. Allen, 27 September 1979 . AUSTRALIA: NTM S.12776-001, 2, Heales Creek , Weipa, Queensland, S. Blaber, 27 August 1987 ; AMS I.23281-024, 16, Mission River Mouth, Weipa , Queensland, D.F. Hoese and D. Rennis, 11 October 1982 ; NTM S.12775-007, 4, Embley River, Weipa , Queensland, S. Blaber, 24 August 1987 ; NTM S.18266-01, 20, Trunding Creek, Weipa , Queensland, M. Hammer and party, 22 November 2015 ; NTM S.16506-001, 2, Albert River , Queensland, NIC 3 , NAFF, 12 May 2007 ; NTM S.16538-001, 2, Little Bynoe River , Queensland, P. Unmack , PU01-40 , 10 August 2001 ; NTM S.12419-004, 81, Cox River , Northern Territory, H. Larson and W. Houston, 18 July 1988 ; USNM 316209 , 1 , Little Lagoon tributary, Groote Eylandt, Northern Territory , R. Miller and party, 26 June 1948 .

Diagnosis. A moderate-sized Pseudogobius with second dorsal rays I,6–7; anal rays I,6–7; pectoral rays 14–17; 16 segmented caudal rays in 9/7 pattern; lateral scales 23–27; TRB 7–8; predorsal scales 6–7; opercle with several rows of cycloid scales, cheek naked; shoulder girdle with smooth to fleshy edge; tongue reduced, tip blunt; in males, outer row teeth evenly spaced, compressed, with bluntly pointed tips while in females, outer row teeth compressed, blunt-tipped and closely-set; scale margins on head and body edged with brown, giving body net-like pattern, 5–6 distinct dark brown or black elongate blotches along mid-side of body, posteriormost at hypural crease where it extends onto caudal fin and coalesces with broad vertical dark brown bar on fin base; known from mangrove creeks and lower reaches of streams on the Australian plate (Aru Islands, New Guinea and north-eastern Australia).

Description. Based on 55 specimens, 23.0–27.0 mm SL. An asterisk indicates counts of the holotype ( Fig. 13D ).

First dorsal VI*; second dorsal I,6–7 (usually I,7*); anal I,6–7 (usually I,7*); pectoral rays 15–17 (usually 16*); segmented caudal rays 16*, in 9/7 pattern; branched caudal rays 7/6–8/7, usually 8/7*; lateral scale count 23–27 (24 in holotype); TRB 7–8* (usually 8); predorsal scale count 6–7 (usually 7*).

Body rounded or slightly compressed anteriorly, compressed posteriorly. Head slightly wider than deep, HL 23.1–29.1% SL (mean 26.3%). Head depth at posterior preopercular margin 55.7–98.5% HL (mean 66.3%). Head width at posterior preopercular margin 61.8–85.2% HL (mean 71.6%). Mouth small, subterminal, slightly oblique; jaws reaching to vertical through anterior half of eye; males with slightly longer jaws; upper jaw 28.6– 51.1% HL (mean 39.3%); lips thin, lower lip broadly fused to chin anteriorly. Eyes lateral, high on head, top may form part of dorsal profile, eye width 25.0–35.3% HL (mean 30.9%). Snout rounded, 22.6–26.8% HL (mean 26.3%). Interorbital narrow, 13.7–29.3% HL (mean 18.6%). Body depth before anal origin 19.3–22.9% SL (mean 20.8%). Caudal peduncle compressed, length 26.3–33.3% SL (mean 30.5%). Caudal peduncle depth 11.6–16.1% SL (mean 14.0%).

First dorsal fin low, triangular, third spines longest in females and first spine longest in males. Appressed first dorsal fin falling well short of second dorsal fin origin in both sexes, fin length 16.9–23.1% SL (mean 20.1%). Third dorsal spine length in males 13.3–20.4% SL (mean 16.6%). Third dorsal spine length in females 12.5– 16.4% SL (mean 14.7%). Second dorsal and anal fin heights low, fins rounded posteriorly with first few rays longest, rays falling well short of caudal fin base when appressed. Pectoral fin oval, central rays longest, extending back to vertical just short of anus, 18.6–25.5% SL (mean 22.3%). Pelvic fins oval, short, reaching well short of anus, 16.0–24.0% SL (mean 20.3%). Caudal fin oval, rounded posteriorly, 25.0–35.8% SL (mean 30.8%).

Anterior nostril in short tube, oriented down over upper lip. Posterior nostril oval, with very low rim, placed just below mid-level of eye. Gill opening relatively narrow, extending to just under opercle. Shoulder girdle with smooth to fleshy edge; one specimen with two low fleshy bumps on edge. Tongue reduced, tip blunt. Upper jaw teeth in two rows, in males, outer row teeth evenly spaced, compressed, with bluntly pointed tips; in females, outer row teeth compressed, blunt-tipped and closely-set; teeth in inner row always very small and pointed, mostly concealed in flesh of jaw. Lower jaw teeth in 2–3 rows; in males, outer row teeth small, evenly spaced, compresses with bluntly pointed tips; two small curved symphyseal canines behind anterior tooth row; females with compressed evenly sized blunt teeth in outer row; teeth in inner row the same as in upper jaw, mostly concealed by flesh.

Body scales ctenoid to above pectoral fin base, cycloid scales on predorsal, breast and pectoral fin base; opercle with several rows of cycloid scales; belly scales cycloid. Lateral canals, pores and sensory papillae pattern as in Fig. 12 .

Coloration of preserved material. Head and body whitish, shading to brown on dorsal half, scale margins on head and body edged with brown so that most scales outlined in net-like pattern, 5–6 distinct dark brown or black elongate blotches along mid-side of body, posteriormost at hypural crease where it extends onto caudal fin and coalesces with broad vertical dark brown bar on fin base; small brown spots on predorsal area ( Fig. 13 ). Small dark brown blotches or rounded spots along dorsum, becoming more distinct over caudal peduncle. Ante- rior part of nape, interorbital and snout plain brown, with dark brown bar from eye to middle of lip running just below nostrils and a diffuse pale brownish area on either side of dark brown bar. Cheek may be plain greyish or with two indistinct broad brown bars crossing obliquely. Lips with black to dark brown edges contrasting with white inner skin. Chin and anterior part of isthmus white speckled with melanophores in males, chin lightly speckled in females with isthmus white; remainder of head and breast white; belly white. Thin blackish to dense black mid-ventral line running from middle (or insertion) of anal fin to end at first ventral procurrent ray. Reticulate net-like pattern most pronounced in mature males, with blotches and lines on body, and spots at caudal fin base, becoming obscured and indistinct with the rows of spots or lines on the caudal fin indistinct or intensified. Regional variation in body patterns occurs (excluding mature males, patterned as above), with fish from the Gulf of Carpentaria having more diffuse markings, and fish from the Timika region of New Guinea having a series of distinct horizontal dash like markings along the sides (evident in preserved and fresh specimens).

First dorsal fin translucent to greyish with two diffuse grey to blackish bands; first spine dark grey to black. Second dorsal fin transparent with brownish fin rays and narrow grey margin; largest female specimen with rows of indistinct brownish spots. Anal fin transparent with scattered brownish speckles along rays. Caudal fin transparent with 5–6 rows of dark grey to blackish spots forming distinct lines; caudal base with blackish spot at base of upper procurrent rays and two similar spots on either side of mid-base of fin; spots may be fused into vertical bar or partly separate (lowermost spot usually separated). Pectoral fin with transparent membranes, rays speckled with brown. Pelvic fins whitish with scattered fin brownish speckles. Juveniles (up to 20 mm SL) may have bands in first dorsal fin intensified to blackish, especially the band crossing the middle of the fin.

Coloration of fresh material. From photographs of Indonesian (Aru Islands and Timika region) captive fish by Gerry Allen and Australian fish by Doug Hoese and Fig. 13 . Head and body translucent pale grey, becoming whitish grey or white ventrally, with scale margins thinly edged with dark grey and 4–5 elongate large black blotches along mid-side of body (blotches usually irregular in shape and may fuse). Posteriormost blotch on body ending at hypural crease and coalescing with two black spots on each side of mid-base of caudal fin. Elongate large dark diffuse or dense black blotch above pectoral fin base, extending partly above opercle. Narrow line of variably sized small blackish spots running just below mid-lateral series of blotches; line of spots may be indistinct. Dorsum with 6–7 blackish blotches or short oblique bars, in no particular pattern. Four internal diffuse blackish short bars along mid-ventral line starting at mid-base of anal fin. Snout and predorsal pale grey to brownish grey. Snout with two short dark brown to blackish bars, one before and one after nostril area, which is pale. Cheek pale grey with broad blackish bar from below eye ending mid-cheek or to ventral margin of preopercle; may be second short blackish bar from behind eye diagonally back toward upper part of preopercular margin. Opercle mostly blackish with scattered pale blue or greenish iridophores; pale blue markings may extend anteriorly onto cheek. Iris golden brown. Lips white, edged with black. First dorsal fin transparent with 1–2 broad diffuse grey bands; may be submarginal diffuse red-brown band present. Second dorsal fin transparent with 2–4 rows of blackish speckling, most prominent on fin rays. Anal fin transparent or translucent greyish; may have whitish or bluish white margin. Caudal fin translucent with about six rows of dark grey spots (on fin rays); spots becoming more diffuse posteriorly; two black spots on each side of fin mid-base coalescing with posteriormost blotch on body; and small black blotch across bases of upper procurrent rays. Pectoral fins transparent; rays may be whitish ventrally. Pelvic fins white, dark grey near bases of rays.

Comparisons. This species has been confused with P. aquilonius . The two species can be separated in that P. hoesei has a translucent caudal fin with 5–6 rows of small dark spots (versus caudal fin translucent, plain, with one brown bar at base in P. aquilonius ); about 5–6 elongate blackish blotches along mid-side of body (versus about 5–6 X-shaped or elongate small brown blotches along mid-side of body); and first dorsal fin with two indistinct diffuse grey to blackish bands along fin (versus first dorsal fin translucent with broad diffuse brown band across most of fin).

Distribution. The species appears to be endemic to the Australia and New Guinea region (Sahul Shelf) east of Lydekker’s Line; known from Indonesia (Aru Islands and southern New Guinea), northern and southern Papua New Guinea and Australia (Torres Strait, Cape York and Gulf of Carpentaria).

Ecology. Shallow-water estuarine to lower freshwater, from mangrove creeks and streams under tidal influence. Co-occurs with several local endemic Pseudogobius although can extend further into lower freshwater streams than other species, allopatric with P. jeffi n. sp.

Etymology. Named for our goby-friend and colleague Doug Hoese, in recognition of his years of collection and photography of many poorly known gobies (and because he took a wonderful photo of the holotype).

Remarks. Originally we had considered that Pseudogobius poicilosoma and this species were the same, but as work proceeded we realised that based on biogeography linked to plate tectonics and historical isolation of the Sunda/Wallacea (western Indonesia) and Sahul ( Australia and New Guinea) regions (Lydekker’s Line: Lohman et al. 2011), examination of type specimens, their colour patterns and Bleeker’s descriptions, P. poicilosoma is what has been called P. javanicus (see Remarks for P. poicilosoma ).

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 12. Pseudogobius hoesei n. sp., sensory papillae and lateral canal pores, 34 mm SL female, WAM P.31299-004, Timika, Papua, Indonesia (note that cheek scale behind eye often absent). Drawing by HKL.

FIGURE 13. Pseudogobius hoesei n. sp., New Guinea and north-eastern Australia (A) captive male, Aru Islands, Indonesia, photo by G. Allen; (B) captive female, Aru Islands, Indonesia, photo by G. Allen; (C) fresh male (top) and female, NTM S.18266-01, Weipa, Queensland, Australia, photos by MPH; (D) preserved 27 mm SL holotype male, QM I.40993, Bellvue Creek, Weipa, Queensland, Australia, photo by D. Hoese.