Glossogobius bellendenensis, Hoese, Douglass F. & Allen, Gerald R., 2009

Hoese, Douglass F. & Allen, Gerald R., 2009, Description of three new species of Glossogobius from Australia and New Guinea, Zootaxa 1981, pp. 1-14 : 7-11

Glossogobius bellendenensis , sp. nov.

( Figs. 5–8a , Tables 1–3 )

Glossogobius sp. 4. — Allen et al., 2002: 272.

Holotype. AMS I.22715–004, 43 mm SL male, Eubenagee Swamp, near Innisfail, 17°24'S, 145°58'E, 1 October, 1981, D. Hoese & R. Winterbottom.

Paratypes (all from Russell and Mulgrave Rivers, Queensland). AMS I.21266–001, 3(34–46), 17°14' S, 145°46'E, 16 September, 1979, D. Hoese, Mulgrave River; AMS I.22061–001, 7(27–40), 17°10'S, 145°50'E, 20 September, 1980, D. Hoese & H. Larson, Mulgrave River; AMS I.22063–001, 7(26–39), 17°10'S, 145°50'E, 20 September, 1980, D. Hoese & H. Larson, Mulgrave River; AMS I.22066–001, 6(25–27), 17°10'S, 145°50'E, 20 September, 1980, D. Hoese & H. Larson, Mulgrave River; AMS I.22068–001, 6(28–56), 17°10'S, 145°48'E, 20 September, 1980, D. Hoese, Mulgrave River; AMS I.22712–001, 2(34–35), Goldsborough Forest, Mulgrave River, 17°07'S, 145°47' E; 30 September, 1981, D. Hoese; AMS I.22715–002, 7(33–39), taken with holotype; QM I.20150, 1(47), Creek 2 km south of Russell River Mouth, November, 1982, R.J. McKay & J. Johnson; QM I.29397, 8(40–61), Behana Creek, tributary of Mulgrave River, 17°09'S, 145°49'E, 13 July 1994, P. Graham; QM I.29410, 2(34–37), Behana Creek, tributary of Russell River, 17°08'S, 145°50'E, 16 August, 1994, P. Graham; QM I.29723, 2(32–40), Kearneys Creek, tributary of Mulgrave River, 17°14'S, 145°46'E, 4 December, 1994, K. McDonald; QM I.29998, 4(36–45), Russell River, 17°28'S, 145°52'E, 25 August, 1994, P. Hales; QM I.30917, 1(53), Josephine Creek, on Josephine Falls Road, 17°25'S, 145°54'E, 12 June, 1997, J. Short; QM I.34747, 1(52), Russell River, 17°28'S, 145°52'E, 1 December, 1993, Queensland Fisheries Service; QM I.34754, 2(31–38), Dinner Creek, tributary of Russell River, 17°25'S, 145°60 22, February 1994, Queensland Fisheries Service; WAM P.26970–001, 2(39–42), 8 kms east of Mt. Bellenden Ker, 17°17'S, 145°47'E, 20 September, 1980, D. Hoese, Mulgrave River.

Non-type material: QUEENSLAND: AMS I.22061–002, 4(29–33), cleared and stained, 17°10'S, 145°50'E, Mulgrave River; QM I.20754, 3(22–29), Mulgrave River, 17°11'S, 145°43'E, 17 January 1984, S.H. Midgley; QM I.30461, 2(32–34), Little Falls Creek, Mossman, 16°23'S, 145°20'E 27, September, 1995, P. Hales; QM I.30467, 3(33–49), Saltwater Creek, Mossman, 16°25'S, 145°21'E, 4 October, 1995, P. Hales; QM I.30469, 3(37–47), Bamboo Creek, Mossman, 16°21'S, 145°23'E, 10 October, 1995, P. Hales; QM I.30471, 6(19–45), Whyanbeel Creek, Miallo, 16°24'S, 145°21'E 27 September, 1995, P. Hales; QM I.30473, 4(28–43), Chinamans Creek, Miallo, 16°22'S, 145°21'E, 3 October, 1995, P. Hales; QM I.30478, 5(21–40), Boulder Creek, Miallo, 16°22'S, 145°20'E, 3 October, 1995, P. Hales; QM I.35990, 5(31–48), Saltwater Creek, 16°25'S, 145°21’E, 9 June 2004, F. Kroon.

Diagnosis: Mental fraenum bilobed, with lateral lobes broad and attached to chin, with a posteromedian attachment sometimes giving the appearance of a third lobe; predorsal area partly scaled, midline scales extending no farther forward than posterior preopercular margin; cheek, operculum, pectoral base, prepelvic area and anterior midline of belly naked; first dorsal fin with one or two large black spots posteriorly; second dorsal-fin rays usually I,10; anal-fin rays I,8; pectoral-fin rays usually 16–17; predorsal scale count 2–14; cheek papilla lines composed of single row of papillae; papilla line 6 absent and vertebrae usually 12+16.

Description: Based on 65 specimens 25–61 mm SL. First dorsal spines 5(1), 6(63)*; gill rakers on outer face of first arch 0+0+6, 0+1+5(2), 0+1+6(3), 0+1+7(1), 1+1+6(2), 1+1+7(1); segmented caudal-fin rays 16(2), 17(35*); branched caudal rays 7/6(1), 7/7(6*); vertebrae 11+16(1), 11+17(2), 12+16(20); predorsal scale count 2(2), 3(1), 4(1), 5(2), 6(2), 7(7), 8(2*), 9(14), 10(8), 11(8), 12(4), 14(1); longitudinal scale count 27(1), 28(4), 29(16), 30(23), 31(5*), 32(2); transverse scale count (TRB) 8.5(26*), 9.5(23). second dorsal-fin rays usually I,10; anal-fin rays I,8; pectoral-fin rays usually 16–17 (see Tables 1–3 ).

Head depressed, 27.2–30.6%SL. Snout short, broadly rounded in dorsal view; straight to convex in side view; 8.2–8.8% SL. Cheeks tapering. Interorbital narrow, less than eye length. Eye about 1–1.2 in snout, 7.2–8.6% SL. Small bump below anterior nostril present. Anterior nostril at end of short tube, just above upper lip. Posterior nostril 1–2 nostril diameters from eye and 1–2 from anterior nostril, posterior nostril varying from midway between eye and upper lip to closer to eye than upper lip. Posterior preopercular margin without spine. Preoperculum short, distance from end of eye to upper posterior preopercular margin slightly less than eye. Mental fraenum bilobed, with lateral lobes broad and attached to chin and with a posteromedian attachment sometimes giving the appearance of a third lobe. Mouth small, reaching to below anterior quarter of eye; jaws forming an angle of 35–40° with body axis; upper margin of upper jaw in line with middle to just above lower margin of eye. Upper jaw 10–12.1% SL. Gill opening reaching to below or just behind posterior preopercular margin. Teeth in upper jaw: outer row of teeth conical, slightly enlarged and wideset, 2–3 inner rows of smaller depressible, inwardly directed teeth, innermost row larger than middle row. Teeth in lower jaw: teeth in outer row conical, slightly enlarged and wideset anteriorly, 2–3 inner rows of smaller depressible teeth. Tongue tip with shallow notch, distinctly bilobed. Gill rakers on outer face of first arch short and triangular; longest raker about one-third filament length. Rakers on inner face of first arch and other arches short and denticulate. Predorsal area partly scaled, often with scales at side extending farther forward than scales on midline, sides scaled forward to a point above middle of operculum to just behind eye, midline naked or with scales extending forward to just before posterior preopercular margin, midline sometimes with some small scales forward to above posterior end of operculum and area immediately adjacent to midline naked, but partly scaled along sides of nape. Cheek naked. Operculum naked. Pectoral base naked. Prepelvic area naked. Belly with a large naked area behind pelvic insertion. Body covered mostly with large ctenoid scales, cycloid anterior of line from second dorsal origin to upper pectoral origin and on belly. First dorsal fin low, with rounded margin; spines 3–5 extending beyond other spines when fin depressed; origin well behind pelvic insertion. Second dorsal fin subequal in height to first dorsal fin. Anal fin slightly lower than dorsal fins. Pectoral fin with rounded margin, reaching to above anal origin or slightly beyond. Pelvic disc moderately thick, slightly longer than wide, reaching to below anus; fifth ray with 6–9 terminal tips.

Head pores: nasal pore above posterior nostril; anterior interorbital pore present; posterior interorbital pore present; postorbital pore behind eye present; infraorbital pore below postorbital present; lateral canal pore above preoperculum present; lateral canal pore above posterior preopercular margin absent; terminal lateral canal pore above operculum present; short tube above operculum, with pore at each end present, represented by open trough or often absent in small specimens (below 20 mm SL); 3 preopercular pores, upper in line with lower margin of eye; middle pore closer to lower pore than to upper.

Sensory Papillae: ( Figure 7 ; lines listed below all composed of single row of papillae).

Line 1 (before nasal pore) present. Line 2 (between nasal pores) curved, with gap at midline of snout. Line 5 (suborbital) reaching to or almost to line 7 before eye. Line 6 (suborbital branch) absent. Lines 7, 9, 10 (VL cheek rows) each reaching near to posterior preopercular margin. Lines 8 and 11 (VT row) ending near to preopercular margin. Line 12 (Outer POP-mandibular) with a gap at end of jaws. Line 13 (Inner POP-mandibular) slightly curved near end of jaws. Line 20 (OP VT) branched ventrally. Line 21 (Upper OT) curved. Line 22 (Lower OT) without branches, not connected to line 21. Several vertical papillae rows on belly. A single curved line anteriorly on most body scales (often obscure dorsally and posteriorly); chin papillae in 5 to 7 transverse rows laterally and 2–3 rows medially, forming a bilobed patch, with the lobes directed posteriorly.

Coloration: Head and body brown. Head with small scattered dark brown spots; a broad stripe from anteroventral margin of eye to above middle of upper lip, not extending onto lip; a short stripe from posteroventral margin of eye extending a short distance onto cheek, often with a dark brown spot posteroventrally to bar (sometimes connected to bar); chin and isthmus dark brown, rest of ventral surface of head lighter; mental frenum dark brown; lips dark brown except for white at posterior tip, no bars crossing lips. Body dark brown from midside dorsally and pale brown ventrally; an irregular shaped dark brown spot or bar above pectoral base. An oblique brown bar or spot on belly below anterior part of first dorsal fin, extending from midside ventrally; an irregular brown spot below posterior part of first dorsal fin, extending a short distance dorsally from midside; a series of elongate spots posterior to first dorsal fin on midside, each covering 2–3 scales in longitudinal direction along midside, usually not extending onto scales above or below midside; first spot below first dorsal origin, covering 2–3 scales, second below and just before middle of second dorsal fin, covering 2 scales, third spot covering 2–3 scales below end of second dorsal fin, fourth covering 2 scales anteriorly on middle of caudal peduncle, fifth covering two scales on middle of caudal peduncle, sixth at posterior end of caudal peduncle, expanding into a short vertical bar on caudal fin base (bar on caudal fin base sometimes separate from caudal peduncle spot); a series of V-shaped saddles dorsally below dorsal fin, arranged above space between midside spots. Pectoral fin base with a short brown bar or small spot extending onto base of pectoral rays. First dorsal fin with scattered black spots in 2–3 oblique rows, posterior end of first dorsal fin with larger black spot surrounding middle of sixth spine extending posteriorly to end of fin (often separated into two spots). Second dorsal fin with black spots forming 2 rows ventrally, distal margin of fin dark brown. Pectoral fins brown without spots. Caudal fin with central rays covered with brown spots forming wavy bands (usually 4–6) on dorsal two-thirds of fin, ventral and dorsal thirds gray to light brown. Anal fin whitish basally, distal one-quarter to one-third dark brown. Pelvic fins gray to dark brown.

Distribution: Glossogobius bellendenensis is known only from the Russell, Mulgrave and Mossman rivers and creeks near Cairns in north-eastern Queensland from above tidal influence to altitudes of a few hundred metres. The species is typically found in clear, flowing streams, with coarse sand and medium to large sized rocks, in open or in forested areas.

Similarity to other species: Glossogobius bellendenensis is readily distinguished from other species of Glossogobius in dorsal and anal-ray counts, reduced predorsal scale coverage, absence of scales of prepelvic area and pectoral base and distinctive shape of the mental frenum. It shares most of those characteristics with Glossogobius muscorum from the Fly River in New Guinea. Glossogobius bellendensis differs from that species in coloration, in usually having 12+16 vertebrae (versus 11+17), and a trilobed mental frenum (versus bilobed). The coloration differences include lacking a horizontal brown stripe on the cheek below the eye, an oval brown spot on the anteromedian margin of the operculum and white on the posterior end of lips, characteristic of G. muscorum . It addition there are two large spots on the midside on the belly (versus one large blotch on the side of the belly).

The species can be confused with Glossogobius concavifrons , which has scales on the pectoral base and prepelvic area, predorsal scales reaching to near eye, more numerous precaudal vertebrae (13–15) and more compressed head. Currently the two species are not known to be sympatric. Glossogobius concavifrons is known from rivers of western Cape York to Arnhem Land in Australia and southern New Guinea. Separation of juveniles below 20 mm SL is difficult because the scales are not well developed in Glossogobius concavifrons at that size.

Remarks: The predorsal scales development varies considerably in this species. Specimens from the Mossman River generally have scales on the midline of the nape extending forward to between a point above the anterior operculum and posterior preoperculum, while specimens from the Russell and Mulgrave rivers often lack scales on the midline or have scales extending up to above the middle of the operculum, rarely to above the posterior preopercular margin. Specimens from Whyanbeel Creek, Miallo (QM I.30471) are atypical in having 3 of 6 specimens with an anal ray count of I,7 and the others with I,8. Because of the slight differences between the Russell-Mulgrave and Mossman specimens, the specimens from the Mossman area are excluded from the type series.

Kroon and Johnson (2006) document Queensland records of this species. Although the species currently is restricted in its distribution, it may have been mistaken for juveniles of other species because of the small size of the species. Consequently it is likely to be more widely distributed in Australia.

Etymology: Named for the Bellenden Ker Range, where the species was first discovered.

Figures

FIGURE 5. Holotype of Glossogobius bellendenensis, AMS I. 22715 – 004, 43 mm SL.

FIGURE 6. Freshly collected paratype of Glossogobius bellendenensis from Mulgrave River, Queensland, AMS I. 22712 – 001

FIGURE 7. Sensory papilla pattern of Glossogobius bellendenensis based on paratype, AMS I. 22061 – 001, 50 mm SL.

FIGURE 8. a. Mental frenum of Glossogobius bellendenensis based on holotype; b. Mental frenum of Glossogobius muscorum based on holotype.