Glossogobius, Gill, 1859

Hoese, Douglass F. & Hammer, Michael P., 2021, A review of the Glossogobius giuris complex in Australia, with wider discussion on nomenclature and possible synonymies, Zootaxa 4974 (1), pp. 79-115 : 112

Key to species of glossogobius from australia

1. A pair of barbels at tip of chin. Estuarine and lower reaches of rivers from Weipa to norther eastern Queensland, widespread in western Pacific northward to Japan and east to Fiji................................................ G. bicirrhosus

1. No barbels at tip of chin (mental fraenum may be bilobed)..................................................... 2

2. Cheek papillae arranged in 8 or more vertical rows. Gill rakers on outer face of first arch elongate, usually 12–16. Mangroves from north-western Australia to north-eastern eastern Queensland, widespread in western Pacific......... G. circumspectus

2. Cheek papillae arranged in longitudinal rows, or rarely in few short vertical rows. Rakers on outer face of first arch short, 5–12................................................................................................ 3

3. Predorsal naked or scaled forward to above operculum, scale rows 0–7. A conspicuous black spot at posterior end of first dorsal fin. Midline of body with thin elongate spots, sometimes forming a broken stripe. Lower attachment of gill membranes behind posterior preopercular margin. Maximum size 50 mm SL...................................................... 4

3. Predorsal scaled forward to above preoperculum, scale rows 13–30. No spot or small black spot at posterior end of first dorsal fin. Midline of body with deep elongate spots or blotches. Lower attachment of gill membrane under or before posterior preopercular margin. Maximum size up to 300 mm SL.......................................................... 5

4. Predorsal largely naked, a few scales at side of nape. Anal rays I, 6–7. No distinct lateral canal tube with pore at each end above operculum. Longitudinal scale count 24–29. Transverse scale count 7–8.5. Body with elongate spots along midside forming a broken stripe. Western rivers of Cape York region, Queensland and Arnhem Land, Northern Territory and southern New Guinea....................................................................................... G. nanus

4. Midline of predorsal with 2–7 scale rows, reaching forward to above operculum. A lateral canal tube with pore at each end above operculum. Anal rays usually I, 8. Longitudinal scale count 29–31. Transverse scale count usually 8.5–10.5. Body with slightly elongate thin spots, with bands extending from spots. Endemic to Wet Tropics (Mossman to Russell-Mulgrave System), north-eastern Queensland.`............................................................... G. bellendenensis

5. Head compressed. Second dorsal rays I,10–12. No gill rakers developed on upper part of outer face of first arch, lower rakers 6–8. Precaudal vertebrae 13-15. Western rivers of Cape York, Queensland, Cato and Goyder river systems of the Northern Territory and southern rivers of New Guinea...................................................…… G. concavifrons

5. Head depressed. Second dorsal I,9. Usually 1–2 rakers on upper part of outer face of first arch, rakers usually 8–12. Precaudal vertebrae 10-11....................................................................................... 6

6. Predorsal scales large, usually in 12–16 rows. An infraorbital pore behind eye and 4 lateral canal pores above preoperculum and operculum. Coastal streams of north-eastern Queensland and widespread in northern New Guinea, ranging to Japan. G. illimis

6. Predorsal scales small, usually in 17–30 rows. An infraorbital pore and 2 lateral canal pores above preoperculum and operculum................................................................................................ 7

7. A line of papillae from middle of upper jaw to infraorbital pore behind eye with distinct posterior branch under eye (line 6). Longitudinal lines 7, 9 and 10 on cheek composed of multiple rows of papillae, except in small juveniles................ 8

7. Line of papillae from middle of upper jaw to infraorbital pore without branch. Longitudinal lines 7, 9 and 10 on cheek composed of single row of papillae........................................................................... 9

8. Operculum with few or no scales anteriorly on operculum. Predorsal scales reach to above preoperculum with a gap behind the posterior interorbital pore. Chin uniformly pigmented, often with a V-shaped dark bar behind chin; often with black marking on distal margins of first dorsal fin. North-western Northern Territory and Western Australia, with populations extending well inland........................................................................................ G. giuris

8. Operculum with scales extending about ⅔ to ¾ of upper operculum in two to four rows. Predorsal scaled to or almost up to posterior interorbital pore, often obscuring postorbital pore. Chin with no melanophores centrally or scattered melanophores and bordered laterally by dark longitudinal stripes; pigment behind chin light or dark without a distinct transverse band, no prominent black marks on distal margin of first dorsal fin. Coastal rivers of eastern Queensland and Northern Territory ………..……. ……......................................................................... G. laticeps

9. Chin without a distinct bilobed mental frenum. Snout long 10–11% SL. Head large, 34–36% SL. Mouth large reaching to below anterior margin of pupil, 11–13% SL. Distance from posterior end of eye to posterior preopercular margin long, 7–8% SL. No bump on snout under anterior nostril. Predorsal scales usually more than 24. Rivers of northern Australia east of Darwin area across to north-eastern Queensland ................................................................ G. aureus

9. Chin with a distinct bilobed mental frenum. Snout short, 9–10% SL. Head short, 30–32% SL. Mouth reaching to below anterior margin of eye, 9–11% SL. Distance from posterior end of eye to posterior preopercular margin short, 5–6% SL. A small bump on snout below anterior nostril. Predorsal scales usually less than 24. Confined to rivers of northern Australia and southern New Guinea, but not known from eastern Queensland..................................................... G. munroi