Gulf Grunter, Scortum ogilbyi Whitley 1951


Gulf Grunter, Scortum ogilbyi. Source: Glynn Aland. License: all rights reserved

Summary:
A large silvery-grey to blackish grunter which usually has irregular black blotches in the sides. The body is paler below and a pale stripe runs from the snout to below the eye.

Cite this page as:
Martin F. Gomon, Scortum ogilbyi in Fishes of Australia, accessed 16 Nov 2018, http://fishesofaustralia.net.au/home/species/2521

Gulf Grunter, Scortum ogilbyi Whitley 1951

More Info


Distribution

Known only from rivers flowing into the Gulf of Carpentaria from Roper River, NT to Jackson River, QLD; a tropical species inhabiting turbid water of large freshwater rivers and waterholes as well as smaller and clearer tributaries.

Features

Meristic features: Dorsal fin XIII, 11-13; Anal fin III, 8-10; Pectoral fin 15-17; Lateral line scales 50-55.

Body moderately deep, 2.4-2.8 in SL, ovate, slightly compressed, more so in adults; dorsal profile much more pronounced than ventral in juveniles, only slightly more in adults, nearly straight from snout in interorbital region, concave above eyes, then convex to dorsal origin; dorsal profile of adults straighter overall; ventral profile straight from lower jaw to anus in young, gently curved in adults; more pronounced in larger specimens. Snout blunt, more so in adults. Jaws equal; gape oblique; maxillary reaching to vertical through posterior nostril or anterior of eye; teeth partially flattened, depressible; in bands with outer row enlarged; teeth variably present on vomers in adults, lacking on palatines. Lacrimal serrate; strongly in young; serrations obscure or lacking in larger individuals. Preoperculum serrate; serrations stronger on angle and vertical edge; becoming weaker with age. Lower opercular spine stronger and longer; not extending beyond edge of opercular lobe. Posttemporal exposed; posterior edge serrate. Cleithrum exposed; posterior edge serrate; serrations weaker with age; scales on side. Supracleithrum exposed.

Scales small, finely ctenoid; lateral line continuous, smoothly curved; 70-76 scales in a series above lateral line.

Dorsal fin continuous, spinous portion arched; first spine short; fifth or sixth longest, 2.0-2.2 in HL, those following decreasing gradually to the penultimate, which is slightly shorter than ultimate, longest dorsal spines longer than longest dorsal rays; soft dorsal rounded. Soft anal rounded in young, more angular in adults. Pectoral fins asymmetrically pointed; fourth or fifth rays longest. Pelvic fins pointed; Caudal fin emarginate.

Size

To 40cm SL, commonly to 25cm.

Colour

Silvery-grey to nearly blackish on sides usually with irregular black blotches that can be flashed on and off and may vary daily in position and number. Whitish ventrally. Pearly stripe from below eye to snout.

Feeding

Feeds on fishes, crustaceans, insects and molluscs.

Biology

Little is known of the reproductive biology of this species but it is likely to be oviparous producing demersal eggs.

Remarks

Previously considered a synonym of Scortum hilli.

Similar Species


Species Citation

Scortum ogilbyi Whitley, 1951, Rec. Aust. Mus. 22(4): 397. Type locality: Norman River, QLD.

Author

Martin F. Gomon

Gulf Grunter, Scortum ogilbyi Whitley 1951

References


Allen, G.R., Midgley, S.H. & Allen, M. (2002). Field guide to the freshwater fishes of Australia.  Perth : Western Australian Museum 394 pp.

Whitley, G.P. (1951). Studies in Ichthyology No. 15. Rec. Aust. Mus. 22(4): 389–408 figs 1–14 

Quick Facts


CAAB Code:37321035

Habitat:large freshwater rivers

Max Size:40 cm SL

Native:endemic

Native:Endemic

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