Southern Bluespotted Flathead, Platycephalus speculator Klunzinger 1872


Other Names: Bluespot Flathead, Bluespot Flathead, Blue-spot Flathead, Bluespotted Flathead, Castelnaus Flathead, Castelnau's Flathead, Deepwater Flathead, Deep-water Flathead, King Flathead, Lakes Entrance Flathead, Longnose Flathead, Shovelnose Flathead, Southern Dusky Flathead, Southern Flathead, Yank Flathead

A Southern Bluespotted Flathead, Platycephalus speculator, at Point Cook, Port Phillip, Victoria, April 2017. Source: Sascha Schultz / iNaturalist.org. License: CC by Attribution-NonCommercial

Summary:
A large sandy to dark brown or greyish flathead, paler below, with small scattered blue to whitish spots, and often dark spots and blotches, and caudal fin margin with 3-5 large, round, similar-sized black white-edged spots, fin otherwise with dusky brown blotches.

This is the largest flathead in Victoria's Port Phillip, and is highly prized by both commercial and recreational fishes.

Cite this page as:
CSIRO Marine & Atmospheric Research & Dianne J. Bray, Platycephalus speculator in Fishes of Australia, accessed 21 Nov 2018, http://fishesofaustralia.net.au/home/species/3364

Southern Bluespotted Flathead, Platycephalus speculator Klunzinger 1872

More Info


Distribution

Coastal waters of southeastern Australia from Cape Everard (Victoria) to Kalbarri (Western Australia), including around Tasmania. Demersal on soft bottoms and weed beds in shallow coastal waters to depths of about 30 m; particularly common in shallow protected bays.

Features

Meristic features: Dorsal fin VIII (rarely IX), 14 (rarely 13); Anal fin 14; Caudal fin 15; Pectoral fin 19-21 (rarely 18); Pelvic fin I, 5; Lateral line scales (pored) 80-93.

Body elongate, slightly depressed. Head large (length 28-34% SL), depressed, with several low, mostly spineless ridges; eyes moderately large (16-22% HL) with broad, rounded iris lappet; mouth large with small pointed teeth on jaws, in one or two rows on vomer and in a single row on each palatine, no enlarged canines; two strong preopercular spines at angle of preopercle, lower spine slightly longer than upper; gill rakers on lower limb of first arch long and slender, 3 or 4 on lower limb, 10-12 on upper limb; interopercular flap present.

Scales small, finely ctenoid, covering body and most of head behind eyes; lateral line scales slightly larger than adjacent scales on side, ~95 oblique rows of scales above lateral line, anteriormost scale with small spine or ridge.

First dorsal fin spinous with short base, first spine very short, detached, following spines much longer. Second dorsal fin with moderately long base, anterior rays longest, only slightly shorter than longest first dorsal-fin spine. Anal fin similar in shape, opposite and slightly longer-based than second dorsal fin. Caudal fin truncate to rounded. Pectoral fins moderately small. Pelvic fins long, broad, based below centre of pectoral fins. Swim bladder absent.

Size

Maximum length at least 90 cm TL; maximum weight at least 8 kg.

Colour

Sandy to dark brown dorsally with sparsely scattered small blue to white spots often intermingled with dark spots and blotches; no large dark blotch on underside of operculum; pale ventrally. Caudal-fin margin with 3-5 large, round, similar-sized black spots surrounded by white, remainder of fin with dusky brown blotches; pectoral and pelvic fins with faint spots.

Feeding

Carnivore - feeds mostly on fishes, and also consumes large benthic crustaceans.

Biology

Breeds mostly during the summer and early autumn (December to March). Although spawning typically occurs at sea, some females spawn within estuaries. Larval development has been described in Hyndes, Neira & Potter (1992).

Fisheries

Caught in beach seines, gill nets and haul nets along the southern coast; probably the most commonly marketed flathead in Western Australia.

Species Citation

Platycephalus speculator Klunzinger, 1872, Arch. Naturgesch. 38(1): 28, Hobson's Bay, Victoria.

Author

CSIRO Marine & Atmospheric Research & Dianne J. Bray

Southern Bluespotted Flathead, Platycephalus speculator Klunzinger 1872

References


Gomon, M.F. 2008. Family Platycephalidae. In: Gomon, M.F., Bray, D.J. & Kuiter, R.H. The Fishes of Australia's Southern Coast. Reed new Holland, Chatswood, Australia.

Hutchins, B. & Swainston, R. 1986. Sea Fishes of Southern Australia. Swainston Publishing, Perth. 179 pp.

Hyndes, G.A., Loneragan, N.R. & Potter, I.C. 1992. Influence of sectioning otoliths on marginal increment trends and age and growth estimates for the flathead Platycephalus speculator. Fishery Bulletin 90: 276-284.

Hyndes, G.A., Neira, F.J. & Potter, I.C. 1992. Reproductive biology and early life history of the marine teleost Platycephalus speculator Klunzinger (Platycephalidae) in a temperate Australian estuary. Journal of Fish Biology 40: 859-874.

Imamura, H. 2006. Rediagnosis of the marbled flathead, Platycephalus marmoratus (Actinopterygii: Teleostei: Platycephalidae), with comments on the composition of the type series. Species Diversity 11: 295-306.

Kuiter, R.H. 1993. Coastal fishes of south-eastern Australia. University of Hawaii Press, Honolulu. 437 p.

Yearsley, G.K., Last, P.R. & Ward, R.D. 2001. Australian Seafood Handbook: an identification guide to domestic species. FRDC / CSIRO Marine Research, 469 pp.

Quick Facts


CAAB Code:37296037

Danger:Venomous spines

Depth:1-30 m

Fishing:Commercial, recreational

Habitat:Soft bottoms, weed beds

Max Size:90 cm; 8 kg

Native:Endemic

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CAAB distribution map