Rock Flathead, Platycephalus laevigatus Cuvier 1829


Other Names: Black Flathead, Grass Flathead, Grassy Flathead, King Flathead, Marbled-bellied Flathead, Port Albert Flathead, Rock Flathead, Smooth Flathead, Southern Rock Flathead

A Rock Flathead, Platycephalus laevigatus, at Indented Head, Port Phillip, Victoria. Source: Sarah Speight / Flickr. License: CC by Attribution-NonCommercial-ShareAlike

Summary:

A large slender flathead with a small, narrow, slightly flattened head; corner of gill cover with two spines, upper longer than lower.

Usually greenish to pale brown above, pale below,with darker bands, a broken mid-lateral stripe and a yellow tail covered in dusky spots.. Some individuals have a spotted or marbled pattern.


Cite this page as:
CSIRO Marine & Atmospheric Research & Dianne J. Bray, Platycephalus laevigatus in Fishes of Australia, accessed 18 Oct 2018, http://fishesofaustralia.net.au/home/species/3360

Rock Flathead, Platycephalus laevigatus Cuvier 1829

More Info


Distribution

Common in coastal waters of southern Australia from off Greenwell Point (New South Wales) to Geographe Bay (Western Australia), including Tasmania.

Demersal on rocky reef, sand and seagrass bottoms in shallow, inshore waters to at least 20 m depth; prefers hard, weedy bottoms or seagrass (Zostera) beds to rest on rather than burying in soft bottoms.

The numbers of Rock Flathead are increasing in southeastern Tasmania.

Features

Meristic features: Dorsal fin IX (rarely VIII), 14 or 15; Anal fin 14 or 15 (rarely 13); Caudal fin 15; Pectoral fin 18-21; Pelvic fin I, 5; Lateral line scales (pored) 81-92.

Body elongate, slightly depressed. Head small (length 25-28% SL), narrow, slightly depressed, smooth, without ridges; eyes large (19-22% HL), situated well anterior to middle of head, iris lappet single lobed; mouth large with small, pointed teeth in broad band on jaws, no enlarged canines; two moderate-sized preopercular spines at angle of preopercle, lower shorter than upper; 2 gill rakers on lower limb, 7 or 8 on upper limb of first gill arch; interopecular flap present.

Scales very small, finely ctenoid, covering body and most of head behind eyes, absent from opecular flap; lateral line nearly straight; lateral line scales subequal to adjacent scales on side, without spines or ridges.

First dorsal fin spinous with short base, first spine very short, detached, longest spines subequal to length of second dorsal-fin rays. Second dorsal fin with moderately long base. Anal fin similar in shape, opposite and slightly shorter-based than second dorsal fin. Caudal fin rounded. Pectoral fins of moderate size. Pelvic fins subequal in length to, and based below centre of, pectoral fins. Swim bladder absent.

Size

Maximum length at least 60 cm; maximum weight at least 2 kg.

Colour

Greenish to pale sandy dorsally, usually with dark vertical bands and a longitudinal stripe mid-laterally (sometimes broken into blotches), or with body covered with moderate-sized spots, marbled in appearance rather than spotted; pale ventrally with fewer markings. Caudal fin yellow with dense dark spots; anal fin plain; other fins spotted along spines or rays. Juveniles with strong pattern of bands and dark bars.

Feeding

Rock Flathead are carnivores, and feed mostly on other fishes, as well as on large benthic crustaceans. They are most active at dusk and night.

Fisheries

Of minor commercial importance, and taken in small numbers in beach seines and gillnets.

Species Citation

Platycephalus laevigatus Cuvier, 1829, In Cuvier & Valenciennes, Hist. nat. Poiss. 4: 248, Western Port, Victoria.

Author

CSIRO Marine & Atmospheric Research & Dianne J. Bray

Rock Flathead, Platycephalus laevigatus Cuvier 1829

References


Eschmeyer, W.N. 2008. The Catalogue of Fishes on-line. (California Academy of Sciences: San Francisco) Available from: http://www.calacademy.org/research/ichthyology/catalog/fishcatmain.asp (15 March, 2008).

Gomon, M.F., Glover, J.C.M. & Kuiter, R.H. 1994. The Fishes of Australia's South Coast. State Print, Adelaide, 992 pp.

Hoese, D.F., Bray, D.J., Paxton, J.R. & Allen, G.R. 2006. Fishes. In Beesley, P.L. & A. Wells (eds.) Zoological Catalogue of Australia. Volume 35. Parts 1-3. Australian Biological Resources Study and CSIRO Publishing, 2248 pp.

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

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.

Last, P.L., W.T. White, D.C. Gledhill, A.J. Hobday, R. Brown, G.J. Edgar & G. Pecl. 2011. Long-term shifts in abundance and distribution of a temperate fish fauna: a response to climate change and fishing practices. Global Ecol. Biogeogr. 20: 58–72.

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:37296006

Danger:Venomous spines

Depth:1-20 m

Fishing:Minor commercial

Habitat:Rocky reef, sand, seagrass

Max Size:60 cm; 2 kg

Native:Endemic

Species Image Gallery

Species Maps

CAAB distribution map