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 greenish to pale brown flathead with darker bands along the back, a broken mid-lateral stripe and a yellow tail covered in dusky spots. Some individuals have a spotted or marbled pattern. The Rock Flathead has a small, narrow, slightly flattened head, and the upper spine on the corner of the gill cover is longer than the lower spine.


Cite this page as:
CSIRO Marine & Atmospheric Research & Bray, D.J. 2020, Platycephalus laevigatus in Fishes of Australia, accessed 24 Sep 2020, http://136.154.202.208/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.

Inhabits rocky reef, sand and seagrass areas in shallow, inshore waters to a depth of at least 20 m. Rather than burying in the sustrate, this species prefers resting on hard, weedy areas or seagrass (Zostera) beds.

Features

Dorsal fin IX (rarely VIII), 14-15; Anal fin 13-15 (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.

Remarks


The numbers of Rock Flathead are reportedly increasing in southeastern Tasmania.

Species Citation

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

Author

CSIRO Marine & Atmospheric Research & Bray, D.J. 2020

Resources

Atlas of Living Australia

Rock Flathead, Platycephalus laevigatus Cuvier 1829

References


Castelnau, F.L. de 1872. Contribution to the ichthyology of Australia. 1. The Melbourne fish market. Proceedings of the Zoological and Acclimatisation Society of Victoria 1: 29-242 1 pl. (described as Platycephalus proximus)

Coleman, N. & Mobley, M. 1984. Diets of commercially exploited fish from Bass Strait and adjacent Victorian waters, southeastern Australia. Australian Journal of Marine and Freshwater Research 35(5): 549-560.

Coulson, P.G., Hall, N.G. & Potter, I.C. 2017. Variations in biological characteristics of temperate gonochoristic species of Platycephalidae and their implications: A review. Estuarine and Coastal Shelf Science 190: 50-68.

Cuvier, G.L. in Cuvier, G.L. & Valenciennes, A. 1829. Histoire Naturelle des Poissons. Paris : Levrault Vol. 4 518 pp. pls 72-99. See ref at BHL

Edgar, G.J. & Shaw, C. 1995. The production and tropic ecology of shallow-water fish assemblages in Southern Australia. II. Diets of fishes and tropic relationships between fishes and benthos at Western Port, Victoria. Journal of Experimental Marine Biology and Ecology 194: 83-106.

Gomon, M.F. 2008. Family Platycephalidae. pp. 515-521 in Gomon, M.F., Bray, D.J. & Kuiter, R.H. (eds). Fishes of Australia's Southern Coast. Sydney : Reed New Holland 928 pp.

Grant, E.M. 2002. Guide to Fishes. Redcliffe : EM Grant Pty Ltd 880 pp.

Hindell, J.S., Jenkins, G.P. & Keough, M.J. 2000. Variability in abundances of fishes associated with seagrass habitats in relation to diets of predatory fishes. Marine Biology 136(4): 725-737.

Hutchins, B. & Swainston, R. 1986. Sea Fishes of Southern Australia. Swainston Publishing, Perth. 179 pp. (as Leviprora laevigatus)

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.

Imamura, H. 2015. Taxonomic revision of the flathead fish genus Platycephalus Bloch, 1785 (Teleostei: Platycephalidae) from Australia, with description of a new species. Zootaxa 3904(2): 151–207

Klumpp, D.W. & Nichols, P.D. 1983. A study of food chains in seagrass communities II. Food of the rock flathead, Platycephalus laevigatus Cuvier, a major predator in a Posidonia australis seagrass bed. Australian Journal of Marine and Freshwater Research 34(5): 745-754.

Kuiter, R.H. 1993. Coastal Fishes of South-eastern Australia. Bathurst : Crawford House Press 437 pp. 

Kuiter, R.H. 1994. Family Platycephalidae. pp. 514-523 figs 458-465 in Gomon, M.F., Glover, C.J.M. & Kuiter, R.H. (eds). The Fishes of Australia's South Coast. Adelaide : State Printer 992 pp. 810 figs. 

Kuiter, R.H. 1996. Guide to Sea Fishes of Australia. A comprehensive reference for divers and fishermen. Sydney, NSW, Australia : New Holland Publishers xvii, 434 pp.

Last, P.R., Scott, E.O.G. & Talbot, F.H. 1983. Fishes of Tasmania. Hobart : Tasmanian Fisheries Development Authority 563 pp. figs.

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

Roughley, T.C. 1957. Fish and Fisheries of Australia. Sydney : Angus & Robertson 341 pp.

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:Reef associated, sand/seagrass

Max Size:60 cm; 2 kg

Native:Endemic

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CAAB distribution map