Rusty Flathead, Inegocia japonica (Tilesius 1812)

Other Names: Japanese Flathead, Lizard Flathead

Summary:

A smallish orange to brown flathead, with a flecked or mottled pattern, a pale underside, and many dark spots of varying sizes on the tail.

Cite this page as:

CSIRO Marine & Atmospheric Research & Bray, D.J. 2017, Inegocia japonica in Fishes of Australia, accessed 19 Apr 2024, https://fishesofaustralia.net.au/home/species/2179

Rusty Flathead, Inegocia japonica (Tilesius 1812)

More Info

Distribution	Continental shelf of northern Australia from Moreton Bay, Queensland, to the Northwest Shelf and possibly to Cockburn Sound, Western Australia. Elsewhere the species is widespread in the Indo-west Pacific, including Papua New Guinea, Indonesia, Philippines, southern Japan, South China Sea, Gulf of Thailand to India and Sri Lanka. Demersal in bays and coastal waters to depths between 5-85 m.
Features	Dorsal fin IX or I,VIII, 11-13 (usually 12); Anal fin 11-13 (usually 12); Pectoral fin 19-21 (usually 19 or 20); Pelvic fin I, 5; Lateral line scales (pored) 51-55 (usually 52 or 53). Body elongate, moderately depressed. Head large (length ~34-35% SL), moderately depressed, supraorbital ridge smooth anteriorly, with serrations over posterior half of eye; preorbital spine absent; a single preocular spine; suborbital ridge usually smooth except for 2 spines under eye (specimens from Indonesia and Australia frequently have a few additional small serrations); Lower side of head bicarinate; ocular flap absent; teeth on jaws low and fine, teeth on vomer in two parallel longitudinal patches; preopercular spines usually 3, upper preopercular spine short, subequal with next; small accessory spine usually present; interopercular flap elongate, pointed; Total gill rakers on first arch 5-7 (usually 6). Scales small, finely ctenoid dorsally, cycloid ventrally, covering body and most of head behind eyes; Oblique scale rows slanting downward above lateral line closely approximate number of lateral-line scales. Lateral-line scales 51-55 (usually 52 or 53), anterior 2-21 scales bearing a small spine or ridge. First dorsal fin spinous, base length moderate, first spine very short, connected by a low membrane to second, following spines much longer. Second dorsal fin base longer than first, anterior rays longest, nearly as long as longest first dorsal spines. Anal fin similar in shape, opposite and slightly longer-based than second dorsal fin. Caudal fin rounded.
Size	Maximum total length about 25 cm, commonly to 20 cm TL.
Colour	Head and body orange-brown or grey above, whitish below, about 6 obscure dark bands across back. Caudal fin pale with about 3 series of black spots over entire fin, becoming larger and more elongated ventrally; pectoral and pelvic fins with large brown spots, sometimes forming weak bands.
Feeding	Presumably feeds on other fishes and invertebrates.
Biology	The Rusty Flathead undergoes a protandrous sex change, whereby most mature males change sex into females. Individuals reportedly have overlapping home ranges and the species is thought to have a promiscuous mating system.
Fisheries	Taken by trawls over sand and mud bottom.
Conservation
Etymology	The species name japonica is for Japan, the type locality.
Species Citation	Platycephalus japonicus Cuvier 1829 (ex Tilesius) Histoire naturelle des poissons 4: 1829: 256. Type locality: Nagasaki, Japan.
Author	CSIRO Marine & Atmospheric Research & Bray, D.J. 2017
Resources	Australian Faunal Directory

Rusty Flathead, Inegocia japonica (Tilesius 1812)

References

Allen, G.R. 1997. Marine fishes of tropical Australia and south-east Asia. Western Australian Museum, Perth. 1-292.

Allen, G.R. & R. Swainston. 1988. The marine fishes of north-western Australia. A field guide for anglers and divers. Western Australian Museum, Perth. The marine fishes of north-western Australia.: I-vi + 1-201, 1-70. (as Suggrundus japonica)

Blaber, S.J.M., Brewer, D.T. & Harris, A.N. 1994. Distribution, biomass and community structure of demersal fishes of the Gulf of Carpentaria, Australia. Australian Journal of Marine and Freshwater Research 45(3): 375-396, figs 1-7

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

Fujii, T. 1971. Hermaphroditism and sex reversal in fishes of the platycephalidae. II. Kumococius detrusus and Inegocia japonica. Japanese Journal of Ichthyology 18: 109-117. https://doi.org/10.11369/jji1950.18.109, open access

Gloerfelt-Tarp, T. & Kailola, P.J. 1984. Trawled Fishes of Southern Indonesia and Northwest Australia. Jakarta : Dir. Gen. Fish. (Indonesia), German Tech. Coop., Aust. Dev. Ass. Bur. 406 pp.

Hirota, M. & Sasaki, K. 1998. Development of juveniles of four flatheads (Perciformes, Platycephalidae) occurring in southern Japan. Ichthyological Research 45(3): 291-301.

Hutchins, J.B. 2003. Checklist of marine fishes of the Dampier Archipelago, Western Australia. pp. 453-478 in Wells, F.E., Walker, D.I., & Jones, D.S. (eds). Proceedings of the Eleventh International Marine Biological Workshop: The Marine Flora and Fauna of Dampier, Western Australia. Perth : Western Australian Museum.

Imamura, H. 1996. Phylogeny of the family Platycephalidae and related taxa (Pisces: Scorpaeniformes). Species Diversity 1(2): 123-233

Imamura, H. & Nagao, T. 2011. Silurus imberbis Gmelin 1789, a senior synonym of the platycephalid Inegocia japonica (Cuvier 1829), with a proposal to suppress the name. Ichthyological Research 58: 166–169

Imamura, H. & Yoshino, Y. 2009. Authorship and validity of two flatheads, Platycephalus japonicus and Platycephalus crocodilus (Teleostei: Platycephalidae). Ichthyological Research 56: 308-313

Johnson, J.W. 1999. Annotated checklist of the fishes of Moreton Bay, Queensland, Australia. Memoirs of the Queensland Museum 43(2): 709-762.

Johnson, J.W. 2010. Fishes of the Moreton Bay Marine Park and adjacent continental shelf waters, Queensland, Australia. pp. 299-353 in Davie, P.J.F. & Phillips, J.A. Proceedings of the Thirteenth International Marine Biological Workshop, The Marine Fauna and Flora of Moreton Bay. Memoirs of the Queensland Museum 54(3)

Keenan, C.P. 1991. Phylogeny of Australian species of flatheads (Teleostei, Platycephalidae) as determined by allozyme electrophoresis. Journal of Fish Biology 39(Supplement A): 237-249

Knapp, L.W. 1992. Status of type specimens of Platycephalus rodericensis Cuvier, 1829 and P. borboniensis Cuvier, 1829 (Pisces: Platycephalidae). Proceedings of the Biological Society of Washington 105(2): 389-392

Knapp, L.W. 1999. Family Platycephalidae, flatheads, pp. 2385-2421. In: K.E. Carpenter & V.H. Niem (eds). FAO Species Identification Guide for Fishery Purposes. The Living Marine Resources of the Western Central Pacific. Volume 4: Bony Fishes Part 2 (Mugilidae to Carangidae). Food and Agriculture Organization of the United Nations, Rome.

Larson, H.K. & R.S. Williams. 1997. Darwin Harbour fishes: a survey and annotated checklist. In: Hanley, J.R., Caswell, G., Megirian, D. and Larson, H.K. (eds.), Proceedings of the Sixth International Marine Biological Workshop. The Marine Flora and Fauna of Darwin Harbour, Northern Territory, Australia. Museums and Art Galleries, Northern Territory and Australian Scientific Association 1997: 339-380.

Larson, H.K., Williams, R.S. & Hammer, M.P. 2013. An annotated checklist of the fishes of the Northern Territory, Australia. Zootaxa 3696(1): 1-293.

Russell, B.C., Larson, H.K., Hutchins, J.B. & Allen, G.R. 2005. Reef fishes of the Sahul Shelf. The Beagle, Records of the Museums and Art Galleries of the Northern Territory Supplement 1 2005: 83-105

Russell, B.C. & Houston, W. 1989. Offshore fishes of the Arafura Sea. The Beagle, Records of the Museums and Art Galleries of the Northern Territory 6(1): 69-84

Sainsbury, K.J., Kailola, P.J. & Leyland, G.C. (1985) Continental Shelf Fishes of Northern and North-Western Australia. Canberra, C.S.I.R.O. Division of Fisheries Research, 375 pp. (as Suggrundus isacanthus)

Shinomiya, A., Yamada, M. & Sunobe, T. 2003. Mating system and protandrous sex change in the lizard flathead, Inegocia japonica (Platycephalidae). Ichthyol. Res. 50: 383–386.

Whitley, G.P. 1933. Studies in Ichthyology No. 7. Records of the Australian Museum 19(1): 60-112 figs 1-4 pls 11-15 (as Levanaora isacanthus)