Platycephalus orbitalis Imamura & Knapp, 2009

Imamura, Hisashi, 2015, Taxonomic revision of the flathead fish genus Platycephalus Bloch, 1785 (Teleostei: Platycephalidae) from Australia, with description of a new species, Zootaxa 3904 (2), pp. 151-207 : 173-174

Platycephalus orbitalis Imamura & Knapp, 2009

Common English name: Western-Australian flathead ( Fig. 15 )

Platycephalus orbitalis Imamura & Knapp, 2009: 58 , figs. 1–5 (type locality: northwest of Rottnest Island, WA, Australia). Platycephalus marmoratus (not Stead, 1908): Hutchins & Thompson, 1983: 78, fig. 112; Hutchins & Swainston, 1986: 127, fig. 204 (in part); Paxton & Hanley, 1989: 469 (in part); Knapp, 1991: 29, tab. 3 (in part); Hutchins, 2001: 28; Hoese et al., 2006: 943 (in part).

Material examined. Holotype: CSIRO H 6349-04, 267 mm SL, northwest of Rottnest Island, WA, Australia (31°52.56’S, 115°18.30’E – 31°52.60’S, 115°18.49’E), 100–102 m depth, 10 Apr. 2006.

Paratypes: 6 specimens, 236–333 mm SL, from western Australia, listed in Imamura & Knapp (2009). Other specimen (1 specimen, 337 mm SL, from northwestern Australia): WAM P.27606-001, 337 mm SL, WA (32°03’S, 115°44’E), 28 March 1982.

Diagnosis. A species of Platycephalus with the following combination of characters: dorsal- and anal-fin rays 13; pored lateral-line scales 65–68, all lacking spines; gill rakers 2 + 6–7 = 8–10; snout and interorbit naked; interopercular flap absent; margin of interopercle scalloped; upper jaw without large caniniform teeth; fleshy sensory tubes from infraorbitals and preopercle well developed, covering cheek region, except anteroventrally; head and body lacking distinct large spots and bands dorsally; caudal fin blackish with a pale posterior margin.

Description. A full description was given by Imamura & Knapp (2009).

Distribution. Known only from western Australian waters, from Cape Leeuwin (34°S) north to Cape Cuvier (24°S) (e.g., Hutchins, 2001; Imamura & Knapp, 2009; this study).

Size. Known maximum length 337 mm SL (400 mm TL) ( Imamura & Knapp, 2009; this study).

Remarks. Although Imamura & Knapp (2009) described the holotype as having 2 + 4 = 6 gill rakers, reexamination has confirmed the number as 2 + 6 = 8. The present species is mostly similar to P. marmoratus (see Remarks for P. marmoratus ).

Figures

FIGURE 15. (A) Dorsal and (B) lateral views of Platycephalus orbitalis, CSIRO H 6349 - 04, holotype, 267 mm SL, northwest of Rottnest Island, WA.