Deep Water Flathead

description

Description. Counts and measurements shown in Table 8. Snout, interorbit, and occipital and lower half of suborbital regions scaled; area anteroventral to eye naked. Interorbit narrower than orbital diameter. Upper iris lappet simple, weakly pointed; lower absent. Nasal, preorbital and supplemental preopercular spines absent. One suborbital spine present below and slightly posterior to posterior margin of eye in 337 mm SL or smaller specimens, absent in larger specimens; one additional spine also present below middle of eye on right side of 191 mm SL specimen. Lower preopercular spine longer than upper, not reaching opercular margin; some specimens with lower spine more than twice length of upper. Interopercular flap absent; margin of interopercle smooth. Maxilla not usually reaching anterior margin of pupil or beyond, although it may reach to middle of eye in some specimens. Upper jaw with one or two large caniniform teeth anteromedially. Palatine teeth in two rows, villiform or small conical in outer row, large conical to large caniniform in inner row. Vomerine teeth in one or two rows. Fleshy sensory tubes from suborbitals and preopercle not covering cheek region. Posterior tip

Taxonomic revision of the flathead fish genus Platycephalus Bloch, 1785 (Teleostei: Platycephalidae) from Australia, with description of a new species

diagnosis

Diagnosis. A species of Platycephalus with the following combination of characters: second dorsal- and analfin rays usually 14; caudal-fin rays 12 – 13; pored lateral-line scales 70 – 81; gill rakers 1 – 2 + 6 – 9 = 7 – 11; orbital diameter 16.9 – 22.6 % HL; interorbital width 7.4 – 14.1 % HL; postorbital length 49.7 – 56.2 % HL; suborbital width 5.4 – 9.7 % HL; occipital and lower half of suborbital regions scaled; margin of interopercle smooth; one or two large caniniform teeth present anteromedially on upper jaw; all or most pored lateral-line scales with one pair of sensory ducts and exterior openings posteriorly; swimbladder present; abdominal cavity dark brown or black.

Taxonomic revision of the flathead fish genus Platycephalus Bloch, 1785 (Teleostei: Platycephalidae) from Australia, with description of a new species

discussion

Remarks. Platycephalus conatus most resembles P. richardsoni in having the lower half of the suborbital region scaled, a swimbladder present and the abdominal cavity dark brown or black; this combination of characters does not occur in other species of Platycephalus. Platycephalus conatus can be separated from P. richardsoni in having 7 – 11 total gill rakers (vs. 12 – 17 in P. richardsoni), and all or most pored lateral-line scales with one pair of sensory ducts and exterior openings posteriorly (vs. usually two pairs of sensory ducts and exterior openings).

Taxonomic revision of the flathead fish genus Platycephalus Bloch, 1785 (Teleostei: Platycephalidae) from Australia, with description of a new species

distribution

Distribution. Known from southern Australia, from Lakes Entrance, Vic (147 ° 59 ’ E) to Geraldton, WA (ca. 29 ° 21 ’ S), including SA, on continental shelf and upper slopes in depths from 53 to 530 m (e. g., May & Maxwell, 1986; Hoese et al., 2006; Gomon, 2008; this study). Size. Maximum length 70 cm SL (Gomon, 2008). The largest specimen examined during the present study was 607 mm SL (701 mm TL).

Taxonomic revision of the flathead fish genus Platycephalus Bloch, 1785 (Teleostei: Platycephalidae) from Australia, with description of a new species