Mongrel Tiger Flathead

description

Description. Counts and measurements shown in Table 7. Data for all specimens presented first, followed by holotype condition in parentheses. SL (mm) 279 211 – 322 121 – 489 Counts: Snout, area anteroventral to eye, anterior one-fourth to entire area of interorbit (anterior half) and lower half of suborbital region naked; occipital region scaled. Interorbit narrower than orbital diameter. Upper iris lappet simple, moderately long; lower weakly convex, or absent (absent). Nasal, preorbital and supplemental preopercular spines absent. One suborbital spine present below posterior margin of eye in smallest 121 mm SL specimen, absent in others. Lower preopercular spine longer than upper, not reaching opercular margin. Interopercular flap absent; margin of interopercle smooth. Maxilla extending beyond anterior margin of pupil; some specimens with maxilla reaching to middle of eye (slightly beyond anterior margin of pupil in holotype). Anteromedial portion of upper jaw with one to three (one) large caniniform teeth. Palatine teeth in two rows, villiform or small conical (small conical) in outer row, small to large caniniform (moderately caniniform) in inner row. Vomerine teeth in a single

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 75 – 90; gill rakers 1 – 2 + 6 – 7 = 7 – 9; orbital diameter 16.3 – 22.4 % HL; interorbital width 7.4 – 11.7 % HL; postorbital length 49.1 – 56.9 % HL; suborbital width 6.7 – 9.0 % HL; occipital region scaled; lower half of suborbital region naked; margin of interopercle smooth; one to three large caniniform teeth anteromedially on upper jaw; all or most pored lateral-line scales with one pair of sensory ducts and exterior openings posteriorly; fleshy sensory tubes from suborbitals and preopercle not covering cheek region; swimbladder absent; abdominal cavity pale, slightly silvery.

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

discussion

Remarks. Platycephalus aurimaculatus is most similar to P. conatus and P. richardsoni in having usually 14 anal-fin rays, 12 or 13 caudal-fin rays, the occipital region scaled, the margin of the interopercle smooth and large caniniform teeth anteromedially on the upper jaw, the combination of such characters not occurring in other species of Platycephalus. The present species is easily distinguished from P. conatus and P. richardsoni in lacking a swimbladder (vs. present), and having the lower half of the suborbital region naked (vs. scaled, but scales not developed in 165 mm SL or smaller specimens of P. richardsoni) and the abdominal cavity pale and slightly silvery (vs. dark brown or black). Postorbital length and suborbital width at any given length may also help to separate P. aurimaculatus and P. conatus (postorbital length 49.1 – 56.9 % HL and suborbital width 6.7 – 9.0 % HL in the former vs. 49.7 – 56.2 % HL and 5.4 – 9.7 % HL, respectively, in the latter), although broad overlaps occur in both proportions (Fig. 21). Platycephalus aurimaculatus is distinguishable from P. richardsoni in having 75 – 90 pored lateral-line scales (vs. 65 – 74), 7 – 9 total gill rakers (vs. 12 –

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

distribution

Distribution. Known only from southern Australia, from to Disaster Bay, NSW (149 ° 59 ’ E) to Capel, WA (115 ° 21 ’ E), including Vic, Tas and SA, in bays and coastal waters in depths from 10 to 160 m (e. g., Knapp, 1987; Hoese et al., 2006; Gomon, 2008; this study). Size. Previously reported maximum length 55 cm SL (Gomon, 2008). One specimen examined during the present study measured 489 mm SL (565 mm TL).

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