Platycephalus marmoratus Stead, 1908

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 : 171-173

Platycephalus marmoratus Stead, 1908

Common English name: Marbled flathead ( Figs. 13–14 ; Table 5)

Platycephalus marmoratus Stead, 1908: 9 , pls. 3–5 (type locality: Port Stephens, NSW, Australia); McCulloch 1929: 402; Coleman, 1980: 109, unnumbered fig.; Hutchins & Thompson 1983: 78, fig. 112 (in part); Hutchins & Swainston 1986: 127, fig. 204 (in part); Paxton & Hanley, 1989: 469 (in part); Knapp, 1991: 29, tab. 3 (in part); Kuiter 1993: 104, two unnumbered figs. (in part); Hutchins 2001: 28; Grant 2004: 196, pl. 89, unnumbered pl.; Hoese et al., 2006: 942 (in part); Imamura, 2006: 296, figs. 1–6.

Planiprora marmorata: Whitley, 1964: 57 .

Material examined. Holotype: AMS I. 15260, 310 mm SL, Port Stephens, NSW, Australia, June 1904.

Other specimens (18 specimens, 152–472 mm SL, from southeastern Australia): 7 specimens listed in Imamura (2006) plus 11 additional specimens: AMS I.18756-001, 331 mm SL, NSW (33°38’S, 151°27’E), 56–59 m depth, 7 Apr. 1975; AMS I.21570-001, 292 mm SL, east of Bulli, NSW (34°20’S, 150°55’E), Feb. 1980; AMS I.26271-012, 362 mm SL, northeast of Sandon Bluffs, NSW (29°39’S, 153°23’E), 36–43 m depth, 10 Oct. 1985; AMS I.43814-005, 228 mm SL, Newcastle, NSW (32°51’S, 151°53’E), 26 May 1993; CSIRO H3985-01, 354 mm SL, south of Newcastle, NSW (33°111’S, 151°43’E), 57 m depth, 29 March 1995; CSIRO H6836-06, 262 mm SL, H6836-07, 298 mm SL, east of Terrigal, NSW (32°25’S, 151°32’E – 33°23’S, 151°35’E), 48–55 m depth, 13 May 2006; NMV A 11848 , 335 mm SL, off Bermagui, NSW (36°26’S, 150°05’E), Apr. 1992; QM I.17021, 2 of 3 specimens, 193–222 mm SL, 7 mile north-northwest of Cape Moreton, Moreton Island, Qld (26°55’S, 153°25’E), 109.7 m depth, 27 Feb. 1975; QM I. 2842, 399 mm SL, Caloundra Bank, Qld (26°48’S, 153°12’E).

Diagnosis. A species of Platycephalus with the following combination of characters: second dorsal- and analfin rays 13; pored lateral-line scales 63–70, all lacking spines; gill rakers 2 + 7–11 = 9–13; snout and interorbit naked; interopercular flap absent; margin of interopercle smooth; upper jaw without large caniniform teeth; fleshy sensory tubes from suborbitals and preopercle slightly developed, partially covering dorsal and ventral margins of cheek region; body and head marbled with dark brown, brown and pale irregular bands and spots; caudal fin blackish with pale posterior margin.

Holotype Non-types

AMS I.15260 n = 18 SL (mm) 310 151–472 Counts:

D 1 I + VII + 0 I + VI–VIII + 0–I

(often I + VII + 0) D 2 13 13 A 13 13 P1 2 + 12 + 7 = 21 1–2 + 11–16 + 5–8 = 19–22 Description. A full description was given by Imamura (2006), which examined only specimens from southeastern Australia (thus specimens of P. orbitals , known from western Australia and previously confused with P. marmoratus , are not included). Counts and measurements are shown in Table 5.

Distribution. Known only from eastern Australia, from off Caloundra Bank, Qld (26°48’S) to Flinders Island, Tas (40°01’S), including NSW and Vic, on sand near low rocky reefs or on rubble in coastal bays to deep offshore reefs in depths from 20 to 80 m (e.g., Paxton & Hanley, 1989; Kuiter, 1993; Hoese et al., 2008; this study).

Size. Maximum length 56 cm ( Grant, 2004). The largest specimen examined during the present study was 472 mm SL (550 mm TL).

Remarks. Platycephalus marmoratus had been confused with a second species, known only from western Australia, until the latter was described (as Platycephalus orbitalis ) by Imamura & Knapp (2009). The former closely resembles P. orbitalis in having 13 second dorsal- and anal-fin rays, 63–70 pored lateral-line scales (65–68 in P. orbitalis ), the snout and interorbit naked, interopercular flap absent, fleshy sensory tubes from the infraorbitals and preopercle covering the cheek region, and the caudal fin blackish with a pale posterior margin. However, it is separable from P. orbitalis in having a smooth interopercle margin (scalloped in P. orbitalis ), fleshy sensory tubes slightly developed, partly covering the dorsal and ventral margins of the cheek region (vs. tubes well developed, mostly covering cheek region, except anteroventrally) and the body and head marbled with dark brown, brown, and pale irregular bands and spots (vs. body and head lacking large distinct spots and bands dorsally). Although overlapping, some head proportions also aid the distinction of P. marmoratus from P. orbitalis , viz. smaller orbit and broader interorbit (orbital diameter 15.2–20.1% HL and interorbital width 13.6–21.4% HL in P. marmoratus vs. 17.5–20.3% HL and 11.9–14.6% HL in P. orbitalis ) (see Imamura & Knapp, 2009: fig. 4). Gill raker numbers (9–13 in total in P. marmoratus vs. 8–10 in P. orbitalis ) may help distinguish between the species.

Figures

FIGURE 13. (A) Dorsal and (B) lateral views of Platycephalus marmoratus, 354 mm SL, south of Newcastle, NSW.

FIGURE 14. Dorsal view of holotype of Platycephalus marmoratus, AMS I. 15260, 310 mm SL, Port Stephens, NSW.