Platycephalus fuscus Cuvier

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 : 186-190

Platycephalus fuscus Cuvier in Cuvier & Valenciennes, 1829

Common English name: Dusky flathead

( Figs. 25–26 ; Table 10)

Platycephalus fuscus Cuvier in Cuvier & Valenciennes, 1829: 241 (type locality: Port Jackson, NSW, Australia); Quoy & Gaimard, 1834: 681, fig. 1; Castelnau, 1872: 86; McCulloch, 1929: 400; Coleman, 1980: 110, unnumbered color fig.; Scott et al., 1980: 167, unnumbered fig.; Hutchins & Swainston, 1986: 127, fig. 196; Paxton & Hanley, 1989: 468; Knapp, 1991: 29, tab. 3; Kuiter 1993: 104, two unnumbered figs.; Kuiter, 1994: 522, fig. 464; Grant, 2004: 189, pl. 86; Hoese et al., 2006: 941; Imamura, 2006: 305, tab. 1; Gomon, 2008: 519, unnumbered fig.

Platycephalus cinereus Günther, 1872: 661 (type locality: South Australia).

Platycephalus mortoni Macleay, 1883: 206 (type locality: lower Burdekin River, Qld, Australia); McCulloch, 1929: 401.

Planiprora fusca: Whitley, 1931a: 237 ; Whitley, 1964: 57.

Planiprora cinerea: Whitley, 1964: 57 .

Material examined. Holotype: MNHN 6867, 346 mm SL, Port Jackson, NSW, Australia.

Other specimens (21 specimens, 102–750 mm SL, from eastern Australia): AMS I.6741-001, 241 mm SL, Lane Cove River, NSW (33°50’S, 151°11’E), 5 Sep. 1972; AMS I.17178-010, 2 specimens, 252–317 mm SL, Sydney Harbour, NSW (33°50’S, 151°16’E), 13 Aug. 1972; AMS I.21149-032, 212 mm SL, Bohle River estuary, Townsville, Qld (19°13’S, 146°48’E), 8 Oct. 1965; AMS I.22474-001, 120 mm SL, Tuross estuary, Reedy Island, NSW (36°05’S, 150°07’E), 1981; AMS I.30344-001, 210 mm SL (dissected by Imamura, 1996), Apple Tree Bay, Ku-ring-gai Chase National Park, NSW (33°39’S, 151°01’E), 1 Oct. 1974; AMS I.34342-001, 292 mm SL, northeast end of West Flat, Port Clinton, Qld (22°33.28’S, 150°45.05’E), 0–1 m depth, 25 Sep. 1993; AMS I.36105-001, 183 mm SL, Botany Bay, NSW (33°59’S, 151°09’E), 0–5 m depth, 9 Apr. 1992; AMS I.41262-024, 218 mm SL, Lennox Head Beach, NSW (28°48.11’S, 153°35.83’E), 0–1 m depth, 19 Mar. 2002; AMS I.41264- 0 20, 2 of 5 specimens, 164–189 mm SL, north side of Prospect Bridge, North Creek, NSW (28°50.87’S, 153°34.28’E), 0–0.5 m depth, 19 Mar. 2002; AMS I.41287-020, 186 mm SL, Yamba, NSW (38°03’S, 147°50’E), 0–0.5 m depth, 11 Dec. 2002; AMS I.41874-011, 204 mm SL, Hastings Point, just inside mouth of Cudgen Creek, NSW (28°21.68’S, 153°34.53’E), 0–1.5 m depth, 11 Dec. 2002; AMS IB. 8204, 579 mm SL, Eden, NSW (37°04’S, 149°55’E), 9 June 1968; BMNH 1870.12.27.25, holotype of Platycephalus cinereus Günther, 1872 , 330 mm SL, South Australia; CSIRO CA 126, 277 mm SL, fish market, Brisbane, Qld, 6 June 1977; CSIRO H3986-01, 410 mm SL, east of Newcastle, NSW (32°54’S, 152°00’E), 79 m depth, 29 Mar. 1995; NMV A 1688, 750 mm SL, Snowy River mouth, Mario, Vic (37°48’S, 148°32’E), 27 Nov. 1980; NMV A25513 -001, 457 mm SL, Gippsland Lakes, Vic (37°59’S, 147°43’E), 20 Nov. 2003; QM I. 16513, 373 mm SL, Murray River mouth, north of Cardwell, Qld (18°05’S, 146°02’E), date unknown; QM I. 20085, 102 mm SL, Russell River mouth, Qld (17°14’S, 145°58’E), Nov. 1982.

Diagnosis. A species of Platycephalus with the following combination of characters: first dorsal fin usually with two small isolated spines anteriorly; second dorsal- and anal-fin rays usually 13; interorbital width 8.2–17.1% HL; postorbital length 6.5–10.0% HL; a finger-like interopercular flap present; upper jaw without large caniniform teeth; teeth absent on dorsal surface of anterolateral edge of upper jaw; palatine teeth in two rows; vomerine teeth in one row anteriorly, two to three posteriorly; in larger specimens, caudal fin brownish, usually with a single black spot near upper posterior margin, upper half of fin to margin with or without small pale brown, brown or black spots.

Description. Counts and measurements shown in Table 10. Data for all specimens presented first, followed by holotype condition in parentheses.

Snout, area anteroventral to eye, interorbit and occipital region scaled; lower half of suborbital region naked. Interorbit narrower than orbital diameter in 346 mm SL (holotype) or smaller specimens, equal to or wider in larger specimens. Upper iris lappet simple, triangular; lower simple, weakly convex. Nasal spine present in smallest 102 mm SL specimen, absent in larger specimens. Preorbital spine absent. One suborbital spine present below eye or absent in 330 mm SL or smaller specimens, absent in larger specimens (including holotype). Lower preopercular spine slightly longer than upper, not reaching opercular margin. Supplemental preopercular spine present or absent (absent); often present in smaller specimens. Finger-like interopercular flap present; margin of interopercle smooth. Maxilla reaching from anterior to near posterior margins of pupil (middle of eye) [slightly beyond posterior margin of eye in largest (750 mm SL) specimen]. Upper jaw with some moderate or large conical, or small or moderate caniniform (small caniniform) teeth anteromedially. Palatine teeth in two rows, villiform in outer row, moderately conical in inner row. Vomerine teeth villiform, in one row anteriorly, two or three (two) posteriorly, tending to become larger posteriorly; posterior row number tending to increase with growth. Fleshy sensory tubes from suborbitals and preopercle not covering cheek region. Posterior tip of pelvic fin reaching from anus to base of third anal-fin ray (base of second anal-fin ray). Posterior margin of caudal fin slightly concave or mostly straight (mostly straight).

Color in alcohol. Color of holotype mostly faded, retaining only one brownish marking on posterior portion of caudal fin ( Fig. 26 A). In other specimens ( Fig. 25 ), ground color of head and body pale to dark brown above, paler below. Dorsal surface of head and body with small darker spots; two darker bands below second dorsal fin. Side of body with or without gray or brown spots or bands. First and second dorsal, pectoral and pelvic fins with small pale brown or brown spots. Anal fin pale or with melanophores along rays. In 120 mm SL or larger specimens, caudal fin brownish, usually with single black spot near upper posterior margin; upper half of fin to margin otherwise with or without small pale brown, brown, or black spots. Smallest (102 mm SL) specimen with three distinct blackish bands on posterior portion of caudal fin. Posterior and ventral margins of caudal fin paler. Largest (750 mm SL) specimen with many small dark brown spots on entire caudal fin.

Distribution. Known from eastern Australia, fromRussell River mouth, Qld (17°14’S) to Port Phillip Bay, Vic (ca. 38°59’S, 145°E), including NSW, on shallow sand and mud substrate to 75 m depth, preferring bays, estuaries and quiet inlets (e.g., Kuiter, 1993; Hoese et al., 2006; Gomon, 2008; this study).

Size. Maximum length 1.2 m (e.g., Kuiter, 1993; Gomon, 2008). The largest specimen examined during the present study was 750 mm SL (874 mm TL).

Remarks. Platycephalus fuscus is similar to P. endrachtensis , P. w e s t r al i a e, P. angustus , P. australis , P. cultellatus , P. indicus and two undescribed species ( Platycephalus sp. 1 and sp. 2 sensu Nakabo, 2002) in having usually 13 second dorsal- and anal-fin rays, the snout, area anteroventral to eye, interorbit and occipital region scaled, large caniniform teeth absent anteromedially on the upper jaw, a finger-like interopercular flap and palatine teeth in two rows. Although P. f us cus mostly resembles P. angustus and P. cultellatus in having the first dorsal fin usually with two small isolated spines anteriorly (one in other Australian species), it can be distinguished from them by the narrower interorbit and shorter postorbital region (interorbital width 8.2–17.1% HL and postorbital length 6.5–10.0% HL in P. fuscus vs. 7.3–17.3% HL and 55.5–67.8% HL in P. angustus , and 6.5–19.0% HL and 51.8–66.8% HL in P. cultellatus ) ( Fig. 26 ). Platycephalus fuscus also differs from P. angustus in lacking teeth on the dorsal surface of the anterolateral edge of the upper jaw (teeth present in P. angustus specimens ca. 76 mm SL or longer) and having vomerine teeth in one row anteriorly, two to three posteriorly (number of vomerine tooth rows tending to increase with growth (from two to four rows in 106–184 mm SL specimens and a single broad band of teeth in larger specimens). Caudal fin coloration clearly distinguishes P. f us cus from the above eight species (except for the smallest specimen examined).

See Imamura (2013a) for a detailed discussion of the synonymy of P. f us c u s and Platycephalus mortoni Macleay, 1883 , originally described from a single specimen from lower Burdekin River, Qld, Australia.

Paxton & Hanley (1989) and Hoese et al. (2006) regarded P. f u s c u s as a senior synonym of Platycephalus cinereus Günther, 1872 ( Fig. 26 B), but gave no reasons. This synonymy was reconfirmed here.

Figures

FIGURE 25. (A) Dorsal and (B) lateral views of Platycephalus fuscus, AMS I. 41264 - 020, 189 mm SL, north side of Prospect Bridge, North Creek, NSW.

FIGURE 26. Dorsal views of holotypes of (A) Platycephalus fuscus, MNHN 6867, 346 mm SL, Port Jackson, NSW and (B) P. cinereus, BMNH 1870.12. 27.25, 330 mm SL, SA.