Platycephalus endrachtensis Quoy and Gaimard, 1825

Common English name: Northern sand flathead (Figs. 28–29; Table 11)

Platycephalus endrachtensis Quoy & Gaimard, 1825: 353 (type locality: Shark Bay, WA, Australia); Cuvier in Cuvier & Valenciennes, 1829: 240; Imamura, 2008: 405, figs. 1b, 2–3, 6b.

Platycephalus arenarius Ramsay & Ogilby, 1886: 577 (type locality: Middle Harbor, Port Jackson, NSW, Australia); McCulloch, 1929: 401; Gloerfelt-Tarp & Kailola, 1984: 113, unnumbered fig.; Hutchins & Swainston, 1986: 127, fig. 202; Allen & Swainston, 1988: 52, fig. 277; Paxton & Hanley, 1989: 467; Knapp, 1991: 29, tab. 3; Kuiter, 1993: 102, unnumbered fig.; Allen, 1997: 80, pl. 21-16; Knapp, 1999: 2407, unnumbered fig.; Grant, 2004: 194, pl. 88; Hoese et al., 2006: 939; Imamura, 2006: 304, tab. 1.

Trudis arenarius: Whitley, 1964: 57.

Material examined. Lectotype: MNHN 6865, 175 mm SL (snout damaged, measured by Blanc & Hureau, 1968), Shark Bay, WA, Australia, designated by Imamura (2008).

Paralectotype: MNHN 2007-0128 (ex. MNHN 6865), 153 mm SL (snout damaged, measured by Blanc & Hureau, 1968), collected with lectotype.

Other specimens (21 specimens, 97.2–330 mm SL, from): 12 specimens, including AMS B.7136, holotype of Platycephalus arenarius Ramsay & Ogilby, 1886, were listed in Imamura (2008); 8 additional specimens: AMS E.1581, 1 of 6 specimens, 286 mm SL, 35 km SE of Double Island Point, Qld (about 26°10’S, 153°20’E), 29 June 1910; CSIRO 5974-14, 330 mm SL, Jimbaran Bay, Bali, Indonesia (08°45’S, 115°10’E), from Kedonganan fish market, 5 Oct. 2002; CSIRO A 1424, 113.9 mm SL, Port Gregory, WA (28°12’S, 114°15’E), 25 Aug. 1945; CSIRO CA 2964, 259 mm SL, off Port Headland, WA (20°14’S, 117°45’E), 27.0 m depth, 22 Aug. 1982; NMV A22147, 1 of 2 specimens, 120 mm SL, 2 km E of St. Helens, Tas (41°16’S, 148°22’E), 13 Nov. 1969; NTM S.10733-044, 302 mm SL, Jimbaran fish market, Bali, Indonesia (08°46’S, 115°10’E), 1981; WAM P.32381-009, 177 mm SL, Cape Peron North, WA (25°30.484’0”S, 113°33.688’0”E), 25 Feb. 2003; WAM P.32429-004, 170 mm SL, Cape Bellefin, WA (25°49.939’S, 113°14.274’E), 1 Mar. 2003.

Diagnosis. A species of Platycephalus with the following combination of characters: first dorsal fin with a single small isolated spine anteriorly; second dorsal- and anal-fin rays usually 13; interorbital width 7.7–12.0% HL; postorbital length 50.7–56.9% HL; snout, area anteroventral to the eye, interorbit and occipital region scaled; upper iris lappet simple, triangular; 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 arranged in two rows; usually four or more dark longitudinal bands on caudal fin.

Description. Counts and measurements shown in Table 11. Data for all specimens presented first, followed by lectotype condition in parentheses.

Lectotype Paralectotype Holotype of P. arenarius Non-types

MNHN 6865 MNHN 2007-0128 AMS B.7136 n = 20 SL (mm) 175* 153* 239 97.2–330 Counts:

Snout, area anteroventral to eye, interorbit and occipital region scaled; lower half of suborbital region naked. Interorbit narrower than orbital diameter. Upper iris lappet simple, triangular; lower simple, weakly convex. Nasal and preorbital spines absent. One suborbital spine present below posterior margin of eye in 177 mm SL or smaller specimens (including lectotype), absent in larger specimens. Lower preopercular spine slightly longer than upper, not reaching opercular margin. Supplemental preopercular spine usually present in 207 mm SL or smaller specimens, absent in larger specimens (absent in lectotype). Finger-like interopercular flap present; margin of interopercle smooth. Maxilla reaching from near anterior margin of pupil to middle of eye (upper jaw damaged in lectotype). Upper jaw with moderate or large conical, or small caniniform teeth anteromedially. Palatine teeth in two rows, villiform in outer row, moderate conical in inner. Vomerine teeth sparsely arranged in one or two rows (vomer damaged in lectotype); number of teeth tending to increase with growth. Fleshy sensory tubes from suborbitals and preopercle not covering cheek region. Posterior tip of pelvic fin reaching from just anterior to origin of anal fin, to base of third anal-fin ray (not examined in lectotype). Posterior margin of caudal fin mostly straight, or slightly rounded (slightly rounded).

Color in alcohol. Color of lectotype mostly faded, retaining melanophores only on area between ninth and last anal-fin rays, and four brownish bands on caudal fin (Fig. 29 A). In other specimens (Fig. 28), ground color of head and body pale to dark brown above, paler below. Dorsal surface of head and body with small dark spots. Side of body with or without gray or brown band. First and second dorsal, pectoral and pelvic fins with small pale to dark brown spots. Anal fin with melanophores along rays; area with melanophores tending to become broader with growth, from the 10th to last rays in smallest (97.2 mm SL) specimen, and from second to last rays in largest (330 mm SL) specimen. Caudal fin with three to six (usually four or more; three in faded specimens) dark brown or black longitudinal bands.

Distribution. Known from Australia, from Cliff Point, Qld (ca. 22°32’S) to St. Helens, Tas (41°16’S), and from Hamelin Bay, WA (ca. 34°10’S) to Port Hedland (20°0’S) and Bali, Indonesia, in estuaries and coastal bays on clean sand in depths from 1–60 m (e.g., Hutchins & Swainston, 1986; Kuiter, 1993; Knapp, 1999; Hoese et al., 2006; Imamura, 2008; this study).

Size. Maximum length 45 cm (e.g., Hutchins & Swainston, 1986; Kuiter, 1993). The largest specimen examined during the present study was 330 mm SL (362 mm TL) (Fig. 28).

Remarks. The name Platycephalus endrachtensis had been mistakenly referred to a species having a yellow blotch on the upper portion of the caudal fin when fresh by many authors (e.g., Taylor, 1964; Gloerfelt-Tarp & Kailola, 1984; Sainsbury et al. 1985; Hutchins & Swainston 1986; Knapp, 1999) until Imamura (2008) revealed it to be a senior synonym of P. arenarius Ramsay & Ogilby, 1886 (Fig. 29 B), P. westraliae being the species with a yellow blotch [see Imamura (2008) for a detailed discussion].

Platycephalus endrachtensis most resembles P. angustus, P. australis, P. cultellatus and P. indi cus, P. westraliae, and Platycephalus sp. 1 and sp. 2 (sensu Nakabo, 2002) in having usually 13 second dorsal- and analfin rays, the snout, area anteroventral to the eye, interorbit, and occipital region scaled, large caniniform teeth absent on the upper jaw, a finger-like interopercular flap, palatine teeth arranged in two rows and the caudal fin with dark brown or black longitudinal bands It can be distinguished from P. angustus, P. cultellatus, and Platycephalus sp. 1 and sp. 2 in having the first dorsal fin with a single small isolated spine anteriorly (usually two in the latter four species), and also from P. angustus in lacking teeth on the dorsal surface of the upper jaw (present in P. angustus specimens ca. 76 mm SL or larger) and having vomerine teeth in one or two rows (vs. number of vomerine tooth rows tending to increase with growth, from two to four rows in 106–184 mm SL specimens, respectively, and forming a single broad band of teeth in larger specimens). Platycephalus endrachtensis is also separable from P. westraliae in having a simple triangular upper iris lappet (usually broad and bilobed in P. westraliae) and by lacking a yellow blotch on the caudal fin when fresh (yellow blotch present on upper portion of caudal fin in P. westraliae). Platycephalus endrachtensis differs from the above eight species in having a narrower interorbit and shorter postorbital region (interorbital width 7.7–12.0% HL and postorbital length 50.7–56.9% HL in P. endrachtensis vs. 7.3–17.3% HL and 55.5–67.8% HL in P. angustus, 6.5–18.1% HL and 51.6–63.6% HL in P. australis, 6.5–19.0% HL and 51.8–66.8% HL in P. cultellatus, 7.2–18.4% HL and 51.4–61.6% HL in P. i n di cu s, 6.3–17.0% HL and 51.2–60.9% HL in P. westraliae, 8.2–17.2% HL and 53.9–61.7% HL in Platycephalus sp. 1, and 9.2–17.9% HL and 54.4–63.5% HL in Platycephalus sp. 2) (Fig. 19).

The generally greater number (usually four or more vs. two or three, respectively) of longitudinal bands on the caudal fin may also help to differentiate P. endrachtensis from the other species (except P. australis, P. cultellatus, and Platycephalus sp. 1 and sp. 2).

Knapp (1999) stated that P. endrachtensis (as P. arenarius) was distributed around northern Australia from Jervis Bay, NSW to Hamelin Bay, WA. However, there have been no specimens collected from the area between Cliff Point, Qld (ca. 22°32’S) and Port Hedland, WA (20°0’S) deposited in the major Australian ichthyological collections (i.e., AMS, CSIRO, NMV, NTM, QM and WAM) visited by the present author. Pending the collection of voucher specimens, the above area is omitted from the distribution of P. endrachtensis.