Platycephalus caeruleopunctatus McCulloch, 1922

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 : 164-166

Platycephalus caeruleopunctatus McCulloch, 1922

Common English name: Bluespotted flathead ( Figs. 8–9 ; Table 3)

Platycephalus caeruleopunctatus McCulloch, 1922: 120 (type locality: Port Jackson, NSW, Australia); McCulloch, 1929: 400; Coleman, 1980: 113, unnumbered color fig.; Hutchins & Swainston, 1986: 127, fig. 201; May & Maxwell, 1986: 275, unnumbered fig.; Paxton & Hanley, 1989: 468; Knapp, 1991: 29, tab. 3; Kuiter 1993: 103, unnumbered fig.; Grant, 2004: 196; Hoese et al., 2006: 940; Imamura, 2006: 304, tab. 1.

Trudis caeruleopunctatus: Whitley, 1931b: 158 ; Whitley, 1964: 57.

Material examined. Lectotype: AMS I. 3163, 291 mm SL, Port Jackson, NSW, Australia, designated by Whitley (1931b).

Other specimens (20 specimens, 73.0– 504 mm SL, from southeastern Australia): AMS I. 3947, 266 mm SL, off Barrenjoey, NSW (33°35’S, 151°21’E), 46–51 m depth, 22 Feb. 1898; AMS I. 9567, 206 mm SL, near Sydney, NSW (33°50’S, 151°20’E). 1908; AMS I. 10329, 193 mm SL, off Murray River mouth, SA (35°00’S, 138°00’E), 37 m depth, 17 Aug. 1909; AMS I. 10655, 278 mm SL, Lord Howe Island, NSW (31°31’S, 159°05’E), 1910; AMS I. 14928, 242 mm SL, Bellinger River, NSW (30°27’S, 152°54’E), 10 Nov. 1913; AMS I. 15202, 217 mm SL, Lake Macquarie, NSW (33°02’S, 151°36’E), 18 Nov. 1913; AMS I.19832-002, 338 mm SL, 6 km off Whale Beach, Sydney, NSW (33°39’S, 151°23’E), 55 m depth, 10 Oct. 1976; AMS I.19893-013, 2 specimens, 73.0– 95.1 mm SL, north end of Black Point, south of Nadgee River mouth, NSW (37°30’S, 149°58’E), 5 m depth, 26 Aug. 1976; AMS I.20721-001, 275 mm SL, Coffs Harbour, NSW (30°18’S, 153°08’E), 13 Aug. 1978; AMS I.20723-001, 127 mm SL, Red Rock, NSW (29°59’S, 153°14’E), 11 Mar. 1978; AMS I.37964-001, 111 mm SL, Hordern’s Bay, Port Hacking, NSW (34°05’S, 151°09’E), 10 Aug. 1999; AMS I.39988-003, 133 mm SL, Sydney Harbour, NSW (33°51’S, 151°15’E), 2 Sep. 1999; AMS I.44633-022, 87.5 mm SL, Mimosa Rocks National Park, Moon Bay, NSW (36°41’44”S, 149°59’23”E), 3–5 m depth, 10 Apr. 2008; AMS IA. 5700, 166 mm SL, Maroubra, Sydney, NSW (33°51’S, 151°16’E), 1933; AMS IB. 6292, 142 mm SL, off Ballina, NSW (28°S, 153°E), 1962; CSIRO H4494-01, 504 mm SL, Lakes Entrance, Vic (37°55’S, 148°01’E), 5 March 1997; NMV A 2903, 419 mm SL, 40 km south of Lakes Entrance, Vic (38°10’S, 148°E), 53 m depth; NMV A 2908, 460 mm SL, 29 km south-southeast of Lakes Entrance, Vic (38°S, 147°59’E), 53 m depth; QM I. 22310, 330 mm SL, Lakes Entrance, Vic (37.53°S, 148°E), 14 Aug. 1985.

Diagnosis. A species of Platycephalus with the following combination of characters: second dorsal- and analfin rays usually 14; gill rakers 4–6 + 13–15 = 19–21; interorbital width 5.9–16.6% HL; suborbital width 7.6–11.8% HL; a finger-like interopercular flap present; upper jaw without large caniniform teeth; caudal fin with three to six dark brown to black bars and/or spots posteriorly.

Description. Counts and measurements shown in Table 3. Data for all specimens presented first, followed by lectotype condition in parentheses.

Snout, area anteroventral to eye, interorbit and occipital region scaled; lower half of suborbital region naked. Snout shorter than orbital diameter in 88 mm SL or smaller specimens, longer in larger specimens (including lectotype). Interorbit narrower than orbital diameter in 419 mm SL or smaller specimens, wider in larger specimens (including lectotype). Upper iris lappet simple, triangular; lower simple, weakly convex. Nasal spine usually absent (including lectotype), rarely one spine present in one specimen (323 mm SL). One suborbital spine usually present below posterior margin of eye in 242 mm SL or smaller specimens, absent in larger specimens (including lectotype); one additional suborbital spine present below and slightly anterior to middle of eye in 133 mm and 166 mm SL specimens. Lower preopercular spine about equal in length to upper spine in smallest (73.0 mm SL) specimen, or slightly longer than upper but not reaching opercular margin in larger specimens (including lectotype). A supplemental preopercular spine present in some specimens, 278 mm SL or smaller, absent in larger specimens (including lectotype). Finger-like interopercular flap present; margin of interopercle smooth. Maxilla reaching to or just beyond anterior margin of pupil, but not to middle of eye (beyond anterior margin of pupil). Anterior portion of upper jaw with some large conical or small caniniform (small caniniform) teeth medially. Palatine teeth irregularly arranged in one (rarely, in 87.5 mm SL specimen), or more usually two to four (ca. four) rows. Vomerine teeth irregularly arranged in one or two (one) rows anteriorly, two to five (three) posteriorly, becoming larger posteriorly; posterior row number tending to increase with growth. Fleshy sensory tubes from suborbitals not covering cheek region; those from preopercle not covering cheek region in 142 mm SL or smaller specimens; not covering it or slightly developed and partially covering its ventral margin in larger specimens (not covering cheek region). Posterior tip of pelvic fin not quite reaching anal-fin origin, or reaching up to base of fourth anal-fin ray (not reaching anal-fin origin). Posterior margin of caudal fin tending to change with growth; slightly rounded or mostly straight by 166 mm SL, mostly straight or slightly concave by 338 mm SL, and slightly concave in larger specimens (mostly straight).

Lectotype Non-types AMS I.3163 n = 20 SL (mm) 291 73.0–504 Counts:

Color in alcohol. Color of lectotype mostly faded, retaining brownish spots approximating bands on pectoral fin and six black bars on posterior portion of caudal fin ( Fig. 9 ). In other specimens ( Fig. 8 ), ground color of head and body pale brown above, paler below. Dorsal surface of body with several indistinct brown or distinct dark brown bands, and/or scattered small brownish spots; scattered small pale spots present dorsally in 461 mm SL specimen. Side of body sometimes with dark brown, gray, or purplish gray band. First and second dorsal fins with pale brownish elliptical spots along rays. Pectoral fin with several pale brown bands, with small pale brown spots tending to form bands, or with large brown spots not forming bands; lower margin of pectoral fin pale. Pelvic fin pale brown or brown, with or without indistinct spots; outer margin of pelvic fin paler. Anal fin pale or with melanophores on posterior two rays, or somewhat dusky in some larger specimens. Caudal fin with three to six dark brown to black bars and/or spots posteriorly, tending to become longer ventrally; other caudal fin regions with several pale brown to brown spots.

Distribution. Known from southeastern Australia, from off Calliope River, Qld (24°01’S) to outside Murray River mouth, SA (138°E), occurring in coastal bays and estuaries to offshore sand flats in depths from 5 to 100 m (e.g., Last et al., 1983; Kuiter, 1993; Hoese et al., 2006; this study).

Size. Maximum length recorded 68 cm ( Hutchins & Swainston, 1986). The largest specimen examined during the present study was 504 mm SL (573 mm TL) ( Fig. 8 ).

Remarks. Platycephalus caeruleopunctatus bears most similarities to P. speculator in having usually 14 second dorsal- and anal-fin rays, a finger-like interopercular flap, and the caudal fin with three to six dark brown to black bars and/or spots posteriorly (two to four black spots irregularly positioned posteroventrally in 155 mm SL or smaller specimens, or with three or four black spots serially arranged posteroventrally along caudal fin margin in larger specimens in P. speculator ). This combination of characters was not apparent in other species of Platycephalus . However, P. caeruleopunctatus has 19–21 gill rakers in total (11–14 in P. speculator ), plus a broader interorbit (width 5.9–16.6% HL in vs. 5.8–14.6% HL in P. speculator ) and suborbital region (suborbital width 7.6–11.8% HL vs. 6.1–10.0% HL), which largely separates the two species ( Fig. 10 ).

Figures

FIGURE 8. (A) Dorsal and (B) lateral views of Platycephalus caeruleopunctatus, CSIRO H 4494 - 01, 504 mm SL, Lakes Entrance, Vic.

FIGURE 9. Dorsal view of lectotype of Platycephalus caeruleopunctatus, AMS I. 3163, 291 mm SL, Port Jackson, NSW.

FIGURE 10. Comparison of (A) interorbital width and (B) suborbital width versus standard length in Platycephalus caeruleopunctatus (solid circles) and P. speculator (open circles). H, holotype; L, lectotype.