Platycephalus speculator Klunzinger, 1872

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 : 167-170

Platycephalus speculator Klunzinger, 1872

Common English name: Southern bluespotted flathead ( Figs. 11–12 ; Table 4 )

Platycephalus speculator Klunzinger, 1872: 28 (type locality: Hobson’s Bay, Vic, Australia); McCulloch, 1929: 400; Hutchins & Thompson, 1983: 78, fig. 109; Last et al., 1983: 334, fig. 28.22; Hutchins & Swainston, 1986: 127, fig. 200; May & Maxwell, 1986: 277, unnumbered fig.; Paxton & Hanley, 1989: 470; Knapp, 1991: 29, tab. 3; Kuiter 1993: 103, unnumbered fig.; Grant, 2004: 194, unnumbered pl.; Hoese et al., 2006: 943; Imamura, 2006: 305, tab. 1; Gomon, 2008: 521, unnumbered fig.

Platycephalus castelnaui Macleay, 1881: 587 (type locality: King George Sound, WA, Australia); McCulloch, 1929: 401; Coleman, 1980: 115, unnumbered color fig.

Cacumen speculator: Whitley, 1931a: 326 .

Planiprora melsoni Whitley, 1945: 38 (type locality: beach at Geraldton, WA, Australia).

Planiprora castelnaui: Whitley, 1952: 32 ; Whitley, 1964: 57.

Neoplatycephalus speculator: Whitley, 1964: 57 .

Material examined. Holotype: SMNS 1570, 256 mm SL, Hobson's Bay, Vic, Australia.

Other specimens (20 specimens, 117–493 mm SL, from southern Australia): AMS I.16354-001, holotype of Platycephalus castelnaui Macleay, 1881 , 281 mm SL, King George Sound, WA; AMS I.17611-010, 117 mm SL, York Peninsula, SA (35°00’S, 137°44’E), 1 m depth, 23 Dec. 1973; AMS I.17615-010, 144 mm SL, 16 km south of Tumby Bay, SA (34°24’S, 136°08’E), 27 Dec. 1973; AMS I.20180-048, 3 specimens, 152–157 mm SL, Penneshaw, Kangaroo Island, SA (35°44’S, 138°58’E), 3–5 m depth, 9 March 1978; AMS IB.1367, holotype of Planiprora melsoni Whitley, 1945 , 118 mm HL (head only), beach at Geraldton, WA; AMS IB. 2119, 287 mm SL, Port Arlington, Vic (38°07’S, 144°40’E), 1947; AMS IB. 2120, 243 mm SL, Port Arlington, Vic (38°07’S, 144°40’E), 7 Sep. 1947; AMS IB. 7593, 339 mm SL, Port Phillip Bay, Vic (38°09’S, 144°52’E), 1966; CSIRO H4317-02, 451 mm SL, CSIRO H4317-04, 315 mm SL, fish market, from Port Phillip Bay, Vic, March 1997; NMV 29242-001, 232 mm SL, off Wallaroo, Spencer Gulf, SA (33°49’51”S, 137°32’01”E), 22–29 m depth, 7 Oct. 2005; NMV A21467, 2 specimens, 144–179 mm SL, Vic, 13 Nov. 1979; NMV A 3509, 220 mm SL, off Point Ormand, just south of Hobsons Bay, Port Phillip Bay, Vic (37°53’S, 144°59’E), 29 Oct. 1980; NMV A 19854 , 255 mm SL, 3.2 km west of Sandringham, Port Phillip Bay, Vic (37°57’S, 144°57’E), 30 March 1971; WAM P.24537- 0 0 1, 404 mm SL, Mandurah, WA (32°32’S, 115°43’E), 1973; WAM P.25720-001, 493 mm SL, Five Fathom Bank, WA (32°12’S, 115°40’E), Dec. 1976; WAM P.28294-002, 212 mm SL, Lucky Bay, WA (34°00’S, 122°14’E), 12 Apr. 1984.

Diagnosis. A species of Platycephalus with the following combination of characters: second dorsal- and analfin rays usually 14; gill rakers 2–3 + 9–11 = 11–14; interorbital width 5.8–14.6% HL; suborbital width 6.1–10.0% HL; a finger-like interopercular flap present; upper jaw without large caniniform teeth; caudal fin with two to four black spots irregularly positioned posteroventrally in 155 mm SL or smaller specimens, three or four black spots serially arranged posteroventrally along caudal-fin margin in larger specimens.

Description. Counts and measurements shown in Table 4 . 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. Upper iris lappet simple, triangular; lower simple, weakly convex. Nasal spine absent. Preorbital spine usually absent (including holotype), rarely present in some specimens. One suborbital spine usually present below posterior margin of eye in 221 mm SL or smaller specimens, absent in larger specimens (including holotype); one additional suborbital spine present below and slightly anterior to middle of eye in 144 mm SL specimen. Lower preopercular spine slightly longer than upper, not reaching opercular margin. Supplemental preopercular spine usually absent, present only on right side in 152 mm SL specimen. Finger-like interopercular flap present; margin of interopercle smooth. Maxilla reaches or beyond anterior margin of eye (beyond it). Anterior portion of upper jaw with some large conical or small to large caniniform (small caniniform) teeth medially. Palatine teeth irregularly arranged in usually two, sometimes three or four rows (two); row number tending to increase with growth. Vomerine teeth irregularly arranged in one or two (one) rows anteriorly, one to four (one) 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 144 mm SL and smaller specimens, usually partly or mostly covering ventral margin of cheek region in larger specimens (partly covering), rarely tubes not covering cheek region in some specimens. Posterior tip of pelvic fin reaching anal-fin origin to base of fourth anal-fin ray (reaching base of second anal-fin ray). Posterior margin of caudal fin tending to change with growth, slightly rounded or mostly straight by 212 mm SL, mostly straight or slightly concave by 339 mm SL, slightly concave in larger specimens (damaged in holotype).

Color in alcohol. Color of holotype completely faded ( Fig. 12 A). In other specimens ( Fig. 11 ), ground color of head and body pale brown to dark brown above, paler below. Dorsal surface of head and body with many darker dots or small white spots, or without dots and spots. Some specimens with two distinct or indistinct darker bands below second dorsal fin. Side of body with or without gray band. First and second dorsal, and pectoral fins with small pale to dark brownish spots; those on pectoral fin tending to form bands. Pelvic fin pale brown or brown, with or without darker spots tending to form bands; outer margin of pelvic fin paler. Anal fin pale in smaller specimens, with melanophores along rays posteriorly in 221 mm SL or larger specimens; melanophores scattered over most of anal fin in 287 mm SL or larger specimens. Caudal fin with two to four black spots irregularly arranged posteroventrally in 155 mm SL or smaller specimens, with three or four black spots serially arranged posteroventrally along caudal fin margin in larger specimens; other areas of caudal fin with several small pale brown or brown spots or with indistinct irregular pale to dark brown markings.

Distribution. Known from southern Australia, from Cape Everard, Vic (149°16’E) to Kalbarri, WA (27°42’S), including Tas and SA, mainly on shallow sand patches among seagrasses in bays and large estuaries in depths from 1 to 30 m (e.g., Last et al., 1983; Hoese et al., 2006; Gomon, 2008; this study).

Size. Maximum length 90 cm ( Last et al., 1983). The largest specimen examined in the present study was 493 mm SL (577 mm TL) ( Fig. 11 ).

Remarks. The holotype of P. speculator has 12 second dorsal-fin rays, whereas other specimens possessed 13–14 (usually 14). Because all specimens conformed closely with the other diagnostic characters, incuding other counts and proportional measurements ( Table 4 ), the occurrence of 12 second dorsal-fin rays in the holotype is regarded as a rare intraspecific variation.

Platycephalus speculator most closely resembles P. caeruleopunctatus (see Remarks under P. caeruleopunctatus for a comparison of the two species). The former is also similar to P. f uscus, P. endrachtensis , P. westraliae , P. angustus and P. australis sp. nov. (described below) from Australia, and P. indicus and P. cultellatus from the Indo-West Pacific in having a finger-like interopercular flap, but separable from them in having usually 14 second dorsal- and anal-fin rays (vs. usually 13 rays).

Platycephalus castelnaui Macleay, 1881 ( Fig. 12 B) and Planiprora melsoni Whitley, 1945 ( Fig. 12 C) were regarded as junior synonyms of P. speculator by Paxton & Hanley (1989) and Hoese et al. (2006), but without justification. However, the synonymy of P. speculator and P. castelnaui is supported in this study on the basis of sharing 14 dorsal- and anal-fin rays, 13 gill rakers in total, a narrower interorbit (10.5% HL) and suborbital width (8.2% HL), and a finger-like interopercular flap present (see also Table 4 ). Although only the head (118 mm in length) of the holotype of Planiprora melsoni was retained, comparison with a non-type specimen of P. speculator with a similar head length (WAM P. 24537, 404 mm SL, 120 mm HL) showed the head proportional measurements to agree closely (SNL 26.3% HL, OD 16.6%, UJL 32.3%, LJL 49.5%, IW 12.4%, POL 57.6%, SW 9.0% in WAM P.24537; see Table 4 ), confirming their conspecificity.

Figures

FIGURE 11. (A) Dorsal and (B) lateral views of Platycephalus speculator, WAM P. 25720 - 001, 493 mm SL, Five Fathom Bank, WA.

FIGURE 12. Dorsal views of holotypes of (A) Platycephalus speculator, SMNS 1570, 256 mm SL, Hobson's Bay, Vic, (B) Platycephalus castelnaui, AMS I. 16354 - 001, 281 mm SL, King George Sound, WA and (C) Planiprora melsoni, AMS IB. 1367, 118 mm HL, beach at Geraldton, WA.

Tables

TABLE 4. Comparison of counts and proportional measurements of Platycephalus speculator.

SL (mm) Counts:	Holotype SMNS 1570 256	Holotype of Holotype of Platycephalus castelnaui Planiprora melsoni AMS I.16354-001 AMS IB.1367* 281 –	Non-types n = 18 117–493
D1	I + VIII + 0	I +VIII + 0 –	I + VII–VIII + 0–I (usually I + VIII + 0)
D2 A P1 C	12 13 2 + 11 + 6 = 19 –	14 – 14 –? +? +? = 18 – – –	13–14 (usually 14) 13–14 (usually 14) 1–2 + 10–13 + 5–7 = 18–20 12–13 (usually 12)
LLS (spines) OBS	85 (1) –	– (1) – (–) – –	77–86 (1–2) 97–117
GR As % SL: HL PDL	3 + 10 = 13 31.9 34.7	3 + 10 = 13 – 29.8 – 32.8 –	2–3 + 9–11 = 11–14 29.7–32.3 31.4–34.1
LD1B LD2B	21.0 33.2	19.7 – 36.2 –	17.3–22.4 33.7–37.8
LAB SNL OD UJL	36.9 8.2 6.7 10.7	38.5 – 8.0 – 5.9 – 10.4 –	36.5–40.8 7.8–8.6 4.7–7.4 9.6–11.5
LJL IW	15.9 3.1	14.6 – 3.1 –	14.7–16.7 1.9–4.6
POL SW P1L P2L	17.3 2.3 16.0 25.4	17.3 – 2.3 – – – – –	15.7–18.2 2.0–3.1 14.4–18.5 23.3–26.9
CL As % HL:	–	– –	15.0–20.7
SNL OD UJL LJL	25.8 20.9 33.5 49.8	26.8 26.0 19.8 17.8 34.7 35.7 49.0 48.1	24.8–27.1 15.5–23.1 32.3–36.2 48.2–52.0
IW POL	9.6 54.2	10.5 13.4 53.9 55.6	5.8–14.6 51.2–59.1
SW * Head only.	7.1	8.2 10.0	6.1–10.0