Taxonomic revision of the flathead fish genus Platycephalus Bloch, 1785 (Teleostei: Platycephalidae) from Australia, with description of a new species
Author
Imamura, Hisashi
text
Zootaxa
2015
3904
2
151
207
journal article
10.11646/zootaxa.3904.2.1
adefe9de-0ca5-479a-b736-ad242c7f0fe4
1175-5326
233552
CEC37C0D-A25D-43C1-8F3C-127919282F35
Platycephalus richardsoni
Castelnau, 1872
Common English name: Tiger flathead (
Figs. 23–24
;
Fig. 9
)
Platycephalus richardsoni
Castelnau, 1872
: 82
(
type
locality: Melbourne markets, Vic,
Australia
);
McCulloch, 1929
: 400
;
Last
et al
., 1983
: 333
, fig. 28.21;
Paxton & Hanley, 1989
: 469
;
Grant, 2004
: 188
, unnumbered pl.;
Hoese
et al
., 2006
: 943
; Imamura, 2006: 305, tab. 1;
Gomon, 2008
: 520
, unnumbered fig.
Neoplatycephalus grandis
Castelnau, 1872
: 87
(
type
locality: Melbourne markets, Vic,
Australia
);
McCulloch, 1929
: 402
.
Platycephalus macrodon
Ogilby, 1885
: 226
(
type
locality: Port Jackson, NSW,
Australia
);
McCulloch, 1929
: 401
.
Neoplatycephalus macrodon
:
Whitley, 1931b
: 159
.
Neoplatycephalus
(
Colefaxia
)
macrodon
:
Whitley, 1935
: 249
.
Neoplatycephalus richardsoni
:
Whitley, 1964
: 57
;
May & Maxwell, 1986
: 272
, unnumbered fig.;
Hutchins & Swainston, 1986
: 127
, fig. 197;
Knapp, 1991
: 29
, tab. 1;
Kuiter 1993
: 101
, unnumbered fig.;
Kuiter, 1994
: 518
, fig. 461.
Material examined.
21 specimens
(
91.6–461 mm
SL
, from southeastern
Australia
):
AMS
B.6541,
holotype
of
Platycephalus macrodon
Ogilby,
1885
, 281 mm
SL
, Port Jackson,
NSW
;
AMS
E.
581, 165 mm
SL
, Oyster Bay, Tas (
42.7°S
,
148.1°E
), date unknown;
AMS
E.3013,
2 specimens
,
174–212 mm
SL
, Bass Strait, between Gabo and Babel Islands, date unknown;
AMS
I.23871-002,
194 mm
SL
,
4 miles
off Whale Beach,
NSW
(
33°37’S
,
151°22’E
),
54 m
depth,
10 Oct. 1976
;
AMS
I.26026-001,
266 mm
SL
, off Clarence River,
NSW
(
29°26’S
,
153°26’E
),
11 Oct. 1985
;
AMS
I.33329-002,
461 mm
SL
, Norah Head,
NSW
(
33°17’S
,
151°35’E
), 1984;
AMS
I.40292-001,
231 mm
SL
, off Bermagui,
NSW
(
36°23’S
,
150°21’E
),
428–468 m
depth,
2 May 2000
;
AMS
IB.
507, 440 mm
SL
, Wineglass Bay, Tas (
42°10’S
,
148°18’E
),
18 June 1940
;
AMS
IB.
7599, 379 mm
SL
,
AMS
IB.
7600, 310 mm
SL
,
AMS
IB.
7602, 321 mm
SL
, Lakes Entrance, Vic (
37°53’S
,
148°00’E
), 1966;
CSIRO
3534-09,
246 mm
SL
, south of Disaster Bay,
NSW
(
37°23’S
,
149°58’E
–
37°22’S
,
149°58’E
),
31–36 m
depth,
12 Aug. 1993
;
CSIRO
A 1612,
91.6 mm
SL
,
3 miles
NE of Brush Island,
NSW
(
35°32’S
,
150°25’E
),
25 Jan 1946
;
CSIRO
A
1614, 113 mm
SL
, Eden,
NSW
(
37°04’S
,
150°56’E
),
90 m
depth,
28 Apr. 1953
;
CSIRO
CA
135, 323 mm
SL
, Sydney fish market,
NSW
,
5 July 1977
;
NMV
A
3786, 226 mm
SL
,
24 km
southwest of Lakes Entrance, eastern Bass Strait, Vic (
38°03’S
,
147°50’E
),
25–45 m
depth,
1 Oct. 1983
; QM I.
22311, 307 mm
SL
, Eden,
NSW
(
37°04’S
,
149°55’E
),
14 Aug. 1985
; QM I.
22302, 365 mm
SL
, QM I.
22307, 349 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; caudal-fin rays 13; pored lateral-line scales 65–74; gill rakers 2–4 + 10–13 = 12–17; orbital diameter 18.4–24.1% HL; interorbital width 10.1–15.7% HL; postorbital length 49.7–56.2% HL; suborbital width 4.9–9.4% HL; occipital and lower half of suborbital regions scaled in larger specimens; margin of interopercle smooth; one or two large caniniform teeth anteromedially on upper jaw; all or most pored lateral-line scales usually with two pairs of sensory ducts and exterior openings posteriorly; fleshy sensory tubes from suborbitals and preopercle not covering cheek region; swimbladder present; abdominal cavity dark brown or black.
Description.
Counts and measurements shown in
Table 9
.
FIGURE 23.
(A) Dorsal and (B) lateral views of
Platycephalus richardsoni
, AMS IB.7600, 310 mm SL, Lakes Entrance, Vic.
FIGURE 24.
Dorsal view of holotype of
Platycephalus macrodon
, AMS B.6541, 281 mm SL, Port Jackson, NSW.
TABLE 9.
Comparison of counts and proportional measurements of
Platycephalus richardsoni
.
Holotype
of
P. macrodon
Non-types
AMS B.6541 n = 20 SL (mm) 281 91.6–461 Counts:
D
1 I
+ VIII + 0 I + VII–VIII + 0–I
(often I + VIII + 0) D
2 14 13–14
(usually 14) A 14 13–14 (usually 14) P1 2 + 10 + 8 =
20 1–2
+ 9–12 + 7–8 = 19–22
(usually 20) C 13 13
LLS (spines) 70 (3) 65–74 (1–2) OBS – 81–95 GR 3 + 11 =
14 2–4
+ 10–13 = 12–17 As % SL:
HL 33.3 34.1–36.2 PDL 34.3 34.4–37.6 LD1B 21.7 16.4–22.2 LD2B 32.5 30.0–33.1 LAB 33.4 30.2–35.1 SNL 9.1 8.8–10.3 OD 6.7 6.4–8.6 UJL 12.3 12.6–14.3 LJL 17.0 16.5–19.1 IW 4.4 3.6–5.5 POL 17.8 17.2–19.3 SW 2.0 1.7–3.2 P1L 16.0 14.6–18.0 P2L 23.8 21.9–26.1 CL 15.6 15.1–19.3 As % HL:
SNL 27.2 26.0–28.9 OD 20.2 18.4–24.1 UJL 36.8 36.9–39.9 LJL 51.2 48.5–53.4 IW 13.2 10.1–15.7 POL 53.4 49.7–56.2 SW 6.1 4.9–9.4
Snout, interorbit and occipital region scaled; lower half of suborbital region naked in
165 mm
SL or smaller specimens, scaled in larger specimens; area anteroventral to eye naked. Interorbit narrower than orbital diameter. Upper iris lappet simple, weakly pointed; lower absent. Nasal spine usually absent, rarely one spine present in some specimens. Preorbital spine present in smallest (
92 mm
SL) specimen, absent in larger specimens. One suborbital spine present below posterior margin of eye in
165 mm
SL or smaller specimens, absent in larger specimens (except in
379 mm
SL specimen with two spines below posterior margin of eye). Three preopercular spines present; middle spine usually slightly longer than uppermost spine (more than twice length in some specimens, but not reaching opercular margin); lowermost small. Supplemental preopercular spine usually absent (present in
93 mm
and
307 mm
SL specimens). Interopercular flap absent; margin of interopercle smooth. Maxilla usually not reaching, or reaching just beyond anterior margin of pupil (to middle of eye in some specimens). Upper jaw with one or two large caniniform teeth anteromedially. Palatine teeth in two rows, villiform or small conical in outer row, small to moderate caniniform in inner row. Vomerine teeth in one row anteriorly, one or two rows posteriorly, becoming larger posteriorly. All or most pored lateral-line scales usually with two pairs of sensory ducts and exterior openings posteriorly, some scales sometimes with one, three or four pairs of ducts and openings. 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. Posterior margin of caudal fin mostly straight in smaller specimens, slightly concave in larger specimens. Swimbladder present.
Color in alcohol.
Ground color of head and body reddish-brown, pale or dark brown above, paler brown below. Side of body with or without a single row of purplish spots tending to form a band, or with a dark brown or purple band. First and second dorsal fins with distinct or indistinct pale brown to brown spots. Pectoral fin dusky, upper portion with brownish spots tending to form bands; lower margin of pectoral fin paler. Pelvic fin pale to dark brown; lower margin of fins paler. Anal fin pale or with melanophores along rays. Caudal fin dusky, or brown to dark brown; upper margin with or without indistinct pale brown or brown spots. Abdominal cavity dark brown or black.
Distribution.
Known from southeastern
Australia
, from off Clarence River, NSW (
29°26’S
) to Investigator Strait, SA (
137°10’E
), including Vic and Tas, on the continental shelf in depths from ca.
10 to 428 m
(e.g.,
May & Maxwell, 1986
;
Hoese
et al
., 2006
;
Gomon, 2008
; this study).
Size.
Maximum length
60 cm
SL (
Gomon, 2008
). The largest specimen examined during the present study was
461 mm
SL (caudal fin broken).
Remarks.
Platycephalus richardsoni
is most similar to
P. conatus
, but differs in having 12–17 gill rakers in total and all or most pored lateral-line scales usually with two pairs of sensory ducts and exterior openings posteriorly (see Remarks under
P. conatus
). The latter character also distinguishes
P. richardsoni
from other species of
Platycephalus
characterized by pored lateral-line scales usually with a single pair of sensory ducts and exterior openings.
Although
Paxton & Hanley (1989)
,
Kuiter (1994)
and
Hoese
et al
. (2006)
considered
P. mortoni
Macleay, 1883
to be a junior synonym of
P. richardsoni
,
Imamura (2013a)
found the former to be conspecific with
Platycephalus fuscus
Cuvier
in
Cuvier & Valenciennes, 1829
. In contrast, the junior synonymy of
Neoplatycephalus grandis
Castelnau, 1872
under
P. richardsoni
, as already pointed out by several authors (
Paxton & Hanley, 1989
;
Kuiter, 1994
;
Hoese
et al
., 2006
), is reconfirmed here, both nominal taxa having “several arborescent tubes” on the lateralline scales (see original descriptions of both species by
Castelnau, 1872
). Unfortunately, the whereabouts of the
type
specimens of
P. richardsoni
is unknown at present and the
syntypes
of
N. grandis
were apparently lost (e.g.,
Hoese
et al
. 2006
).
Platycephalus macrodon
(
Fig. 24
) was also regarded as a junior synonym of
P. richardsoni
by
Paxton & Hanley (1989)
,
Kuiter (1994)
and
Hoese
et al
. (2006)
. This synonymy is supported here due to the
holotype
of
P. macrodon
agreeing closely with the latter in pored lateral-line scale characteristics, and having no remarkable departures from the counts and proportional measurements accordied to
P. richardsoni
(
Table 9
).