The lefteye flounder family Bothidae (Order Pleuronectiformes) of Taiwan
Author
Amaoka, Kunio
Author
Ho, Hsuan-Ching
text
Zootaxa
2019
2019-12-04
4702
1
155
215
journal article
24734
10.11646/zootaxa.4702.1.18
d2251320-5eef-450d-9703-2d2004e4962b
1175-5326
3562779
9108DB7D-3722-4F5C-BD76-F387E813BECB
Chascanopsetta lugubris
Alcock, 1894
Pelican flounder;
ƛpłāľ
Figure 4A
;
Table 5
Chascanopsetta lugubris
Alcock, 1894:129
(
Type
locality:
Bay
of Bengal, Indian Ocean).
Chen & Weng, 1965:60
;
Chen, 1969:215
;
Shen, 1983:35
;
Shen, 1984:447
;
Chen & Yu, 1986:820
; Shen in
Shen
et al.
, 1993:568
;
Tongboonkua
et al.
, 2018:179
.
Chascanopsetta lugbris lugbiris
:
Amaoka & Yamamoto, 1984:209
;
Shen & Wu, 2012:749
.
Specimens examined.
NMMB-P001382
(4 of 10, 142.2–243.9), Dong-gang, no date
;
NMMB-P1985
(10, 135.3– 186.0), Dong-gang,
13 Jun. 1983
;
NMMB-P5794
(2, 125.2–166.3), Dong-gang,
13 Mar. 2003
;
NMMB-P7386
(1, 144.7), Dong-gang,
3 Apr. 2004
;
NMMB-P8153
(4 of 5, 140.7–177.0), Dong-gang,
11 Jun. 2004
;
NMMB-P19174
(1 of 2, 202.0), Dong-gang,
3 Nov. 2011
;
NMMB-P22225
(2, 157.8–189.8), Dong-gang,
13 Mar. 2015
;
NMMB- P22260 (1, 73.8), Dong-gang,
11 Feb. 2015
;
NMMB-P25745
(1, 296.4), Dong-gang,
30 Mar. 2017
; more specimens in NMMB-P collection.
Diagnostic Features.
D 115–124; A 78–86; P 14–17; C 2+13+2=17; LLs 157–197; GR 0+1–3=1–3; vert. 17+38–40=55–57.
Body elongate elliptical, rather soft and flabby; greatest depth at posterior margin of abdominal cavity (24.9– 30.5% SL). Caudal peduncle narrow, its depth about 14–19 % of body depth. Head relatively large (19.8–22.7% SL); upper profile of head with slight concavity anterior of dorsal margin of lower eye. Snout blunt and short, its length about 2/3 of eye diameter. Eyes separated by narrowly flat space, its width about 1/3 to 1/4 of eye diameter.
Mouth very large, upper-jaw length 14.5–17.6% SL; maxilla extending well beyond posterior margin of lower eye; tip of lower jaw reaching a little beyond tip of upper jaw. Teeth on both jaws uniserial, slender; upper-jaw teeth small on posterior half; lower-jaw teeth curved inward and depressible, posteriormost teeth smaller than others. Gill rakers on lower limb, rudimentary. Scales on both sides very small, cycloid. Anterior rays of dorsal fin somewhat elongated, free from fin membrane except for base. First ray of anal fin connected with last ray of pelvic fin by narrow membrane. Pectoral fin on both sides slender, length on ocular side 10.3–14.6% SL. Caudal fin slender, with round tip.
Coloration.
Ocular side of body uniformly dark brownish with many small irregularly arranged dark blotches; light blue on peritoneum; median fins dark without marking; paired fins paler than body. Blind side of body light brownish except for light blue peritoneum.
Size.
Reaching
296 mm
SL in
Taiwan
; up to
380 mm
SL elsewhere (
Hensley & Amaoka, 2001
).
Distribution.
Widespread around
Taiwan
; Indian to Western Pacific oceans (
Amaoka & Yamamoto, 1984
).
Remarks.
This species had been regarded as two subspecies,
C. lugubris lugubris
from Pacific Ocean and
C. lugubris danae
from Atlantic Ocean (
Amaoka & Yamamoto (1984)
. But
Munroe (2003)
graded up to species based on clearly different counts of the gill rakers. Recently
Tongboonkua
et al.
(2018)
showed generic divergence between
C. lugubris
and
C. danae
.
We followed their results, though it may be problematic in identification of species.
Caschanopsetta lugubris
differs from
C. prognatha
in having the tip of the lower jaw slightly beyond the tip of the upper jaw and the lower-jaw length being shorter than HL (
Amaoka, 2016
).