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
Kamoharaia megastoma
(
Kamohara, 1936
)
Widemouthed flounder;
öpľ
Figures 7
B–C;
Table 10
Chascanopsetta megastoma
Kamohara, 1936:308
(Ttype locality:
Kochi Prefecture
,
Japan
).
Chen & Weng, 1965:61
.
Kamoharaia megastoma
:
Kuronuma, 1940:36
;
Shen, 1983:34
; Shen in
Shen
et al.
, 1993:570
;
Ho
et al.
, 2009:11
;
Shen & Wu,
2012:752.
Specimens examined.
NMMB-P17856
(1, 186.6), Nan-fang-ao,
13 Oct. 2012
;
NMMB-P21088
(1, 109), Donggang,
30 Mar. 2014
;
NMMB-P22267
(1, 164.2), Dong-gang,
7 Nov. 2013
;
NMMB-P25330
(1, 95.0), Dong-gang,
26 May 2013
;
NMMB-P29037
(1, 95.4), Ke-tzu-liao,
18 Mar. 2018
. More specimens deposited in NMMB-P.
Diagnostic features.
D 109–112; A 84–88; P 12; C 3–5+7–11–5=17; LLs 126–132; GR 0–3+7–8; vert. 13+39– 40=52–53.
Body elliptical, strongly compressed; greatest depth near tip of pectoral fin (34.1–38.3% SL). Caudal peduncle narrow, its depth 5.1–5.7% SL. Head small, its length 17.1–20.1% SL; upper profile of head deeply concave anterior of interorbital area, and more or less convex in front of upper eye. Snout much shorter than eye diameter. Eyes small, about 1/3 of upper jaw, separated by narrow flat ridge.
Mouth very large, upper-jaw length about 14.5–19.2% SL; maxilla extending well beyond posterior margin of lower eye; tip of upper jaw protruding beyond tip of snout by half eye diameter. Teeth on upper jaw uniserial, 3 or 4 pairs of larger teeth anteriorly, narrow tooth band on posterior half; lower jaw teeth uniserial, anteriorly 3 pairs of large inward curved canine teeth, posterior teeth becoming smaller. Tip of vomer projecting into mouth cavity. Gill rakers short and slender without serration on lower limb, rudimentary on upper limb.
Scales on both sides very small, cycloid. First ray of dorsal fin elongate, its length
2.5–2.8 in
HL. Pectoral fin on ocular side about half of that on blind side. Caudal fin slender and round, with 3–5 unbranched rays dorsally and ventrally.
Coloration.
Ocular side of body uniformly brownish with many irregular dark blotches; median fins and pectoral fin on ocular side dark except for basal portion. Blind side of body yellowish white.
Size.
Reaching
187 mm
SL in
Taiwan
; up to
220 mm
SL elsewhere (
Hensley & Amaoka, 2001
).
Distribution.
Northeastern and southwestern
Taiwan
; widespread in the Indo-Australian archipelago to southern
Japan
(
Amaoka, 2016
).
Remarks.
This species resembles
Chascanopsetta lugubris
in having an extremely large mouth, but can be easily distinguished in having the tip of the maxilla strongly extending beyond the tip of the snout, in having 3 pairs of canine teeth on the tip of the lower jaw and in the tip of the vomer projecting into the mouth cavity. In juveniles of
100–120 mm
SL, both jaws are not particularly protruding (
Amaoka, 2016
).