Psettina gigantea Amaoka, 1963

Amaoka, Kunio & Ho, Hsuan-Ching, 2019, The lefteye flounder family Bothidae (Order Pleuronectiformes) of Taiwan, Zootaxa 4702 (1), pp. 155-215 : 204

Psettina gigantea Amaoka, 1963

Combscaled flounder; łŝľ

Figure 9C ; Table 12–13

Psettina gigantea Amaoka, 1963a:56 (Type locality: Mimase, Kochi Prefecture, Japan). Shen, 1983:26; Shen in Shen et al., 1993:572; Shen & Wu, 2012:754.

Psettina profunda (not of Weber): Kamohara, 1959:7; Chen & Weng, 1965:46.

Specimens examined. NMMB-P03187 (4, 102.1–106.1), Taichung, central western Taiwan, 6 Apr. 2002; NMMB- P23236 (11, 88.2–108.9), Dong-gang, 20 Feb. 2016 ; NMMB-P23284 (2, 112.8–112.9), Ke-tzu-liao, 3 Apr. 2016. More specimens deposited in NMMB-P.

Diagnostic features. D 92–102; A 74–82; P 11–13; C 2+13+2=17; LLs 56–63; GR 0+6–8=6–8; vert. 10+29– 30=39–40.

Body compressed, elliptical, deepest at anterior 1/3 of body (44.1–47.4% SL). Head more than half of body depth (22.7–26.8% SL); front profile of head with slight concavity anterior of ventral margin of lower eye; head profile gently convex. Snout much shorter than eye diameter. Eye diameter subequal to upper jaw. Interorbital space very narrow, concave, sometimes with ridges on anterior and posterior portions.

Mouth rather large for this genus, upper-jaw length on ocular side 7.4–8.9% SL; maxilla extending to anterior margin of lower eye. Short knob at mandibular symphysis. Teeth on upper jaw regularly biserial; those in inner row larger than outer row, somewhat enlarged anteriorly; teeth on lower jaw uniserial. Gill rakers short, pointed at tip and not serrated on lower limb; absent on upper limb. Scales on ocular side small, ctenoid with row of long ctenii, cycloid on blind side. Pectoral fin on ocular side short (15.4–18.1% SL); that of blind side very short, about 2/3 of ocular side.

Coloration. Ocular side of body uniformly darkish brown with a row of indistinct dark ringed blotches along dorsal and ventral margins of body; snout and both jaws dark; blind side of body uniformly milky white.

Size. Reaching 110 mm SL in Taiwan; up to about 130 mm SL in southern Japan ( Amaoka, 2016).

Distribution. Northeastern, western and southwestern Taiwan; southern Indonesia, northeastern Australia to southern Japan ( Amaoka, 2016).

Remarks. This species differs from its congeners in lacking distinct blotches on body and fins. Small individuals were sometimes confused with P. tosana , but can be separated by having more lateral-line scales and a larger mouth.

Distribution. Northeastern, western and southwestern Taiwan; from Coral Sea throughout southern Indonesia, to southern Japan and southern Korea ( Amaoka, 2016).

Remarks. This species resembles P. brevirictus and P. variegatus in body shape, coloration and position of blotches. It, however differs from the former in having many more scales in the lateral line, fewer gill rakers on the lower limb, and from the latter in having fewer scales in the lateral line and fewer gill rakers on the lower limb. Chen & Weng (1965) recorded 56 lateral-line scales for a specimen which they described as P. brevirictus but which actually belongs to P. iijimae .

Figures

FIGURE 9. A–B. Parabothus taiwanensis, NMMB-P 25725, male, 122.3 mm SL (A) and NMMB-P 23214, female, 101.6 mm SL (B). C. Psettina gigantea, NMMB-P23236, 98.2 mm SL. D. Psettina iijimae, NMMB-P26402, 68.3 mm SL. E. Psettina tosana, NMMB-P 23211, 81.5 mm SL. F. Psettina variegata, NMMB-P23202, 121.9 mm SL.