Grammatobothus polyophthalmus ( Bleeker, 1865 )

Amaoka, Kunio & Ho, Hsuan-Ching, 2019, The lefteye flounder family Bothidae (Order Pleuronectiformes) of Taiwan, Zootaxa 4702 (1), pp. 155-215 : 189

Grammatobothus polyophthalmus ( Bleeker, 1865)

Manyeyed flounder, Threespot flounder; ȇṯƍáľ

Figures 6 G–H; Table 9

Platophrys polyophthalmus Bleeker, 1865:46 (Type locality: Sumatra, Indonesia).

Gramatobothus polyophthalmus: Norman, 1926:253 ; Ho et al., 2009:6.

Specimens examined. NMMB-P04602 (1 male, 127.1), Yilan, 16 Jul. 1965 ; NMMB-P25740 (1, 75.7), Ke-tzu-liao, 27 Jun. 2016 ; NMMB-P28527 (1 male, 116.9), Ke-tzu-liao, 8 Feb. 2018 .

Diagnostic features. D 75–84; A 64–67; P 15–16; C 2+13+2=17; LLs 71–80; GR 2–5+7–9=12–13; vert. 10+28=38.

Body deep ovate, deepest near middle part of body (61.8–66.0% SL). Head much shorter than half of body depth (26.6–27.8% SL); upper profile of head steep with distinct concavity in front of ventral margin of upper eye. Snout shorter than eye diameter. Rostral spine absent. Eye diameter slightly shorter than upper-jaw length. Interorbital space with a narrow concave space, its width about 1/3 of eye diameter.

Mouth small, upper-jaw length 8.5–8.8% SL; maxilla extending to or slightly beyond anterior margin of lower eye; several short and blunt prominent spines along upper jaw. Teeth on both jaws uniserial, upper-jaw teeth becoming gradually smaller backward; all teeth of lower jaw about same size, similar to anterior teeth of upper jaw. Gill rakers very small on upper limb and slender on lower limb, all not serrated.

Scales on ocular side very small, ctenoid with one row of short ctenii on posterior margin, cycloid on blind side. Second to tenth rays of dorsal fin prolonged, lengths in males longer than those in females; 4th or 5th rays longest, its length in males slightly longer than head; fin membranes behind prolonged rays deeply incised, and membrane on posterior surface of prolonged rays expanded, forming pinniform rays. Pectoral-fin rays on ocular side very long in males, length of pectoral fin 19.7–37.4% SL, not elongate in females.

Coloration. Ocular side of body pale brownish, with three large prominent dark ocelli, two anteriormost above and below pectoral fin, one posteriormost midway along straight portion of lateral line, and with many more or less regularly distributed small, distinct, dark spots (light blue in fresh); one or two distinct chromosome-shaped dark bars (deep blue in fresh) above upper eye in males; dorsal and anal fins with indistinct dark blotches; pectoral fin on ocular side with broad pale cross bars. Blind side of body yellowish white.

Size. Reaching 127 mm SL off Taiwan; up to about 170 mm total length elsewhere ( Hensley & Amaoka, 2001).

Distribution. Northeastern and southwestern Taiwan; widespread in Indian and Western Pacific oceans ( Amaoka, 2016).

Remarks. Gramatobothus polyophthalmus differs from G. krempfi and G. pennatus in having 2nd to 10th dorsal-fin rays elongate (vs. 2nd to 4th in latter) and a deeper body (1.5–1.8 vs. 1.8–2.0 in HL). Ho et al. (2009) reported this species from Taiwanese waters for the first time.

Figures

FIGURE 6. A–B. Crossorhombus kobensis, NMMB-P22249, male, 69.1 mm SL. C–F. C. valderostratus, NMMB-P22286, male, 70.7 mm SL (C–D) and female, 66.2 mm SL (E–F). G–H. Grammatobothus polyophthalmus, NMMBA 28527, 116.9 mm SL, photo by K. Koeda.