Parabothus coarctatus ( Gilbert, 1905 )

Amaoka, Kunio & Ho, Hsuan-Ching, 2019, The lefteye flounder family Bothidae (Order Pleuronectiformes) of Taiwan, Zootaxa 4702 (1), pp. 155-215 : 198

Parabothus coarctatus ( Gilbert, 1905)

Greenspotted flounder; ẽafľ

Figures 8 B–C; Table 11

Platophrys coarctatus Gilbert, 1905:686 (Type locality: Pailolo Channel, Hawaii Islands, U. S. A.).

Specimens examined. NMMB-P13149 (1, 188.9) , NMMB-P13150 (1, 188.8) , NMMB-P12151 (1, 188.5), Penghu Island , 31 Dec. 2010 ; NNMB-P17686 (1, 173.0), Daxi , Yilan, 12 Nov. 2012 ; NMMB-P22242 (1 male, 195, 1 female, 137.4), Ke-tzu-liao, 21 Jan. 2015 .

Diagnostic features. D 110–117; A 89–95; P 12–14; C 2+13+2=17; LLs 87–95; GR 0+8–9=8–9; vert. 10+33=43.

Body elliptical, deepest slightly anterior of middle of body (38.6–42.3% SL). Head relatively small (26.2– 26.8% SL); upper profile of head with slight concavity in front of interorbital space. Snout round, relatively long, its length shorter than eye diameter. Eye diameter smaller than upper jaw length. Interorbital space deeply concave, its width narrower than eye diameter, wider in males than females and juveniles, 3.0–3.4% SL in males, 1.4–2.0% SL in females or juveniles.

Mouth moderately large, upper-jaw length 9% SL; maxilla extending to slightly beyond anterior margin of lower eye. Prominent knob on mandibular symphysis. Teeth on both jaws small, uniserial, some pairs of anterior teeth enlarged, canine-like; lateral teeth on lower jaw somewhat larger than those on upper jaw. Gill rakers on lower limb of first arch, moderate in size, not serrate; absent on upper limb.

Scales small, ctenoid with moderate ctenii on ocular side; scales on blind side cycloid. Pectoral fin on ocular side short (14.3–15.2% SL).

Coloration. Ocular side of body grayish brown; a series of obtuse greenish yellow blotches with dark margins near dorsal and ventral margins of body; two dark small spots on junction between curve and straight portion of lateral line, two on middle and one on posterior portions; head with greenish yellow spots and dashes, each with dark margins; dorsal and anal fins with a regularly arranged series of dark blotches; body on blind side milky white.

Size. Reaching 189 mm SL in Taiwan; up to 225 mm SL in Japan ( Amaoka, 1969)

Distribution. Northeastern, western and southwestern Taiwan; southern Japan to Coral Sea, Hawaii Islands ( Amaoka et al., 1997).

Remarks. This species resembles Parabothus kiensis in body shape, but differs in smaller eyes, smaller scales and the shape and abundance of blotches on the body. This species exhibits sexually dimorphism and ontogenetic changes of the interorbital width.

Figures

FIGURE 8. A. Neolaeops microphthalmus, NMMB-P 20986, 110 mm SL. B–C. Parabothus coarctatus, NMMB-P13151, male, 188.5 mm SL (B) and NMMB-P13149, female, 188.9 mm SL (C). D–E. Parabothus kiensis, NMMB-P18021, male, 133.0 mm SL (D) and NMMB-P30894, female, 157 mm SL (E). F. Parabothus polylepis, NMMB-P26403, female, 119.7 mm SL.