Arnoglossus yamanakai, Fukui, Yamada & Ozawa, 1988

Amaoka, Kunio & Ho, Hsuan-Ching, 2019, The lefteye flounder family Bothidae (Order Pleuronectiformes) of Taiwan, Zootaxa 4702 (1), pp. 155-215 : 164-165

Arnoglossus yamanakai Fukui & Ozawa, 1988

Tokai lefteye flounder; Ɯvr¥6ľ

Figure 1H ; Tables 1–2

Arnoglossus yamanakai Fukui & Ozawa, 1988:923 (Type locality: South China Sea). Fukui et al. (1990):215.

Arnoglossus japonicus Hubbs, 1915:454 (in part, paratype).

Arnoglosus sp. A: Ozawa & Fukui, 1986:384, 409 (larvae).

Specimens examined. NMMB-P22849 (2, 87.2–87.3), Ke-tzu-liao, 28 Mar. 2015 ; NMMB-P23270 (2 males, 86.2– 97.9, 2 females, 82.7–88.9), Ke-tzu-liao, 28 Feb. 2016 ; NMMB-P23314 (1 male, 94.9), 18 Mar. 2016 ; NMMB- P25674 (3 males, 1 female, 92.7–95.4), Ke-tzu-liao, 27 Dec. 2016 ; NMMB-P25685 (5 males, 1 female, 89.5–95.7), 2 Apr. 2015 ; NMMB-P25696 (1 female, 84.7), 20 Jan. 2017 ; NMMB-P25715 (1 male, 1 female, 85.9–89.8), Ketzu-liao, 22 Apr. 2016

Diagnostic features. D 99–107; A 77–83; P 12–13; C 3+11+3=17; LLs 60–68; GR 0+7–8=6–9; vert. 11– 12+33–34=44–45.

Body elongated, greatest depth near anterior 1/3 part of body (34.2–38.0% SL). Head small, its length about 67–76% body depth (23.8–27.0% SL); front of head with very slight concavity in front of upper eye; head profile gentle, same in both sexes. Snout rather round, snout length shorter than eye diameter. Rostral spine absent on tip of snout in both sexes. Eye diameter much shorter than upper jaw length; upper eye close to dorsal margin of head, its width about 1/3 of eye diameter. No orbital spines in both sexes. Interorbital space with narrow bony ridge extending from anterior margin of lower eye to posterior space between both eyes.

Mouth large, upper-jaw length on ocular side 8.3–10.5% SL; anterior tip of upper jaw on about same vertical line to anterior tip of lower jaw or slightly beyond; maxilla extending to or slightly behind anterior margin of lower eye. Teeth on both jaws biserial, outer row larger than inner row, 55–71 teeth on upper jaw of ocular side, 23–35 teeth on lower jaw of ocular side; numerous very small inner row teeth, covered by skin. Gill rakers only on lower limb, slender with spines on inner margin of distal half.

Scales rather large and very deciduous, weakly ctenoid on ocular side, cycloid on blind side. Second dorsal-fin ray elongate in males, about 1.8–3.6 in HL; no elongate ray in females. Pectoral fin on ocular side small, longer than half of head length (15.1–17.4% SL); that on blind side very short. Caudal fin pointed, upper 2–3 and lower 3 rays simple, and middle rays branched into 2.

Coloration. Ocular side of body uniformly pale brownish without distinct blotches or spots; distal margin of dorsal fin from posterior margin of head to middle part of body dark in males, not dark in females; blind side of body uniformly milky white.

Size. Reaching 98 mm SL in Taiwan; up to 123 mm SL in East China Sea ( Fukui et al., 1990).

Distribution. Southwestern Taiwan off Ke-tzu-liao, Kaohsiung, at depth not more than 100 m; Western Pacific Ocean ( Amaoka, 2016)

Remarks. This species resembles A. japonicus in having an elongate second dorsal-fin ray in males and similar numbers of dorsal- and anal- fin rays, but differs by characters described in the remarks of A. japonicus . The adult size is smaller than A. japonicus . This is the first record of the species from Taiwan.

Figures

FIGURE 1. A–B. Arnoglossus japonicus, NMMB-P23187, male 121.0 mm SL (A) and female, 110.2 mm SL (B). C. A. macrolophus, NMMB-P 23204, male, 81.1 mm SL. D–E. A. oxyrhynchus, NMMB-P23317, male, 148.0 mm SL (D) and female, 171.1 mm SL (E). F. A. polyspilus, NMMB-P29041,164 mm SL. G. A. tenuis, NMMB-P25684, 64.5 mm SL. H. A. yamanakai, NMMB-P25685, 95.0 mm SL.