Bothus pantherinus ( Rüppell, 1830 )

Amaoka, Kunio & Ho, Hsuan-Ching, 2019, The lefteye flounder family Bothidae (Order Pleuronectiformes) of Taiwan, Zootaxa 4702 (1), pp. 155-215 : 172-173

Bothus pantherinus ( Rüppell, 1830)

Leopard flounder; ṅȓľ

Figures 3 G–H; Table 4

Rhombus pantherinus Rüppell, 1830:121 (Type locality: Mohila, Red Sea).

Bothus pantherinus: Regan, 1920:212 ; Chen & Weng, 1965:53; Shen, 1983:25; Shen in Shen et al., 1993:568; Shen & Wu, 2012:749.

Grammatobothus krempfi :? Shen in Shen et al., 1993:569.

Specimens examined. NMMB-P01621 (1 male, 167.6), Hou-bi-hu, Hengchun , 10 Mar. 1994 ; NMMB-P04159 (1 male, 154.9), Penghu, 1 Aug. 1957 ; NMMB-P07591 (1, 86.6), Shan-hai, Hengchun , 29 Jun. 2004 ; NMMB-P09839 (92.1), Hai-ko, Checheng , 18 Aug. 2008 ; NMMB-P23285 (1 male, 116.5), Ke-tzu-liao, 7 Apr. 2016 ; NMMB- P24608 (1 male, 123.9) , NMMB-P24609 (1 female, 116.8), Ke-tzu-liao, 5 Jul. 2016 ; NMMB-P24874 (4 females, 127.4–150.1), Ke-tzu-liao, 13 Jul. 2016 ; NMMB-P24875 (4 males, 122.3–145.3; 4 females, 105.0–114.0), Ke-tzuliao , 27 Jun. 2016 ; more specimens in NMMB-P collection.

Diagnostic Features. D 86–93; A 67–71; P 10–12; C 2+13+2=17; LLs 77–86; GR 0–4+6–9=6–12; vert. 10+27–29=37–39.

Body compressed, ovoid, greatest depth at middle part of body (50.1–59.7% SL). Head length about equal to half of body depth (26.1–29.3% SL); upper profile of head without distinct concavity anterior of dorsal margin of upper eye, steep in both sexes. Snout length about equal to eye diameter. Rostral spine present on tip of snout in males, absent or low knob in females and juveniles. Eye diameter much shorter than upper jaw. Males with 1–4 small orbital spines at anterior margins of both eyes and one strong spine at anterior margin of lower eye in males, spines absent in females and juveniles; usually several tentacles on hind margins of both eyes in males. Interorbital space deep and wide concave, its width wider in males than females and juveniles.

Mouth large, upper-jaw length 9.0–10.2% SL; maxilla extending to, or slightly beyond anterior margin of lower eye. Teeth on upper jaw biserial anteriorly, uniserial posteriorly; teeth on lower jaw uniserial, anterior teeth larger than posterior ones. Gill rakers only on lower limb, short and slender, pointed at tip, not serrate.

Scales on ocular side small, ctenoid with moderate ctenii in length, cycloid on blind side. Pectoral-fin rays extremely elongate in males on ocular side, pectoral-fin length 45.8–106.0% SL in mature males, 17.1–51.4% SL in females or juveniles.

Coloration. Ocular side of body uniformly darkish brown mottled with numerous dark spots and rings of various size; a diffuse dark blotch above junction of curved and straight sections of lateral line; a darker and larger blotch on middle of straight section of lateral line; smaller blotch anterior of caudal peduncle; a series of dark botches along bases of dorsal and anal fins; pectoral fin on ocular side with brownish spots and irregular dark brown cross-bars. Blind side of body yellowish white.

Size. Reaching 170 mm SL in Taiwan; up to about 300 mm SL elsewhere ( Amaoka, 2016); a doubtful record of 45 cm TL in Hensley & Amaoka (2001).

Distribution. Around Taiwan, including Penghu, Green, Orchid and Dongsha islands; widely distributed in the tropical and subtropical waters of the Indian and Pacific oceans ( Amaoka, 2016).

Remarks. This species is sometimes confused with B. mancus that inhabits in a similar habitat, but it differs from the latter in having a smooth head margin without concavity and fewer fin rays, gill rakers and vertebrae.

Specimens larger than 100 mm SL, exhibit a distinct sexual dimorphism in the pectoral-fin length on the ocular side, presence of rostral and orbital spines, and orbital tentacles hind margins of both eyes. It is notable that many specimens do not show a clear sexual dimorphism in the interorbital width and the length of the pectoral fin on the ocular side. This is probably related to intersexuality observed by Amaoka et al. (1974), and which suggests the occurrence of sexual reversal.

Figures

FIGURE 3. A–B. Bothus mancus, NMMB-27812, female, 149.9 mm SL. C–F. B. myriaster, NMMB-P23231, male, 103.5 mm SL (C–D) and female, 107.6 mm SL (E–F). G–H. Bothus pantherinus, NMMB-P23285, male, 116.5 mm SL. Left column, ocular side and right column, blind side.