Parabothus Norman, 1931

Amaoka, Kunio & Ho, Hsuan-Ching, 2019, The lefteye flounder family Bothidae (Order Pleuronectiformes) of Taiwan, Zootaxa 4702 (1), pp. 155-215 : 197-198

Genus Parabothus Norman, 1931

Parabothus Norman, 1931b:600 . Type species: Arnoglossus polylepis Alcock, 1889 .

Diagnostic features. Body elliptical. Tip of isthmus below or slightly behind posterior margin of lower eye. Sexual dimorphism and ontogenetic changes of head profile, head spines and interorbital width. Front margin of head steeper in mature males than females and juveniles. Both eyes separated by wide concave space; interorbital width larger in males than in females and juveniles. Usually no rostral, orbital and mandibular spines in both sexes, except for occasional short obtuse rostral and mandibular spines in males.

Mouth large; maxilla extending to anterior margin of lower eye or somewhat beyond. Teeth on both jaws usually uniserial, rarely biserial in upper jaw; teeth slightly enlarged anteriorly. Gill rakers moderately long, usually not serrated, absent on upper limb.

Scales rather not deciduous, ctenoid on ocular side with row of moderately long ctenii along posterior margin; scales cycloid on blind side. Lateral line on ocular side curved above pectoral fin; lateral line absent on blind side. Dorsal and anal fins with simple rays. Pectoral fin on ocular side not elongated in both sexes. Pelvic fin starting at tip of isthmus; first ray on blind side opposite to third or fourth ray on ocular side. Vent on blind side, just in front of origin of anal fin, and urogenital pore on ocular side. Caudal skeleton with four plates, including parhypural and three hypurals; no deep clefts on distal margin.

Remarks. Parabothus closely resembles Tosarhombus in having ctenoid scales on the ocular side bearing moderately long spines, caudal plates lacking clefts, and sexual dimorphism of the interorbital width. It differs from Tosarhombus in having a narrower interorbital space, usually absence of a rostral spine in male, a more elongate body, and the anterior head margin lacking clear blotches.