Grammatobothus Norman, 1926

Amaoka, Kunio & Ho, Hsuan-Ching, 2019, The lefteye flounder family Bothidae (Order Pleuronectiformes) of Taiwan, Zootaxa 4702 (1), pp. 155-215 : 188

Genus Grammatobothus Norman, 1926

Grammatobothus Norman, 1926:253 . Type species: Platophrys polyophthalmus Bleeker, 1865 .

Diagnostic features. Body ovoid, compressed. Tip of isthmus below middle of lower eye. Dorsal profile of head similar in both sexes and growth. Both eyes separated by a narrow concave space. Sexual dimorphism in lengths of dorsal-fin rays and pectoral-fin rays. Interorbital width stable with sex and growth. No rostral, orbital and mandibular spines.

Mouth rather small; maxilla extending to or slightly beyond anterior margin of lower eye. Teeth small, uniserial on both jaws, not enlarged anteriorly. Gill rakers short and smooth.

Scales small, not deciduous, ctenoid on ocular side with short ctenii along posterior margin; scales cycloid on blind side. Lateral line on ocular side curved above pectoral fin, obscure lateral line present on blind side.

Dorsal and anal fins without branched rays; 2nd to 10th rays of dorsal fin elongate in both sexes, but longer in males than in females. Pectoral fin on ocular side elongate with filamentous rays in males. Pelvic fin on ocular side starting at tip of isthmus; first ray on blind side opposite to third or fourth fin ray on ocular side. Caudal skeleton with four plates including parhypural and three hypurals, without deep clefts.

Remarks. Grammatobothus closely resembles Bothus in body shape, but differs in having a narrow interorbital width without sexual difference, elongate anterior dorsal-fin rays, three suborbital bones on blind side, abdominal vertebrae not expanded, and first interhaemal spine not enlarged.