Lepidocephalus Bleeker 1858

Deein, Gridsada, Tangjitjaroen, Weerapongse & Page, Lawrence M., 2014, A revision of the spirit loaches, genus Lepidocephalus (Cypriniformes, Cobitidae), Zootaxa 3779 (3), pp. 341-352 : 342

Lepidocephalus Bleeker 1858

Lepidocephalus Bleeker 1858:303 . Type species: Cobitis macrochir Bleeker, 1854 designated by Bleeker 1863a:38 and 1863b:4.

Diagnosis. Cobitid with lateral line complete; dorsal-fin origin over or behind pelvic-fin origin; deep, slab-sided body; scales on top of head (except L. pahangensis ), cheek and opercle; eye very small and subcutaneous, or absent; 8–9 branched dorsal-fin rays; 9–13 pectoral-fin rays; 6–8 pelvic-fin rays; 42–43 vertebrae; lamina circularis a thickend 2 nd ray of pectoral fin on mature male.

Most often confused with Lepidocephalichthys and Pangio . Lepidocephalus differs from Lepidocephalichthys in having complete lateral line (vs. no lateral line); eye very small and subcutaneous, or absent (vs. eye present, not conspicuously small); 8–9 (vs. 6) branched dorsal-fin rays; 9–13 (vs. 7) pectoral-fin rays; longer predorsal length, (>60% SL vs. ~50–55%); and lamina circularis of mature male on 2 nd ray (vs. 7 th and 8 th rays) of pectoral fin (Havird et al. 2010). They also differ in numbers of total vertebrae (among species for which data are available) with Lepidocephalus having 42–43, and Lepidocephalichthys having 35–38 ( Roberts 1989:96). All species of Lepidocephalus except L. pahangensis , have scales on top of head (vs. scales absent on top of head in Lepidocephalichthys except in L. kranos and L. irrorata ), and on the cheek and opercle (vs. scales usually absent or deeply embedded on cheek and opercle in Lepidocephalichthys ).

Lepidocephalus differs from Pangio in having scales on cheek and opercle (vs. no scales on head); complete lateral line (vs. no lateral line); eye very small and subcutaneous, or absent (vs. eye present, not so conspicuously small); 8–9 (vs. 5–6) branched dorsal-fin rays; and 6–8 (vs. 5–7) pelvic-fin rays (Havird et al. 2010). Lepidocephalus has 42–43 total vertebrae (among species for which data are available), and Pangio has 45–71 total vertebrae ( Roberts 1989:96, as species of Acantophthalmus ).

In general appearance, Lepidocephalus is deep-bodied and slab-sided, and is readily distinguishable from Lepidocephalichthys , which is more slender and much less slab-sided, and Pangio , which is long, slender and generally eel-like in appearance.

Based on nuclear gene data, Šlechtová et al. (2008) hypothesized Lepidocephalus to be closely related to Canthophrys gongata (Hamilton 1822) , a species native to India, Nepal, Burma, Bangadesh and Pakistan ( Shrestha, 2008; Talwar and Jhingran, 1991). However, there is no morphological evidence to suggest a close relationship between Lepidocephalus and Canthophrys . Species of Lepidocephalus differ greatly from Canthophrys gongata in general appearance, and lack the pattern of black dorsal saddles and black spots on the side of the body and the wide depressed head with large upwardly directed eyes. They also differ in having the lamina circularis on the 2 nd ray (vs. medial rays) of the pectoral fin, and in having (vs. lacking) scales on the head.