Dicotylichthys Kaup, 1855

Leis, Jeffrey M., 2006, Nomenclature and distribution of the species of the porcupinefish family Diodontidae (Pisces, Teleostei), Memoirs of Museum Victoria 63 (1), pp. 77-90 : 85

Dicotylichthys Kaup, 1855

Dicotlylichthys Kaup, 1855 (type species Dicotylichthys punctulatus Kaup )

Atopomycterus Bleeker (ex Verreaux), 1865 [type species Atopomycterus diversispinus Bleeker (ex Verreaux)]

Diagnosis. Spines on head and belly erectile, those on back and sides fixed; fixed spines with 3 bases, erectile spines with 2 bases; spines long to medium; 9 C rays; 21 vertebrae; no tentacles; nostril in adult bifid; no spines wholly on dorsal surface of caudal peduncle, but large spines extend over the peduncle nearly to the caudal-fin base; no fins spotted; no large blotches on dorsal surface, but lateral bars present. Some additional osteological characters are given by Tyler (1980, ref. 4477).

The type species of Dicotylichthys is D. punctulatus Kaup (1855, ref. 2571). The sole species in this genus has erectile spines on the head and belly, but fixed ones on the back and sides. In contrast to the arrangement adopted here, some authors follow Fraser-Brunner (1943, ref. 1495) and include all diodontids that develop bifid nasal organs in Dicotylichthys . This would place in the same genus such disparate species as pilatus with all fixed spines, punctulatus with a mixture of erectile and fixed spines, and nicthemerus with all erectile spines. However, Dicotylichthys is very similar to the monotypic Lophodiodon (see below). Bleekerʼs (1865, ref. 416) description of Atopomycterus (based on an unpublished manuscript by Verreaux held in MNHN) is brief, but fortunately the types of A. diversispinus Bleeker are extant (see below), thus clearly showing that Atopomycterus is a synonym of Dicotylichthys .