Rediagnosis of the monotypic genus Lepadicyathus Prokofiev 2005 (Gobiesocidae: Diademichthyinae) and redescription of Lepadicyathus minor (Briggs 1955), new combination.

A revised diagnosis is provided for the poorly known clingfish genus Lepadicyathus Prokofiev 2005. The genus belongs to Diademichthyinae (sensu Conway et al.) and is characterized by the following combination of characters: snout moderate in length, slightly pointed in lateral view; oral cleft very small, restricted to anterior tip of snout, posterior portion of both jaws covered by thick skin; gill membrane attached to isthmus; gill opening tiny, narrow slit, dorsal-most extent level with base of 12th or 13th pectoral-fin ray in lateral view; "single" adhesive disc, its size moderate, length 16.6–20.4% SL; center of disc flat, without cavity; disc papillae flattened, similar in size across disc surface; cephalic lateral-line canals moderately developed, including 2 nasal, 2 lacrimal and 2 postorbital pores; pre-opercular and mandibular lateral-line canals absent; anus situated about midway between posterior margin of disc and anal-fin origin (disc to anus length 45.8–55.5% of disc to anal-fin origin length); dorsal, anal, and caudal fins weakly connected by membrane with distinct notch between fins; premaxillae separated anteriorly by large circular gap in dorsal view; nasal bone long, anterior tip pointed, terminating close to anteromedial tip of premaxilla in dorsal view; few lower-jaw teeth (ca. 6), restricted to anterior ca. 1/4 of dentary; basibranchial elements (including cartilages) absent; caudal skeleton with upper and lower hypural plates, separated by narrow hypural diastema. As recognized herein, Lepadicyathus is monotypic and contains only Lepadicyathus minor (Briggs 1955), new combination. The species has previously been assigned to Lepadichthys Waite 1904 and represents a senior synonym of Lepadicyathus mendeleevi Prokofiev 2005, type species of Lepadicyathus. [ABSTRACT FROM AUTHOR]