Genus Flabellicauda

Diagnostic characters:  snout moderate in length and slightly pointed, not extremely long or strongly rounded; oral cleft very small, restricted to anterior tip of snout, posterior portion of both jaws covered by thick skin of snout; gill opening a tiny, narrow slit, dorsal-most point level with base of 9th to 14th (usually 12th, rarely 9th) pectoral-fin ray in lateral view; gill membrane attached to isthmus; two rows of gill filaments on gill arches 1–3; extremely small ‘single’ adhesive disc, its length 8.1–13.5% SL; center of disc flat, without cavity; disc papillae flattened, similar in size across disc surface; preopercular lateral-line canal and associated pores absent; dorsal, anal, and caudal fins connected via thin membrane, giving appearance of single, continuous median fin around posterior part of body; and upper and lower hypural plates completely fused, forming large fan-like hypural complex.