Threadless cheek-hook goby (Ancistrogobius yoshigoui)

Biology

Dorsal spines (total): 7; Dorsal soft rays (total): 9-10; Anal spines: 1; Anal soft rays: 9. This species is unique from its congeners by having the following characters: lacks a filamentous spine on the first dorsal fin (the third spine subequal in length to preceding spine); 19-20, typically 20 pectoral-fin rays; head and most of nape no scales, predorsal scales absent; pelvic fins fused medially with well developed connecting membrane and frenum; fifth segmented ray of pelvic fin 91.8-94.9% of preceding ray in length; below the eye faint, dusky blotches (not forming vertical bar); distal tip of first dorsal fin with a black blotch, wide, extending posteriorly to middle or more posterior part of third interspinal membrane; sensory papilla rows x^1 and x^2 not continuous, interrupted by row trp; sensory papilla rows trp extending dorsally to slightly above a longitudinal line through rows x^1 + x^2; anterior tip of sensory papilla row b extending or not to row 4 and w

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