Double-fin cheek-hook goby (Ancistrogobius dipus)

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: largely separated pelvic fin with rudimentary connecting membrane and no frenum; fifth segmented ray of pelvic fin short, length 67.9-71.9% of preceding ray; a narrow black blotch on distal tip of first dorsal fin (not reaching posteriorly to third spine); pectoral-fin rays 19-21, usually 20; head and most of nape naked, no predorsal scales (except for one specimen, WAM-P.32537-001, with one predorsal scale); third spine of first dorsal fin greatly elongated, filamentous, obviously longer than preceding spine, typically with alternating pale and dusky (or yellow) bands when alive or fresh; faint, dusky blotches (not forming distinct vertical bar) below eye; sensory papilla x^1 and x^2 not continuous, interrupted by row trp; sensory papilla rows trp long, extending dorsally to well above a longitudina

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