Asterropteryx atripes , a new gobiid fish from the Western Pacific Ocean (Perciformes: Gobioidei)

Abstract

A new gobiid fish, Asterropteryx atripes, is described on the basis of eight specimens from Iriomote-jima Island, Ryukyu Islands, and El Nido, Philippines. It differs from its congeners by having the following combination of characters: 3rd spine of first dorsal fin long, filamentous, distal tip usually over end of 2nd dorsal fin base when appressed in both sexes; pelvic fins almost separated, innermost (=5th) segmented rays connected by rudimentary low membrane between bases, and no frenum; 4–7 short spines on posterior margin of preopercle (the uppermost spine usually just behind the cephalic sensory canal pore N); eye large, 32.3–35.8% of head length; enlarged haemal arches on 1st two caudal vertebrae; a distinct black band from posterior margin of eye to caudal fin base (indistinct in dark-phase individuals); black pelvic fin (vivid in dark-phase individuals); numerous minute bright blue spots on head and body in life; no distinct dark spots on head and body; iris entirely reddish-brown or dusky (bright white ventrally in pale-phase individuals) when alive or fresh, and entirely black in preservation, without white transverse bar on middorsal surface; hovering habit. The new species appears to be most closely related with the other only known hovering species, A. striata; the latter is readily distinguished from the former in having no long, filamentous dorsal spine; semitranslucent pelvic fin; and a series of small black spots along dorsal fin base and dorsal edge of caudal peduncle. Asterropteryx contains two distinct groups, and the monophyly of the genus is open to question.