Description

SINGLE PAPER

Volume 10, Issue 1 – June 2005

Hiroyuki Motomura, Shigeru Harazaki and Graham S. Hardy: A new species of triplefin (Perciformes: Tripterygiidae), Enneapterygius senoui, from Japan with a discussion of its in situ colour pattern, pp. 5-14

Abstract

Enneapterygius senoui, a new species of small triplefin, is described on the basis of six specimens collected from Hachijo-jima Island, the Izu Islands and Chichi-jima Island, Ogasawara Islands, Japan. This species is distinguished from other congeners by the following combination of characters: 14 or 15 (mode 15) second dorsal fin spines; 20 or 21 (21) pored lateral line scales; 17-19 (17) notched lateral line scales; 2 or 3 (2) scale rows above first pored lateral line scale; 2 or 2 1/2 (2 1/2) scale rows above last pored lateral line scale; 3 or 4 (3) scale rows below first notched lateral line scale; 4-5 + 1-2 + 4-5 mandibular pores; nasal tentacle unbranched flat, broad distally; a broad vertical white band on caudal peduncle behind third dorsal fin, and blue lines or spots on head in both sexes; anterior two-thirds of body and fins black, and posterior tip of anal fin yellow in melanistic males; reddish spots on head and body, and anal fin yellow basally in pale males and females. The species is further confirmed from Izu-oshima Island and the east coast of Izu Peninsula on the basis of underwater photographs. In situ colour pattern and variations are also described and discussed.