A New Species of Manonichthys Gill, 2004 (Pisces: Pseudochromidae) from Irian Jaya Barat Province, Indonesia

11 specimens, 13.3-58.4 mm standard length (SL), collected in the Fak Fak Peninsula region of Irian Jaya Barat Province (western New Guinea), Indonesia. It was observed on coral reefs at depths of 9-16 m and was occasionally seen entering sponges of the genus Callyspongia. It apparently mimics Chromis retrofasciata Weber, 1913, a small pomacentrid fish that exhibits a similar color pattern. The new taxon is most similar to M. alleni, M. polynemus, and M. splendens from the Indo-Malay Archipelago, but is distinguished from those species and all other pseudochromines on the basis of the color pattern, particularly the presence of a prominent black bar across the anterior caudal peduncle and adjacent posterior body extending onto the basal 1/2 of the last 6-8 dorsal and anal fin rays. Additionally, adults have fewer predorsal scales than M. polynemus (20-24 vs. 25-30) and a different caudal-fin shape than M. alleni and M. splendens (emarginate rather than rounded to truncate)