Melanotaenia wanoma (∧ male ∨ female) © B. Dwisusilo

Melanotaenia wanoma

Species Summary
The colour of mature males is brownish on upper back; body scales with narrow brown outline; lower half of side of body and belly whitish; a diffuse dark blotch immediately behind eye on uppermost part of operculum; a golden patch in middle part of operculum; a broad and oblong blue blotch extending from just below pectoral-fin base to above middle of anal fin; 8 to 9 narrow orange stripes between each scale row; a dark midlateral stripe extending from upper edge of preopercle to caudal-fin base, the stripe more or less solid on rear half body and about 1.5 scale wide on caudal peduncle; pectoral fins translucent; pelvic fins orange; dorsal and anal fins brown with yellowish to orange tint between rays and marked with a prominent white margin stripe with reddish extremities. Overall colour of females is similar but paler than males with a narrow margin stripe on both second dorsal and anal fins.

Similar to many Melanotaenia, mature males have a tendency to be deeper bodied than females (30.8-32.8 vs. 28.7-31.7% SL) and have a more elongate and pointed shape posteriorly on the soft dorsal and anal fins. The longest soft dorsal-fin rays of males are located in the posteriormost portion of the fin, in contrast to that of females, which are situated in the anterior half of the fin. Depressed posterior tip of the dorsal fin extends the hypural junction for males and only the half of caudal peduncle length for the females. In addition, the depressed posterior tip of anal fin reaches half of caudal peduncle length for males and only one third for the females. The species is named wanoma, in reference to Wanoma village located some 16 km to the north in Arguni Bay.

Melanotaenia wanoma is related to the species occurring on the Bomberai Peninsula and on the Bird's Head Peninsula (Vogelkop or Doberai Peninsula) of far western New Guinea. The Bird's Head Peninsula forms the north-western end of the island of New Guinea. To the east is Cenderawasih Bay and to the south Bintuni Bay. To the west, across the Dampier Strait is Waigeo Island, and Batanta Island lies just off the northwest tip. The peninsula south is Bomberai Peninsula.

Distribution & Habitat
Melanotaenia wanoma is currently known only from the type locality, a karst resurgence emerging from the NE side of the Kaimana Anticline. Wermura Creek is also a short and fragmented hydrologic system like the Gebiasi Creek. Both creeks are only distant by 4 km but emerge from distinct geological fault. Wermura Creek emerges from a small cave then flows on about 200 m before disappearing in a subterranean outlet. The creek reappears after 1 km in the mangrove from a large cave, and flows to the Arguni Bay. The type locality (altitude 42 m) consists of a crystalline stream, narrow (to about 1 m wide), relatively shallow (up to about 1 m) and flowing in primary forest.

Remarks
Specimens of Melanotaenia wanoma were collected in November 2010 during the Lengguru-Kaimana Expedition led by Balai Riset Budidaya Ikan Hias in Depok, Indonesia (BRBIH-KKP), the Akademi Perikanan Sorong, Indonesia (APSOR-KKP), the Lembaga Ilmu Pengetahuan Indonesia (LIPI) and by the Institut de Recherche pour le Développement Montpellier, France (IRD).

Literature
Kadarusman, R.K. Hadiaty, G. Segura, G. Setiawibawa, D. Caruso & J. Pouyaud (2012) Four new species of Rainbowfishes (Melanotaeniidae) from Arguni Bay, West Papua, Indonesia / Quatre nouvelles espèces de poissons arc-en-ciel (Melanotaeniidae) de la baie d'Arguni en Papouasie occidentale, Indonésie. Cybium, 36(2): 369-382.

Adrian R. Tappin
July, 2012