Melanotaenia multiradiata
Moswaren Rainbowfish
Species Summary
Melanotaenia multiradiata is one of three closely related rainbowfishes from the Birds Head Peninsula of West Papua, Indonesia, described together in 2014, and reaches the largest size of the trio (the 122.5 mm SL holotype is the largest type specimen among them). Like M. ericrobertsi, it was originally confused with M. irianjaya before genetic and colour evidence showed it to be distinct.
Etymology
The species name multiradiata combines the Latin multi-, many, and radiata, rayed, referring to its relatively high number of pectoral-fin rays (15 or more in 91.3% of specimens) compared with other Ayamaru-complex species.
Etymology compiled from C. Scharpf (2023), “Fishes of Sahul: An Etymological Survey (Part 6), the rainbowfishes (continued)”, Fishes of Sahul 37(1): 2006–2022, and etyfish.org.
Distribution & Habitat
Melanotaenia multiradiata is known only from Sisiah Creek near Moswaren village, about 25 km east of Teminabuan on the Birds Head’s south coast. The type locality, at about 86 m elevation and roughly 58 km upstream from Waromge Bay, is a substantial stream 15–20 m wide and up to 2 m deep, with slow to moderate flow over a limestone-rock bottom; fish were concentrated around log debris in the deeper sections, and the water was exceptionally clear, with underwater visibility estimated at 20 m.
Description & Comparison with Similar Species
Live males are bluish green above, grading to whitish below, with a dark blue to blackish mid-lateral stripe that is faint and narrow on the front two-thirds of the body but bold and up to three scales wide on the rear body and caudal peduncle — a feature shared with M. ericrobertsi. The dorsal fins are reddish with a bold dark submarginal stripe and broad white outer margin, and the caudal fin has a distinct white posterior margin, unique among its Birds Head relatives. Beyond its exceptionally high pectoral-ray count, Melanotaenia multiradiata belongs to the same Ayamaru-complex group as M. ajamaruensis, M. boesemani, M. ericrobertsi and M. laticlavia, sharing their characteristic dark submarginal dorsal-fin stripe and pale outer margin.
Account compiled for Home of the Rainbowfish from G. R. Allen, P. J. Unmack & R. K. Hadiaty (2014), “Three new species of Rainbowfishes (Melanotaeniidae) from the Birds Head Peninsula, West Papua Province, Indonesia”, aqua, International Journal of Ichthyology, 20(3): 139–158.
References
- Allen G.R., P.J. Unmack & R.K. Hadiaty (2014) Three new species of Rainbowfishes (Melanotaeniidae) from the Birds Head Peninsula, West Papua Province, Indonesia. aqua, International Journal of Ichthyology, 20(3): 139-158.