Abstract
A new estuarine moray eel, Uropterygiushades sp. nov., is described based on 14 specimens from Japan, Taiwan, the Philippines, southern Indonesia, and Fiji. It is a small-bodied, slender, uniformly dark-brown moray separated from congeners within the U.concolor species complex. The new species can be distinguished from congeners by the anteriorly positioned small eyes (5.0-7.2% of head length), absence of branchial pores, and extended inner rows of teeth which reach the posterior end of the jaws. Uropterygiushades sp. nov. represents a rare species of moray eel that inhabits turbid estuarine environments, preferring soft, muddy substrates, and burrowing and hiding among rocks or in fallen mangrove leaves. Additionally, Uropterygiusmactanensis Huang, Balisco, Evacitas & Liao, another species recently separated from the U.concolor species complex, is reported for the first time from Iriomote Island in the Ryukyu Archipelago based on two specimens; this new record expands the geographic range of U.mactanensis from the central Philippines to southern Japan.