A RARE RIBBON-GOBY OXYMETOPON CYANOCTENOSUM (ACTINOPTERYGII: PERCIFORMES: GOBIOIDEI: MICRODESMIDAE): THE FIRST AND NORTHERNMOST RECORD FROM TAIWAN

Species of the genus Oxymetopon (Gobioidei: Microdesmidae) have never been recorded from Taiwanese waters. The main objective of this paper is to document the presence of this genus in the waters of Taiwan. A single specimen (99.2 mm standard length) of genus Oxymetopon was collected from south-western Taiwan in 2017. The morphology and fresh coloration of the collected specimen are herein described. The majority of the morphological characters of the specimen closely matched the diagnostic features of Oxymetopon cyanoctenosum Klausewitz et Conde, 1981 given by the previous study: ray in first dorsal-fin not elongated, tip of depressed rays just reach origin of second dorsal-fin origin; longest first dorsal-fin length shorter than body depth; dorsal crest high, approximately half of the diameter of pupil; tip of depressed pelvic fin reach to analfin origin; pelvic-fin length longer than pectoral-fin length. Therefore, the specimen from south-western Taiwan is identified as Oxymetopon cyanoctenosum. This species has previously been known only from Philippines, Indonesia, and Papua New Guinea. The presently reported specimen represents the first record for Taiwan, as well as the northernmost record of this species up to now.