Second record of Bathygobius panayensis (Gobiidae) based on Japanese specimen, with notes on its diagnostic characters

A single specimen of Bathygobius panayensis (Jordan and Seale, 1907) (37.8 mm in standard length), a poorly known gobiid species, was collected from Kadogawa Bay (32°28′37.90′′N, 131°39′59.26′′E), northern Miyazaki Prefecture, Kyushu, Japan in September 2022. The species is known only from the holotype from Panay Island, Philippines. Thus, the present specimen from Japan is the second record of the species and remarkably updates a distribution range. The present study provided detailed description and color images of the Japanese specimen, revealing that the following diagnostic characters to distinguish B. panayensis from other congeners: second dorsal-fin rays I, 10; anal -fin rays I, 8; pectoral-fin rays 19 or 20 with uppermost four rays free and bifurcated; longitudinal scale rows 40 or 41; transverse scale rows 13 or 14; predorsal scales undeveloped (if present, a single cycloid scale embedded under mucus layer); white spots longitudinally present along body axis; reddish-brown spots scattered on dorsal/caudal fins and dorsal surface of body. The new standard Japanese name “Bozu-kumo-haze” was proposed for the species referring one of the distinctive characters (almost no scales on head and predorsal region).