Freshwater gobies of the genus Stiphodon from Japan andTaiwan (Teleostei: Gobiidae: Sicydiini)

Three species of the freshwater goby genus Stiphodon (Sicydiini) recognized from Japan and Tai wan, are compared in text and tabular information. Stiphodon atropurpureus (Herre, 1927) is rediag nosed. Common in the Philippines, it is rare in Japan and Taiwan. It is distinguished in usually having 15 pec toral rays, 9 segmented second dorsal fin rays, and 3033 lateral scales. Males are distinguished from other species in having a patch of white fatty tissue posterior to lower base of pectoral fin, first dorsal fin spines not elongate or filamentous, body and head grayish in preservation, in life with a bright metallic green stripe above the midline turning bright blue after death. Females with a zigzag-like midlateral stripe and never with fatty tissue posterior to pectoral base. Stiphodon imperiorientis sp. n. , is a rare species known from 10 specimens from Iriomote Island, Ryukyu Islands, and has 15 (15-16) pectoral rays, 9 segmented second dorsal fin rays, and 35-36 (34-36) lateral scales. It is distinguished in males always being without white fatty tissue posterior to lower base of pec toral fin, spines 4 and 5 elongate in first dorsal fin, in preservation body and head mostly tannish or brownish with dusky bars on trunk and caudal peduncle, in life head bright blue, laterally blue between dusky bars. Female with midlateral stripe appearing mostly straight with blotches present ventral to second dorsal and on caudal peduncle. Stiphodon percnopterygionus sp. n. , is a fairly com mon species in the islands of Iriomote and Ishigaki, Ryukyu Islands, Japan and eastern Taiwan, but very rare in Micronesia. It is distinguished by usually having 14 pectoral rays and 10 segmented second dorsal fin rays. Males are unusual in having two distinctive colour phases, young males mostly blue and older males mostly orange: colour phases are associated with size and not geographical distribution.