• Korean Journal of Ichthyology
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• v.36 no.3
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• pp.263-272
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• 2024

The genus Rhinogobius fishes, collected from a stream in the Geumodo Island of Yeosusi, Jeollanam-do, Korea, were identified as Rhinogobius nagoyae Jordan and Seale, 1906. The specimen from Geumodo Island exhibited the following morphological characteristics, which were consistent with the original description of R. nagoyae and other literatures: I, 7~8 second dorsal fin rays; I, 7~8 anal fin rays; 18~19 pectoral fin rays; 31~36 longitudinal scales; 8~9 transverse scales; first dorsal fin elongate in male, its distal tip reaching to base of second or third branched ray of second dorsal fin in males when adpressed; pectoral fin base with 1~3 crescent-like reddish brown line; abdomen blue when mature; when alive or freshly-collected, cheek with vermiculate reddish brown line; caudal fin 6~7 distinct rows of dark dots; a bow-shaped dark brown blotches at caudal-fin base. Detailed specimen-based descriptions were reported here.

• Animal Systematics, Evolution and Diversity
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• v.12 no.4
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• pp.331-347
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• 1996

The geographic distribution and variation for Rhinogobius brunneus were surveyed by means of allozymic and morphological analyses and it was revealed that the Korean populations of R. brunneus comprise three distinct types, Type-A, Type-B, and Type-C, which show considerable differentiation to a degree of interspecific level(Rogers' S(1972): $S_{A-B}$=0.631, $S_{A-C}$=0.628, $S_{B-C}$=0.661). In addition, no evidence of gene flow among the types was found at sympatric area and it is assumed that reproductive isolation is completed. Moreover there is microhabitat segregation according to the distance from river mouth among each types and which segregation was regarded as a factor to facilitate reproductive isolating mechanism. Therefore, based on the evidence presented above, these three types of R. brunneus are considered as typical discrete species.