Illustrated checklist of fishes from the Shubuto River System, southwestern Hokkaido, Japan

Abstract

A checklist of fish fauna, comprising 40 species representing 15 families and 9 orders, was compiled from field, museum, and literature surveys of the Shubuto River System, southwestern Hokkaido, Japan. This area approximates the boundary of southern/northern affinities of Japanese freshwater fishes. All primary freshwater species, are listed except for Gymnogobius castaneus and all anadromous and marine amphidromous species that are scientifically presumed to occur naturally in the area. The list contains two invasive exotic species, Cyprinus carpio and Oncorhynchus mykiss, and two Siberian primary freshwater species, Lefua nikkonis and Barbatula toni, which are thought to mark the boundary of southern and northern affinities of Japanese freshwater fishes. Rhynchocypris perenurus, another Siberian primary freshwater species with a similar presumed range, was not recorded. The voucher specimen species included Platycephalus sp. 2, which is suggested to have the northernmost extended range.