/ 046-072

A giant mottled eel, Anguilla marmorata Quoy and Gaimard, 1824 (Anguilliformes: Anguillidae), from a small urban river in Shizuoka Prefecture, central Japan

Kazuya Nagasawa, Takuya Sato and Kohei Sasagawa

Abstract / Introduction / Summary:

A giant mottled eel, Anguilla marmorata Quoy and Gaimard, 1824, was collected in a small river in an urban area of Shizuoka City, a capital of Shizuoka Prefecture, central Japan. The eel was about 140 cm in total length. In Japan, the species has been collected in fresh and brackish waters in the subtropical and temperate regions influenced by a warm current, the Kuroshio. This current flows in the western North Pacific Ocean off the coast of Shizuoka Prefecture, and the eel caught is considered to have migrated from the ocean to the river as a juvenile and to have survived and grown there because the river maintains warm water temperatures by receiving the drainage from the urban area including a nearby factory throughout the year. Freshwater fishes and crustaceans were abundantly found in the river and were most probably preyed on by the eel.