Argulus japonicus (Branchiura: Argulidae) parasitic on largemouth bass Micropterus salmoides in Japan, with the morphology of the adult female of the argulid

Abstract

Largemouth bass Micropterus salmoides (Lacepède, 1802) was introduced from North America into Japan in 1925 and 1972. The fish has spread extensively since the late 1960s and is now found in all prefectures of Japan. An adult female of the argulid branchiuran Argulus japonicus Thiele, 1900 was collected from the body surface of a largemouth bass in the Kako River, Hyogo Prefecture, Japan. This represents a new host record for A. japonicus. The morphology of the adult female collected is reported in detail. Although A. japonicus is native to Japan, the species is not strictly host-specific and can utilize largemouth bass of the North American origin as its host in Japan.