Abstract / Introduction / Summary:
Two female specimens of argulid branchiuran were found in the collection of the Lake Biwa Museum, Kusatsu, Shiga Prefecture, central Japan. These specimens were collected in Matsunoike Pond within the Expo’70 Commemorative Park in Suita, Osaka Prefecture, central Japan, on 17 October 1987. Although they were found in bad condition, they have a single plumose seta on the posterior margin of the coxa of the first pair of legs and 47–50 supporting rods in the sucker membranes of the first maxillae. Based on these characters, they are identified as Argulus japonicus Thiele, 1900. There is no information on their fish host. This represents the second record for A. japonicus from Osaka Prefecture.