Anguillid Leptocephali from the Waters South of Okinawa and East of Taiwan and Luzon, Western North Pacific, in 1986

A total of 27 specimens of the anguillid leptocephali were collected by the R. V. Hakuho Maru, Ocean Research Institute, University of Tokyo, in the waters south of Okinawa and east of Taiwan and Luzon in September 1986. These leptocephali were identified as 21 Anguillia japonica Temminck et Schlegel, one A. bicolor pacifica Schmidt, and five A. marmorata Quoy et Gaimard and/or A. celebesensis Kaup based on the segmental characters. The present A. japonica leptocephali were 33.9-47.0 (mean 43.1) mm TL, and were smaller than those of the previous collections. The location and month of the capture extended spatially and temporally the distribution of the Japanese eel leptocephali in the sea. The smallest specimen (33.9 mm TL) in the present A. japonica leptocephali, the youngest larva hitherto known from the field, was collected in the waters east of Luzon. All the leptocephali of other Anguilla species were found in the waters south of 17°N except one specimen.