Bull. Jpn. Soc. Fish. Oceanogr. 72(2), Page 83-91, 2008   Distribution of larvae of Parapristipoma trilineatum (Haemulidae) in Tosa Bay, Japan Jun-ichi Nunobe1†, Izumi Kinoshita1, Minoru Sashida1 and Osamu Murata2 1 Usa Institute of Marine Biology, Kochi University, Usa, Tosa, Kochi 781-1164, Japan 2 Fisheries Laboratory, Kinki University, Shirahama, Wakayama 649-2211, Japan † e-mail: jun55829@yahoo.co.jp The distribution of Parapristipoma trilineatum larvae was examined using a larva net (mesh aperture=0.5 mm, mouth diameter=1.3 m) and shirasu trawl (mesh size of bag-net=2 mm) collections between January and December 2002. A total of 244 (primarily preflexion stage of 1.7-5.7 mm in body length and 2-14 days old) and 1,285 larvae (primarily postflexion stage of 4.1-10.1 mm BL and 10-22 days old) occurred near the coast and offshore from May to August and from May to July with peaks in June and July, respectively. Monthly occurrence of larvae and their hatching dates estimated from daily rings of otoliths revealed that P. trilineatum spawn from early May to late July with a peak in June. This spawning period corresponds approximately with that of neighboring prefectures where water temperatures are relatively warmer. Considering horizontal dispersal in the early stages (preflexion to flexion), the larvae tended to immigrate to shallow waters such as shirasu fishery grounds just after attaining to the postflexion stage. Key words: Parapristipoma trilineatum, larva, horizontal distribution, morphology, daily age, spawning season, early migration