Reproductive biology of nocturnal reef fish Pempheris sp. (Pempherididae) in Okinawa Island, Japan

Reproductive characteristics of Pempheris sp. were studied in 233 specimens collected from May 2006 to October 2010 on Okinawa Island, Japan. The main spawning season was estimated during April to June, but spawning occurred year round. Standard length at first maturity occurred at ca. 110 mm in both sexes. Batch fe­ cundity of Pempheris sp. was ca. 2,000-19,000 per female, and was higher in the main spawning season than in other seasons. No relationship between spawning and lunar periodicity was observed. The spawning interval of Pem­ pheris sp. was estimated to be ca. 2 days, with spawn ing occurring shortly after sunset.