Spawning season and size at sexual maturity of Kyphosus bigibbus (Kyphosidae) from northwest Kyushu, Japan

The reproductive characteristics of Kyphosus bigibbus were examined using individuals collected between June 2004 and February 2009 off Nagasaki Peninsula in northwest Kyushu, Japan. The spawning season and size at sexual maturity of this species were characterized based on a gonad index and histological examination of the gonads. The spawning season extends from June to October. This species is assumed to be an indeterminate, multiple-batch spawner. Females reached sexual maturity at larger size than males (fork length at 50% sexual maturity: males 284 mm, females 360 mm).