Age, Growth, and Spawning Period of Bamboo Sole Heteromycteris japonica in the Seto Inland Sea, Japan

Abstract

The bamboo sole Heteromycteris japonica is a small and dominant species found on sandy seabeds in south Japan. To examine the age, growth, and spawning period, juveniles and adults were collected with sledge-nets and beam trawl-nets, respectively, in the Seto Inland Sea, Japan. This species spawned from May to June, as suggested by the high gonadal somatic index in May and June and by the occurrence of newly settled juveniles [<10 mm in total length (TL)] from June to July. Using otolith sectioning and etching methods, the annual formation of opaque zones in sagittally sectioned otoliths was confirmed. The ages of fish between 76 and 158 mm in TL were determined, and the von Bertalanffy growth equations based on age-length relationships were derived for male and female H. japonica. The maximum ages encountered were 9 years for males and 11 years for females.