Social organization,patterns of sexuality,and behavior of the wrasse Coris dorsomaculata at Miyake-jima,Japan

Synopsis The wrasse Coris dorsomaculata was investigated at Miyake jima, Japan. This species is sexually dichromatic and males arise from sex-changed females. Individuals were found living in harems which may be maintained through the defense of food by dominant males. The behavior of this species was similar to other studied wrasses, with the exception of a post-spawning display by males and the regular formation of multi-male aggregations in the late afternoon. Reproductive activity appeared to be affected by the warm-temperate climate at the study area. When day length was long, the spawning time coincided with outgoing tidal currents. When day length was short, the daily spawning time became fixed.