Reproductive habitat use, body-size structure and spawning season of Cobitis minamorii minamorii in paddy fields and ditches

We surveyed the reproductive ecology of Cobitis minamorii minamorii in paddy fields and ditches. The spatial distribution of females in the spawning season differed from that in the non-spawning season, even in short ditches. Eggs were collected in both ditches and paddy fields, unlike an earlier study demonstrating that no eggs were collected in ditches. The frequency distributions of standard body lengths of males and females were unimodal and bimodal, respectively. The females with a large standard body length were expected to be gravid with higher probability in May.