Improved larviculture of ocellate puffer Takifugu rubripes through control of stocking density

The occurrence of cannibalism in larviculture of ocellate puffer is affected by initial stocking density and lower initial stocking density can suppress the occurrence of its cannibalism. However puffer larvae begin cannibalism sooner or later. To reduce mortality due to cannibalism, we investigated the effect of re-stocking at reduced densities. Ocellate puffer larvae were reared at an initial stocking density of 5 larvae l− 1 in six 1-m3 tanks from 0 to 21 days after hatching (DAH). They were then re-stocked at four different densities of 1 to 4 larvae l− 1 in duplicate and reared until 40 DAH. On 21 DAH, the average number of survivors was ~ 4300 larvae. After re-stocking, the survival rate was negatively correlated with re-stocking density (R = − 0.936, P < 0.01). The number of surviving ocellate puffer larvae was highest at a re-stocking density of 2 larvae l− 1. A reduction in stocking density at 21 DAH is recommended for an improved larvicultural performance of the ocellate puffer.