人工催熟による養成クルマエビの効率的な採卵条件

Abstract

Efficient spawning conditions through artificially induced maturation by unilateral eyestalk ablation were investigated for the kuruma prawn Marsupenaeus japonicus. After unilateral eyestalk ablation, 24℃ was the most efficient water temperature for spawning (rate, number of spawning times, and number of eggs) in the comparison of four water temperatures (20, 22, 24, and 26℃). Egg diameter tended to increase with decreasing water temperature. As a result of unilateral eyestalk ablation at different molting stages, the postmolt stage was better in spawning rate and survival until spawning. Based on these results, individuals that seemed to be in the postmolt stage were selected manually, subjected to eyestalk ablation, and reared at 24℃. Prawns were randomly split into two feeding groups of compound feed or live polychaete. Unilateral eyestalk ablation enabled spawning of the group consuming the compound feed. For both feeding groups, most individuals spawned on Day 10.