短蛸幼体同类相残行为的观察

Observation on the Cannibalistic Behavior among Octopus ocellatus Larvae

在不同条件下,对短蛸幼体(平均体重0.03～0.66 g)进行同类相残研究。结果表明:①相同规格的小规格幼体较大规格幼体日相残率高,相残最严重的时期是在平均体重0.03～0.08 g阶段,当平均体重0.23 g以上时,相残行为较弱,当平均体重0.66 g时,幼体基本不再相残。②放养密度高低、饵料是否适口和有无遮蔽物对日相残率影响显著。③温度对短蛸幼体的相残行为有影响。④幼体间个体大小存在差异,尤其是小规格幼体间出现个体大小差异时,小个体更易受到攻击,相残行为严重。基于以上研究结果,饵料不适口和无遮蔽物是导致短蛸幼体发生同类相残的主要原因,高密度养殖、养殖温度高和个体大小的差异会诱发和促进同类相残的发生。

The study was focused on the cannibalism among Octopus ocellatus larvae（average weight 0.03 0.77g）with different environmental treatments.The results showed that：①To the same size larvae,the small ones was higher than the big ones on daily cannibal rate.The period which was the most serious cannibalism was at average weight 0.030.08g,daily cannibal rate was much lower when the average weight came over 0.23 g,and no cannibalistic behavior was found when its average weight was more than 0.66 g.②The daily cannibal rate was markedly influenced by the stocking density,diet and hidden material.③The temperature alse affected the cannibalism.④Differences in body sizes might lead to serious cannibalism especially among small sized larvae,smaller individuals were susceptible to be attacked by larger ones.Based on these observations above,unfitted eaten diet and no hidden material for larvae were considered to be the significant factors affecting cannibalism during the larval period;high stocking density,and high culturing temperature as well as differences in body size could induce and stimulate the cannibalism.