Effects of limb autotomy on growth, feeding and regeneration in the juvenile Eriocheir sinensis

• Effects of autotomy on the growth of Eriocheir sinensis were investigated.
• All injured crabs could feed and molt as normal crabs, and could manage to regenerate new limbs.
• The length of the 1st molting period negatively correlates with the number of autotomized limbs.
• After the 2nd molt, the size of new limb is the same as that of normal limb.
• The specific growth rate positively correlates with the number of autotomized limbs during the 1st molting period.

Eriocheir sinensis, as an emerging aquaculture species, has become more popular in Chinese pond culture. However, high density stocking has usually caused high limb autotomy rate among juvenile crabs, and there are still very few reports about the effects of autotomy on both survival and growth rates in the juvenile E. sinensis. Therefore, we aimed at the effects of limb autotomy on the growth of E. sinensis through the individual cultivation method. The results showed that almost all injured juvenile crabs could feed and molt as normal crabs, and could manage to regenerate new limbs. The duration of the 1st molt had a negative correlation with the number of autotomized limbs. After the 2nd molt, the size of the new limb was comparable to that of the normal limb and the weight growth rate decreased with the increasing number of autotomized limbs. However, a positive correlation was found between the specific growth rate and the number of autotomized limbs during the 1st molting period. In this period, the feeding rate decreased slightly, and the crabs with more limb loss tended to have the lower feeding rates, but this had no significant difference (P > 0.05). Besides, feed efficiencies in experimental sets were slightly higher than the control, and those crabs that autotomized more limbs correspondingly had the higher feed efficiencies (P < 0.05). Meanwhile, the results also revealed that limb autotomy had no significant effects on the duration of the 2nd molting, the weight growth rate, the specific growth rate as well as the feeding rate in E. sinensis juveniles.Statement of relevanceEriocheir sinensis, as one emerging aquaculture species, has become more popular in Chinese pond culture. However, the high culture density has usually caused a high rate of autotomy among the juveniles and there are still few reports on the effects of autotomy on the survival and growth rate in E. sinensis. The present study was to assess the effect of autotomy on the growth of E. sinensis such as the molting period, weight growth rate, specific growth rate, feeding rate as well as feed efficiency in E. sinensis juveniles, through the individual cultivation method.