The patterns of limb autotomy in the juvenile swimming crab (Portunus trituberculatus) were investigated in
earth ponds. High incidence of limb autotomy was found in these juvenile crabs accounting for about 28%, and
no significant differences were observed between themales and females (P N 0.05). Both themales and females
with different body sizes performed the autotomy behavior, and the frequency of autotomy remained almost at
the same level. Forelimbs (especially, chelipeds)were lostmore often than posterior limbs (P b 0.05), and the rate
of cheliped loss was the highest. Themajority of crabs (about 87%) were more prone to autotomizing the singleside
limbs than the other crabs (about 13%) that lost both-side limbs equivalently and averagely (P b 0.05). Most
juvenile individuals usually lost one to two chelipeds orwalking legs or swimming legs,while fewer lost three or
more than three limbs, and the fewest lost five limbs.