Abstract: Giant salamanders(Andrias davidianus) belongs to Chordate, Amphibia, Caudata, salamander Cryptobranchus branch, is an unique amphibian species in China. The morphological characteristics of aquatic organism have influences on its fecundity, but such influences have not been reported in A. davidianus. In order to support the artificial breeding of A. davidianus, the GAM model was applied to evaluate the effects of body weight, body length, relative fatness and bust girth on the fecundity of F2 sexual mature giant salamanders. The results suggested that all 4 growth factors of F2 broodstock had significant influences on the fecundity. The influences of body length and relative fatness were nonlinear increasing. The body weight had a clear monotonic negative effect on the fecundity. The influence on the fecundity was fluctuant when the bust girth was below 380 mm, and above that the fecundity decreased rapidly with the increasing of bust girth. The range of body length, body weight, bust girth and relative fatness that had great influences on the fecundity of F2 A. davidianus broodstock were 800-1000 mm, 4000-7000 g, 350-400 mm and 0.6-1.0, respectively.

Key words: Andrias davidianus, F2 broodstock, fecundity, GAM