Morphological identification of wild,pond-farm and mangrove eco-farm adult Bostrychus sinensis

ObjectiveMorphological difference among three Bostrychus sinensis populations with different sources was compared to find out a quick morphological identification method for the source of B. sinensis and provide some sci-entific basis for establishing mangrove eco-farm B. sinensis brand.MethodSix measurable morphological characters and twenty truss network data of wild B. sinensis,B. sinensis cultured in mangrove underground tube system and B. sinensis raised in pond were measured and then analyzed with multivariate analysis methods,including variance analysis,cluster analysis,discriminant analysis,and principal component analysis.ResultDifference in ratios of the measurable charac-ters among the three populations were obvious except for the ratio of head length/body length. The results of principal component analysis showed that the first principal component was greatly influenced by the eigenvalues of tail end like L9 (distance between origin of the second dorsal fin and posterior of the second dorsal fin),L13(distance between posterior of the second dorsal fin and origin of anal fin),L14(distance between posterior of the second dorsal fin and dorsal origin of caudal fin),L17(distance between posterior of the second dorsal fin and ventral origin of caudal fin),length of tail/length of body,and height of tail/length of tail. The second principal component was greatly influenced by the eigenvalues of body like height of body/length of body,L2(distance between origin of the first dorsal fin and insertion of pelvic fin), L5(distance between origin of the second dorsal fin and origin of anal fin),L6(distance between insertion of pelvic fin and origin of anal fin),L7(distance between origin of the first dorsal fin and origin of anal fin),and L8(distance be-tween origin of the second dorsal fin and Insertion of pelvic fin). The third principal component was greatly influenced by the eigenvalues of rear end like L11(distance between origin of anal fin and posterior end of anal fin),L12(distance be-tween origin of the second dorsal fin and posterior end of anal fin),L16(distance between posterior end of anal fin and ventral origin of caudal fin),L18(distance between posterior end of anal fin and dorsal origin of caudal fin). Morphologi-cal difference among wild,pond-farm and eco-farm B. sinensis was obvious and therefore they could be identified by using discriminant function. The comprehensive correction rate was 93.1%. The result of cluster analysis showed that wild B. sinensis constituted a cluster with eco-farm B. sinensis first and then clustered with pond-farm B. sinensis,imply-ing that wild B. sinensis was morphologically similar to eco-farm B. sinensis.ConclusionThere are obvious differences in morphological characters of wild B. sinensis,B. sinensis cultured in mangrove underground tube system and B. sinensis raised in pond,and they can be identified by morphological multivariate analysis. B. sinensis cultured in mangrove under-ground tube system is more morphologically similar to wild B. sinensis. Food supply,food composition,physical and chemical condition of environment may be main reasons for morphological difference of different populations of B. sinensis.