STUDY ON THE MOKPHOGENESIS OF FOETUS AND REPRODUCTIVE REGULARITY OF THE FINLESS POKPOISE, NEOPHOCAENA PHOCAENOIDES

At the early development of the embryo, short bristles were observed on eachside of upper jaw in Neophocaena phocacnoides.The number of the bristles variedfrom 1-3 on the left and 2-3 on the right.Semicircle ear outline was visible. The penis of male foetus was exposed out of body.The swimming organs(flipper,fluke and midway anus to luke notch)developed prominently. As embryo develo-ped,external ear outline of foetus disappeared and the penis of male foetus concea-led in the penial pouch. These morphological changes in the course of the embryo-development indicated that cetacean ancestor might have lived on land and that ce-tacean adapted to water environment whcn coming into water secondly.In addition,statistical analysis on 17 foetuses and juveniles showed that: the growth rate offoetus was 9.08cm/month(0.303cm/day)in Neophocaena phocacnoides, the gesta-tion period may be about 9.4 months in Neophocaena phocaenoides in the YangtzeRiver,and mating may take place from June to August,parturition time fromMarch to Mav each Vear.