Abstract

Onyia, L.U. Ladu, B.M.B. and Olufeagba, S.O

The need to carry out a thorough study on the embryogenesis of intra-specific Clarias anguillaris to determine the best time and the implication in chromosome engineering research cannot be overemphasized. In this study, it was observed that the first cleavage into 2-cell stage was 34minutes after fertilization, which gave the right timing for the production of tetraploids. The 4-cell, 8-cell and 16-cell stages occurred at 47 minutes, 52 minutes and 53 minutes respectively. Fifty-four percent (54%) of the embryo attained morula stage at 94 minutes. Other embryonic stages observed include blastula, gastrulation, somite formation and hatching. Hatching started at 18hours after fertilization and lasted for a period of about 6hours. The hatchlings increased in length at 0.2mm/day in the first 5 days after hatching