Embryonic development of banded gourami, Colisa fasciata in captive condition

Abstract

The experiment was conducted to provide information on the embryonic development of banded gourami, C. fasciata under controlled aquarium condition. The process of embryonic development was divided into seven phases- the zygote, cleavage, morula, blastula, gastrula, segmentation and hatching periods. At fertilization, the eggs were 0.35-0.50 mm in diameter which displayed total length of 0.50-0.70 mm, 22 hours after fertilization. First cleavage was recorded within 35 minutes after fertilization and the embryonic rudiments of developing eggs appeared at 21-22 hours. Cleavage resulted into 64-128 blastomeres and the crown of the blastoderm starts spreading over the yolk in the form of a thin layer in morula stage. In gastrula, blastoderm covered 3/4th of the yolk and embryonic shield was clearly visible. The embryo shows conspicuous muscular contractions and the beating heart at 22 hours after fertilization. This embryonic studies support phylogenetic development by presenting supportive proofs to determine an organism's ancestral forms.