Morphological Embryonic Development Stages of Barbonymus gonionotus (Bleeker, 1850)

Abstract

Morphological study on embryonic development of Barbonymus gonionotus (Bleeker, 1850) was described under laboratory condition. Fertilization occurred at 16 hours after injection. Ten minutes after fertilization, the one cell stage of embryos and unfertilized eggs were observed. The developmental stages were observed and divided into early cleavage stage, morula stage, blastula stage, gastrula stage, somite formation stage, hatching stage and larval stage. The one-cell embryo of fertilized egg develops subsequently through the first, second, third, fourth and fifth cleavage. After thirty- two cell stage, morula stage was observed after 25 minutes postfertilization followed by blastula stage. Gastrula stage appeared at 2 hours 50 minute after fertilization. After gastrula stage, the embryo transformed into bud stage at 5 hours. Further development of a pair of mesodermal somite formation, appearance of notochord and heart, were observed after 9 hours after fertilization. Thirty-three somite formation stage was observed at about 12 hours and 39 minutes. Anal structure was observed and located between 22 and 23 myomeres. After 15 hours, the development of all cells was completed. Hatching occurred about 16 hours after fertilization, the membrane