Embryonic and Pre-Larval Development of Shabbout (Barbus grypus H.)

Abstract

As a preliminary step towards assessing its aquaculture potential, egg development and artificial breeding in shabbout (Barbus grypus Heckel 1843) was studied. Artificial insemination was achieved by mixing eggs and a sperm-testes extract. The fertilization rate was 60%. Diameters of fertilized eggs ranged 2.58-2.70 mm. The perivitelline space formed 20 min after insemination and contained no oil droplets. A blastodisc split two blastomeres of nearly equal size 80 min after insemination and first cleavage occurred 4-4.5 h after insemination. The gastrula stage was completed after 12.5 h and the embryonic body formed after 14 h. The first somites were observed at 28 h and the first heartbeat at 72 h. The first hatched larva appeared at 84 h and all eggs hatched within 92 h. The mouth opening occurred after 188 h. Head pigmentation was nearly complete together with the formation of the tail fin by 480 h, after which the tail fin gained its homocercal formation and the pigmentation spread throughout the body.