Embryonic development of cobia, Rachycentron canadum (Linnaeus,1766) in controlled conditions

Abstract

Cobia, Rachycentron canadum has emerged as a global species for aquaculture in the recent past. Eventhough seed production of cobia is being practiced at many tropical countries, there is very little information on the embryonic development of the species. The details of fertilized eggs, cleavage, embryonic phases and newly hatched larva are documented with photographs. The experiments were carried out at a temperature range of 28.5-30°C. The average diameter of the freshly spawned eggs ranged from 1.1 to 1.2 mm. The time of different stages of development after fertilization is provided. The larva hatched out after 22 hours of fertilization. The total length of the larvae ranged from 2.2 to 2.7 mm. The newly hatched larva was without mouth opening and with a prominent oil globule. The description given in the paper can be made use of in the larval production of cobia in hatcheries.