عنوان مقاله [English]
Significant morphological and physiological changes occur in the early development of fishes. This study was conducted to investigate the embryonic and pre-larval development of fighting fish (Betta splendens) in different temperature (24, 27 and 30°C) from oocyte activation to time of free swimming. Spawning occurred in tanks at 28 °C. Fertilized eggs were removed rapidly from the breeding tanks and put in the rearing tanks with different temperature (24, 27 and 30 °C). Diameter of fertilized eggs was determined around 0.8 mm. They were white, typically when deposited, very large vitellogenin and small privitelin space. Eggs and larva in different development stages and temperatures were sampled and taken pictures. The minimum time for arrival to specific developmental stages including: first cleavage, 32 and 64 cells stage, mid blastula stage, 50% epiboly, tail bud formation, heartbeat begins, hatching, opening the mouth and finally free swimming) at 24, 27 and 30 °C was recorded. Higher hatching rate and larva faster growth occurred at 30°C show that this temperature is most suitable for egg incubation of Siamese fighting fish.