Larval Development of Siamese Fighting Fish (Betta splendens Regan, 1910)

Abstract

In this study, the larval development stages of one of the most important ornamental fish Siamese fighting fish betta (Betta splendens Regan, 1910) were examined. The larval development stage was documented from hatching until the beginning of the juvenile period. The fertilized eggs were incubated at a water temperature of 28±0.5°C. The embryonic developmental stage was completed and hatching was observed at 28-32 hours post fertilization (hpf). The mouth and anus were closed 1 day after hatching (DAH). The mouth and anus were opened at 2 DAH. Exogenous feeding started on 3 DAH. The swim bladder was inflated at 2–3 DAH. The yolk sac was completely consumed at 4 DAH and the larvae began to swim freely. The larval development of Betta splendens was divided into four different periods: Yolk-sac larva (1–4 DAH), preflexion larva (4–8 DAH), flexion larva (11-12 DAH) and post-flexion larva (13–30 DAH). The larval metamorphosis was completed, and the larvae transformed into juveniles at 30 DAH.