hsan ÇELK
In this study, the morphological development of the larvae of discus fish (Symphysodon spp.) produced under laboratory conditions was observed as of their hatching day until the 32nd day. Larvae were obtained from three pairs of broodstock kept in 60L glass aquaria. All larvae were collected from a single batch and they were kept in the broodstock tank for 32 days. A sample of five individual larva was randomly collected everyday starting at day 1, until 10 DAH and collected every other day 10 DAH between 32 DAH. The larvae were fixed in any solution, were examined under light microscope and photographed using a color video camera. The yolk sac was 1/3 of total length at 1st day that was 1/6 of total length within 4 days. At 3 days, the mouth was open and exclusively rely on exogenous food. Fecal feces was observed from anus at 4 days. There were adhesive glands on the head until 10 days. The body pigmentation was transparent for 7-9 days that increased after 10-15 days. The larvae body shape was disc form like their parents at 30-32 days. The stres bants on the lateral appeared in this period. Larval and prejuvenile period had finished at 30-35 days.
