Observation of embryo and morphological development of larval, juvenile and young speckled snowmark clownfish (Amphiprion sp.)

In order to improve the artificial breeding technology of the speckled snowmark clownfish (Amphiprion sp.), we observed the breeding habits, embryonic development and post-embryonic development under artificial simulated natural conditions. The results show that the fertilized eggs were 1.9−2.1 mm in long diameter and 0.93−0.95 mm in short diameter. The embryonic development mainly went through sperm-egg stage, embryonic disc stage, oogenesis stage, blastocyst stage, protointestinal stage, neuroembryonic stage, organ formation stage and hatching stage. At the water temperature of (27±0.5) ℃, it took approximately 197 h for the fertilized egg to hatch out of the membrane. The newly hatched larvae had a total length of (4.415±0.412) mm, a transparent body, obvious fin membranes, and only a small portion of the yolk sac remained, which had been opened for feeding. Larval stage: At 9 days after hatching DAH, body length of (6.813±0.835) mm), the fin membrane disappeared and the fins formed, and the banding on the head appeared. Juvenile stage: at 21 DAH Body length of (10.581±2.659 mm), accompanied by scale formation on the body, the differentiation of body colour and stripe banding started to appear. Young stage: 35 DAH Body length of (15.512±4.927) mm, four different strains with different body colour patterns were easily identified. In brief, as an artificially selected new variety, the most obvious feature during the post-embryonic development of speckled snowmark clownfish is formation and differentiation of body colour patterns such as stripe banding during juvenile stage.