Abstract:

The spotted scat, Scatophagus argus, is recreational and commercial fish in China and Southeast Asia. In this study, the morphological characteristics of the fertilized eggs of Scatophagus argus on different stages of embryonic development and post-embryonic development were preliminarily observed. The ingestion situation of the larvae and juveniles was also preliminarily observed. The results show the fertilized eggs of Scatophagus argus took 21.5 hours to hatch after the completion of whole embryonic development in sea water with a temperature between 27℃ and 28.5℃, salinity of 26‰ and pH value between 8.10 and 8.25.The total length of the newly hatched larvae was 1.60±0.04 mm, and reached 1.79±0.04 mm over the course of the next four hours with an elliptical yolk sac. In sea water between 28.0℃ and 29.0℃ and salinity of 22- 26‰, the total length of larvae was 2.23±0.05 mm after 24 hours; meanwhile, their yolk sacs were being absorbed visibly. For larvae at five days of age, the total length reached 2.85±0.07 mm and their yolk sacs and oil balls were absorbed completely. The width of their mouth was between 0.17 to 0.18 mm. They were able to ingest larval rotifers, of which the grain size was between 0.10 to 0.12 mm. For larvae at nine days of age, the total length reached 3.25±0.04 mm, Their stomachs and intestines

Key words: morphological characteristics, early development, embryo, larvae, juvenile, young fish