Breeding and embryonic development of angelfish (Pterophyllum scalare)

Abstract

This study investigated the breeding behavior, embryonic development, and physicochemical parameters of Pterophyllum scalare, commonly known as the angelfish. Breeding trials were conducted over a six-month period at the Meghalaya State Fisheries Research and Training Institute, Mawpun from July to December 2023. Physicochemical analyses of the breeding and broodstock tanks showed variations in temperature (26-28°C), pH (6.2-7.2), dissolved oxygen (4-5 ppm), hardness (120-146 ppm), and alkalinity (126-154 ppm). Morphometric analysis revealed male angelfish measuring 15 cm in length and 18 g in weight, while females measured 13 cm and 15 g, respectively. The fertilization rate was 85%, with a hatching rate of 60% and a survival rate of 35%. Embryonic development stages were meticulously observed, documenting key milestones such as the first cleavage completed within 35 minutes, progressing through stages including 2-cell, 4-cell, 8-cell, 16-cell, blastula, dome, gastrula, segmentation, and hatchling emergence at 72 hours post-fertilization. This comprehensive study provides valuable insights into the reproductive biology and early life stages of Pterophyllum scalare, essential for its aquaculture and conservation management.