Evaluation of nursery rearing of pearl spot (Etroplus suratensis) in freshwater

Abstract

Pearl Spot (Etroplus suratensis), a euryhaline cichlid of high commercial value, has traditionally been cultured in brackish water systems. This study evaluates its nursery rearing performance in freshwater conditions, focusing on the critical developmental phases from spawn to fry and fry to fingerling. Experimental trials were conducted using tank nursery setups, with systematic monitoring of water quality parameters including temperature, dissolved oxygen, pH, ammonia, nitrite, and alkalinity. The results indicate that stable water quality particularly dissolved oxygen above threshold levels and pH within optimal range was essential for larval survival and growth. Natural plankton communities, dominated by Chlorophyceae and Rotifera, contributed significantly to early nutrition and gut development. The species exhibited steady increases in length and weight across both phases, with survival rates conducive to scalable seed production. The findings affirm the adaptability of Pearl Spot to freshwater nursery systems and underscore the importance of water quality management in optimizing hatchery outcomes.