Growth and water quality for grow-out of hatchery-reared juvenile spotted babylon (Babylonia areolata) exposed to different water management practices in earthen ponds.

摘要

A 180 day growth trial was conducted to determine growth and water quality for grow-out of hatchery-reared juvenile spotted babylon (Babylonia areolata) in experimental earthen ponds (10.0 10.0 1.2 m) exposed to different water management practices. These practices (T1-T4) consisted of a calcium carbonate addition at 5-day intervals and seawater exchange at 7, 15, and 21 day intervals, respectively. In treatment T4, seawater was exchanged every 7 days without calcium carbonate addition. Results showed that at the end of the experiment, the average body weight gains were 4.41, 3.76, 2.44, and 4.53 g/snail for snails held in the treatments of T1, T2, T3, and T4, respectively, and 0.74, 0.63, 0.41, and 0.76 g mo-1 for those in individual weight gain, respectively. The specific growth rates in body weight were 1.34%, 1.26%, 1.05%, and 1.36% day-1 for snails held in water management treatments of T1, T2, T3, and T4, respectively. Trends similar to those observed in the growth in body weights were observed in those of shell length. No significant difference in final survival was observed among snails held in water management treatments T1, T2, T3, and T4 (range 72.50% to 76.90%). It is recommended to exchange seawater at 7 day intervals either with or without calcium carbonate addition. Both practices provide good results in growth and water quality.