Optimum dietary protein levels and protein to energy ratios on growth and survival of juveniles spotted Babylon (Babylonia areolata Link) under the recirculating seawater conditions

N. Chaitanawisuti¹*, C. Rodruang² and S. piyatiratitivorakul²

¹Aquatic Resources Research Institute, Chulalongkorn University, Phya Thai Road, Bangkok, Thailand 10330.

²Department of Marine Science, Faculty of Science, Chulalongkorn University, Phya Thai Road, Bangkok, Thailand 10330.

*Corresponding author. E-mail: nilnajc1@hotmail.com.

Accepted 5 January, 2009

   Abstract

A feeding experiment of three dietary protein levels (35, 40 and 45%) and three dietary energy levels (3.8, 4.0 and 4.2 kcal g^-1 diet) factorial design with four replicates  was conducted to determine the proper dietary protein and energy levels for the growth and survival of the juveniles spotted babylon Babylonia areolata under the recirculating seawater conditions. Snails with initial body weight averaging 0.29 ± 0.01 g were fed the experimental diets for 16 weeks. Survival rates (SR) of each group was above 95% and no significant difference among dietary treatments (p > 0.05). Mean weight gain of snails  fed the 35% protein diets with 4.0 kcal/g diet was significantly (P < 0.05) different from that of snails fed the 40 and 45% protein diets at all energy levels. Feed conversion ratio (FCR) was significantly influenced by dietary protein and energy levels (p < 0.05). Diets containing 35% protein level and 4.0 kcal g^-1 energy level appeared to be utilized more efficiently in term of FCR (3.21) than diets containing the other dietary protein and energy levels, ranging 3.62 - 4.54. The results of this study indicate that a diet containing 35% dietary protein and 4.0 kcal g^-1 diets with P/E ratio of 85.99 mg protein/kcal was recommended for juvenile B. areolata growth under our experimental recirculating seawater conditions.

Key words: Babylonia areolata, dietary protein, protein/energy ratio, growth, survival.