The ingestion, growth and ecological conversion efficiency of Hippocampus kuda under the intensive rearing conditions

Hippocampus kuda Bleeker is an official oceanic fish in Chinese traditional medicine. Because of the great contradiction between supply and need , the nature resources of Hippocampus kuda Bleeker have declined sharply. The food consumption , growth and ecological conversion efficiency of H. kuda were studied in the Commercial Rearing Base Guangdong Richvast , the South China Sea , Guangdong Province. The Elliott2Persson model and Eggers model were used to determine its feeding periodicity , to quantify its food consumption quantity , consumption rate ,evacuation rate and food as well as energy conversion efficiency. The results indicated that seahorse (the range of body length 88. 5 -141. 3mm , body weight 5. 75 -13. 27g wet) fed in daytime with two peaks in 12 :00 and 18 :00 and were not fed in nighttime (the density is 200 ind·m 3 , DO is beyond 5. 5mg ·L -1 , BOD is below 3mg·L-1,pHis 7.5-8.2,transparencyis 50-85cm,salinityis 15.2-26.5). The mean daily food consumption of H. Kuda was 16. 634 2 ±0. 782 0g·(100g) 1 per day. The food consumption rate was 1 177. 25 cal ·ind -1 per day and evacuation rate was 0. 144 4g·(100g) -1 ·h -1. Its food and energy conversion efficiency was 20. 04 % and 31. 42 % respectively. The mean growth speed of its body length and daily growth rate was 1. 176 6mm per day and 1. 27 % respectively . The mean body weight growth speed of H. kuda and daily body weight growth rate were 0. 182 0g per day and 2. 27 % respectively. The food consumption of seahorse correlated with enviromental water temperature significantly ( P < 0. 01) . It can be expressed by the formula : FC =0.458 4+0.626 8 T ( P < 0. 01) . The relationship between the food consumption rate and its body weight as well as water temperatuer can be experssed better by the formula C =6.754 4 0.3014 T 0. 219 0 W ( F = 83. 596 3 F0.01 =18.00 F > F0.01)) .