英文摘要 |
This study investigated the effects of three different stocking densities (designed as high, 60 sea urchin/m2, mdeiun, 40 sea urchin/m2, and low, 20 sea urchin/m2) and two differerent diets, artificial diet and Gracilaria on the growth, survival and gonad-somatic index of two kinds of sea urchin, Anthocidaris crassispina and Tripneustes gratilla in the plane and tier cultivated systems. In the plane cultivated system, 70 g Anthocidaris fed with artificial diet with mdeium density had the highest weight gain and gonad-somatic index. However, the weight gain of Anthocidaris fed with artificial diet with mediun density had no significant difference with the Anthocidaris fed with artificial diet with low density and the Anthocidaris fed with Gracilaria with medium density. The gonad-somatic index of Anthocidaris fed treatment diets excluded Anthocidaris fed artificial diet with high density had no significant difference. Regardless of the different densities, 140 g Tripneustes fed artificial diet had significant higher weight gain and gonad-somatic index than those fed Gracilaria in the plane cultivated system. In the tier cultivated system, the weight gain of 34 g Anthocidaris fed artificial deit or Gracilaria under different densities had no significant difference. However, the gonad-somatic index of 34 g Anthocidaris fed with artificial diet had higher significant difference than those fed with Gracilaria, 155 g Tripneustes under different densities fed with artificial diet had significantly different higher gonad-somatic index and weight gain than those fed with Gracilaria. Anthocidaris cultured in outdoor plane experiment system, fed either artificial diet or Gracilaria had high survival (79%). However, they were cultured in outdoor tier experiment system fed either artificial diet or Gracilaria had low survival (20-30%). |