Study On Nutrition Physiology Of Carbohydrate And Manganese In Abalone (Haliotis Discus Hannai Ino)

Feeding experiments were conducted to determine the optimum dietary requirement of carbohydrate and manganese for juvenile abalone(Haliotis discus hannai Ino) with dextin as carbohydrate sources, manganese sulfate (MgSO4?H2O) as manganes sources, Results of the present study are presented as follows:1. A 112-day growth experiment was conducted in a recircle water system to investigate growth responses of abalone (H. discus hannai Ino) to dietary carbohydrate. Triplicate groups of juvenile abalone (initial weight: 3.46±0.02 g; initial shell length: 29.52±0.10mm) were fed to satiation one of 6 semi-purified diets supplemented 0, 10, 20, 30 and 40% carbohydrate. Contents of total carbohydrate in these diets were analyzed as 5.00%, 11.88%, 20.03%, 31.05% and 39.14% respectively. Results showed that there were no significant differences in the daily increment in shell length (DISL) and the survival of abalone (P>0.05). However, weight gain rates (WGR) were significantly affected by dietary carbohydrate (P<0.05). The highest WGR was found in the treatment with 31.05% dietary carbohydrate. Contents of lipid, ash and moisture in the soft body were not significantly influenced by dietary carbohydrate (P>0.05). Contents of protein in the soft body were significantly decrease with the raise of the dietary carbohydrate. these results suggested the optimal dietary carbohydrate level for growth in abalone was 24.34%.2. A 168-day growth experiment was conducted in a flow-through water system to investigate growth responses of abalone H. discus hannai Ino to dietary manganese. Triplicate groups of juvenile abalone (initial weight: 0.70±0.03 g; initial shell length: 17.72±0.03 mm) were fed to satiation one of 6 semi-purified diets supplemented 0, 10, 20, 40, 80 and 320 mg/kg manganese. Contents of manganese in these diets were analyzed as 6.0, 16.9, 28.9, 46.5, 89.7 and 361.7 mg/kg, respectively. Results showed that there were no significant differences in the daily increment in shell length (DISL) and the survival of abalone (P>0.05). However, weight gain rates (WGR) were significantly affected by dietary manganese (P<0.05). The highest WGR was found in the treatment with 28.9 mg/kg dietary manganese. Contents of protein, lipid, ash and moisture in the soft body were not significantly influenced by dietary manganese (P>0.05). The muscle Mn concentration in the group with 28.9 mg/kg dietary manganese was significantly higher than those in other groups (P<0.05). Based on these results, the adequate dietary manganese concentration for growing H. discus hannai estimated by growth data and Mn deposition is about 28.9 mg/kg by growth data and Mn deposition.