White Shrimp Litopenaeus vannamei that Fed Diets Containing Gracilaria tenuistipitata Extract and Carrageenan Showed Protective Immunity after Salinity Stress

Abstract

A control diet, a diet containing 1.0 g/kg Gracilaria tenuistipitata extract (GTE), and a diet containing 1.0 g/kg carrageenan were prepared. Body weight and length of white shrimp Litopenaeus vannameithat fed three diets in 35 per mille salinity after 0, 3, 6, and 12 weeks were examined. No significant differences in weight and length of shrimp were observed among three diets. Hyaline cells (HCs), granular cells (including semi-granular cell, GCs), total hemocyte count (THC), phenoloxidase (PO) activity, respiratory burst (RB), and lysozyme activity were examined 12 weeks after shrimp fed three diets, and at 12 h post salinity stress (salinity change from 35 per mille to 25 per mille). No significant differences in immune parameters were observed among shrimp that fed three diets after 12 weeks. HCs, GCs, THC, PO activity, RB, and lysozyme activity of shrimp that fed GTE diet or carrageenan diet after 12 weeks were significantly higher than those of shrimp that fed the control diet at 12 h post salinity stress. In conclusion, shrimp that fed diets containing 1.0 g/kg GTE or 1.0 g/kg carrageenan all showed protective capability in immunity at 12 h post salinity stress as an evidence of higher immune parameters, despite of no significant differences in immune parameters of shrimp among three diets after 12 weeks.配製一組對照組飼料，一組含1.0 g/kg龍鬚菜萃取物，以及一組含1.0 g/kg鹿角菜膠，共3個處理組。白蝦分別以此3種飼料餵食，經0、3、6、12週後，檢測白蝦的體重、體長，3組的體長與體重無顯著差異。白蝦經分別餵食3種飼料，12週後以及餵食12週再經鹽度緊迫(鹽度千分之35移至鹽度千分之25) 12小時後，分析透明球、顆粒球(包含半顆粒球)、總血球、原酚氧化酵素活性、呼吸爆以及溶菌酶活性，發現12週後，免疫因子無顯著差異。但是經鹽度緊迫12小時後，餵食含1.0 g/kg龍鬚菜萃取物以及餵食含1.0 g/kg鹿角菜膠飼料的白蝦，其透明球、顆粒球、總血球、原酚氧化酵素活性、呼吸爆以及溶菌酶活性均顯著地高於對照組。因此，即使白蝦經餵食12週後，各組間免疫因子無顯著的差異，但經鹽度緊迫12小時後，仍具較高的免疫因子，證實餵食含1.0 g/kg龍鬚菜萃取物或1.0 g/kg鹿角菜膠飼料的白蝦，具有免疫保護的能力。