Effects of intrinsic factors and different salinity levels on the hemolymph osmolality and Ion regulation of Macrobrachium rosenbergii

• Main Authors: Chin-Hsin Chen, 鄭熾信
• Other Authors: Jiann-Chu Chen
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/60895049027622401176

碩士 === 國立海洋大學 === 水產養殖學系 === 88 === The giant freshwater prawn Macrobrachium rosenbergii (De Man) was examined for hemolymph oxyhemocyanin, protein, osmolality and ion concentractions in relation to size and the molt cycle. No significant difference in hemolymph protein levels was observed between male and female prawns. The hemolymph oxyhemocyanin and ratio of oxyhemocyanin to protein in large male prawns (52.7-113.38g) was significant lower than female and small male prawns (10.89-48.14g). The decreases in hemolymph protein, oxyhemocyanin, osmolality, Na+, Cl-, K+, Mg2+, and Ca2+ levels can be corrlated with the faster somatic growth and sexually behavior character. With regard to the molt cycle, hemolymph protein (170.24 ± 7.63 mg/ml) and oxyhemocyanin (2.01 ± 0.05 mmol/l) was the highest at stage D0/D1. The lowest protein (110.18 ± 1.48 mg/ml) and oxyhemocyanin (1.39 ± 0.01 mmol/l) were measured at stage A. The fact that the hemolymph protein, osmolality, Na+, Cl-, K+ and Ca2+ levels were lower during the postmolt period, and higher during intermolt and early premolt that were considered to be associated with water uptake at molt. Macrobrachium rosenbergii which were reared in different salinity levels at 0, 7, 14 and 21 ppt after 14 days survived at 95.7 %, 90.0 %, 79.5 %, 52.9 % and 96.3 %, 91.3 %, 72.2 %, 43.1 % for male and female, respectively. The prawns which had been acclimated to freshwater survived 91 %, 85 % 83 % and 64 % after 15 days when transferred suddenly to 0, 7, 14 and 21 ppt, respectively. The prawns which had been acclimated to 7, 14 ppt survived more than 80 % when transferred suddenly to 0, 7, 14 and 21 ppt. However, the prawns which had been acclimated to 21 ppr survived 56 %, 77 %, 84 % and 61% when transferred suddenly to 0, 7, 14, and 21 ppt, respectively. The prawns are strong hyperosmotic regulation in water over the range of 0 to14 ppt, with hemolymph mean osmolality of 430 mOsm/kg for male and female, respectively.