Long Xiaowen, Wu Xugan, Zhao Lei, Ye Haihui, Cheng Yongxu, Zeng Chaoshu
College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.
Centre for Research on Environmental Ecology and Fish Nutrition of Ministry of Agriculture, Shanghai Ocean University, Shanghai, China.
PLoS One. 2017 Jun 19;12(6):e0179036. doi: 10.1371/journal.pone.0179036. eCollection 2017.
As a catadromous species, salinity is a key parameter that affects gonadal development of Chinese mitten crab Eriocheir sinensis during reproductive migration. It is however unclear the effects of salinity on the gonadal development of male E. sinensis as well as their physiological responses to salinity during reproductive migration. This study investigated the effects of four salinities (0 ‰, 6 ‰, 12 ‰ and 18 ‰) on gonadal development, osmoregulation and metabolism of adult male E. sinensis over a 40-day period. The results showed that elevating salinity promote gonadal development, increase hemolymph osmolality and K+ and Mg2+ concentrations (P < 0.05). The 12 ‰ salinity resulted in the highest contents of taurine and arginine in the hemolymph while the highest contents of threonine, phenylalanine, lysine, ß-alanine, tryptophan, ornithine and total free amino acids were found for 0 ‰ treatment (P < 0.05). A decreasing trend was detected for the Na+/K+-ATPase activity and its mRNA expression level in the posterior gills with salinity (P < 0.05). Total saturated fatty acids in the anterior gills decreased with increasing salinity (P < 0.05); the 0 ‰ treatment had the highest total polyunsaturated fatty acids in the posterior gills while total n-6 polyunsaturated fatty acids increased with salinity (P < 0.05). The hemolymph glucose and uric acid showed a decreasing trend as salinity while an increasing trend was found for the hemolymph triglyceride and high-density lipoprotein cholesterol (P < 0.05). The 12 ‰ treatment had the highest levels of hemolymph malonaldehyde and hepatopancreatic γ-glutamyltranspeptidase (P < 0.05). In conclusion, these results suggested that the brackish water promote gonadal development of male E. sinensis, and increase osmolality and ionic concentrations in hemolymph while reduced the activity of Na+ /K+- ATPase and its mRNA expression in the posterior gills as well as metabolism.
作为一种降海洄游性物种，盐度是影响中华绒螯蟹生殖洄游期间性腺发育的关键参数。然而，盐度对雄性中华绒螯蟹性腺发育的影响以及它们在生殖洄游期间对盐度的生理反应尚不清楚。本研究调查了4种盐度（0‰、6‰、12‰和18‰）在40天时间内对成年雄性中华绒螯蟹性腺发育、渗透压调节和代谢的影响。结果表明，提高盐度可促进性腺发育，增加血淋巴渗透压以及钾离子和镁离子浓度（P<0.05）。12‰盐度处理使血淋巴中牛磺酸和精氨酸含量最高，而0‰处理组苏氨酸、苯丙氨酸、赖氨酸、β-丙氨酸、色氨酸、鸟氨酸和总游离氨基酸含量最高（P<0.05）。随着盐度升高，后鳃中钠钾ATP酶活性及其mRNA表达水平呈下降趋势（P<0.05）。前鳃中总饱和脂肪酸含量随盐度升高而降低（P<0.05）；0‰处理组后鳃中总多不饱和脂肪酸含量最高，而总n-6多不饱和脂肪酸含量随盐度升高而增加（P<0.05）。血淋巴葡萄糖和尿酸含量随盐度升高呈下降趋势，而血淋巴甘油三酯和高密度脂蛋白胆固醇含量呈上升趋势（P<0.05）。12‰处理组血淋巴丙二醛和肝胰腺γ-谷氨酰转肽酶水平最高（P<0.05）。总之，这些结果表明，半咸水促进雄性中华绒螯蟹性腺发育，增加血淋巴渗透压和离子浓度，同时降低后鳃中钠钾ATP酶活性及其mRNA表达以及代谢水平。
