3种不同栖息环境下蟹鳃的超微结构、脂类组成及含量的比较

Ultrastructure and lipid profile of gills in three crabs living in different habitats

为了探讨三疣梭子蟹、无齿相手蟹和中华绒螯蟹的鳃与其所处生境的关系,分别采用电镜和生化手段观察比较了3种蟹鳃丝的超微结构,并分析了其总脂和脂肪酸组成及含量。结果表明,3种蟹鳃丝均具有相似的超微结构,而其鳃中线粒体个数和微绒毛结构差异显著。中华绒螯蟹前鳃的线粒体个数显著高于其他两者(P<0.05),后鳃中三疣梭子蟹的线粒体个数显著低于其它两者(P<0.05);三疣梭子蟹鳃的微绒毛较其余两者稀疏。3种蟹总脂及脂肪酸含量存在一定差异性,其中三疣梭子蟹中甘油三酯(TG)含量最高,前鳃中TG含量高出其余两种蟹3倍以上(P<0.05);无齿相手蟹的胆固醇(Cho)含量显著高于其余两者(P<0.05);磷脂(PL)在3种蟹鳃中的含量均无显著性差异(P>0.05)。花生四烯酸(ARA)和高不饱和脂肪酸(HUFA)在无齿相手蟹鳃中的含量显著高于其他两者(P<0.05)。实验结果表明,3种蟹鳃丝超微结构和脂类含量的差异与其生活的环境密切相关,这更利于其生理功能的正常发挥和对环境的适应。

In order to study the relationship between the ultrastructure,lipid profile of gills and their different habitats,the gills of three typical crabs living in different habitats were chosen as experimental materials.They are Portunus trituberculatus,Sesarma dehaani and Eriocheir sinensis,living in the seawater,estuary（or near freshwater）and freshwater respectively.The ultrastructure and lipid profile were also compared by using electron microscope and biochemistry,aimed to provide the basic data for comparative physiology and biochemistry in crustacean,and promote the understanding of the physiological functions of the ultrastructure and lipid profile in gills.The results indicated that the ultrastructure of gill filaments in the different crabs were similar,with cuticle,epithelial cell and a central haemolymph space,but the amount of mitochondrion and the microvilli in the three kinds of crabs had significant difference：the density of mitochondria in the anterior gills of the Chinese mitten crab was significantly higher than the other two crabs（P0.05）,and in posterior gills of P.trituberculatus was significantly lower（P0.05）.Besides,P.trituberculatus has lower density of microvilli,compared to the other two crabs.The content of triglyceride（TG）in the anterior of P.trituberculatus was higher than that in the others（more than 3 times,P0.05）,also the content of cholesterol（Cho）in the gills of S.dehaani was significantly higher than the other two crabs（P0.05）,while the contents of the phospholipids showed no significant differences between the three kinds of crabs（P0.05）.The gills of S.dehaani have a significantly higher arachidonic acid（ARA）and total highly unsaturated fatty acids（HUFA）content than that of E.sinensis and P.trituberculatus（P0.05）.The result shows that the significant differences in the ultrastructure,contents of total lipids and fatty acids contributed to their normal physiological function and their adaptation to their habitats.