中华绒螯蟹成蟹养殖池塘常用水草的营养成分比较

The Comparasion of Nutritional Composition of Commonly Used Aquatic Plants in Aquaculture Ponds of Adult Chinese Mitten Crab Eriocheir sinensis

苦草、伊乐藻、金鱼藻和轮叶黑藻是河蟹成蟹池塘养殖过程中的常用水草,本研究通过池塘采样和生化分析方法研究和比较了4种水草的常规营养成分、总类胡萝卜素、脂肪酸组成和氨基酸含量,评价了其营养价值。结果表明:(1)就湿重而言,伊乐藻中水分最低,粗蛋白、粗脂肪、粗纤维和总糖含量均高于其他各水草,苦草中总类胡萝卜素含量最低,而轮叶黑藻中含量最高(P<0.05);就干重而言,轮叶黑藻中的粗蛋白、粗纤维和总类胡萝卜素含量最高,苦草、金鱼藻和伊乐藻中的粗脂肪、灰分和总糖分别含量最高;(2)就脂肪酸组成而言,金鱼藻和轮叶黑藻中的饱和脂肪酸(SFA)含量最高,伊乐藻和苦草中的单不饱和脂肪酸(MUFA)含量较高,伊乐藻中的多不饱和脂肪酸(PUFA)和高不饱和脂肪酸(HUFA)含量最高,四种水草中PUFA均以C18:3n3和C18:2n6为主;(3)就湿重中氨基酸含量而言,伊乐藻中必需氨基酸(EAA)、非必须氨基酸(NEAA)和总氨基酸含量(TAA)均最高,苦草中均最低,金鱼藻和轮叶黑藻居中,TAA含量分别为1.63%和1.30%;就氨基酸干重而言,伊乐藻中的TAA含量最高,金鱼藻中的TAA含量最低,4种水草EAA中均以亮氨酸、赖氨酸、苯丙氨酸、苏氨酸和缬氨酸含量为主,NEAA中则以天冬氨酸、谷氨酸和精氨酸为主,苦草中EAA/TAA比值最高。以上结果表明,成蟹养殖池塘4种常用水草,营养组成具有较强的互补性,根据不同水草的生长规律和营养组成,科学搭配和种植不同水草,可以进一步提高成蟹养殖效果,降低饵料成本。

Vallisneria natans, Elodea nuttallii, Ceratophyllum demersum and Hydrilla verticillata are commonly used aquatic plants in the aquaculture ponds of adult Eriocheir sinensis, and this study was conducted to determine and evaluate the nutritional value of the four type of aquatic plants, including proximate composition, total carotenoids, fatty acid composition and amino acid contents by the pond-sampling and biochemical analysis. The results indicated that：（1） Based on the percentage of wet weight, the moisture content of E. nuttallii was the lowest among the four aquatic plants, while the contents of crude protein, crude fat, crude fiber,and total carbohydrate were higher than the other aquatic plants. The lowest total carotenoid content was observed in V. natans, while H. verticillata had the highest total carotenoid content among of them（P0.05）; in terms of dry weight, H. verticillata has the highest content of crude protein, crude fiber and total carotenoid while V. natans, C. demersum l. and E. nuttallii have the highest content of total lipid, crude ash and total carbohydrate respectively.（2） As for the fatty acid profile, C.demersum l. and H. verticillata had the highest content of saturated fatty acid（SFA） while the highest content of mono-unsaturated fatty acids（MUFA） was observed in E. nuttallii and V. natans, E. nuttallii has the highest content for polyunsaturated fatty acid（PUFA）and highly unsaturated fatty acid（HUFA）. For the PUFA composition of four types of aquatic plants, particularly, the major constituent of C18：3n3 and C18：2n6.（3） In terms of amino acid content based on the wet weight,E. nuttallii. had the highest the essential amino acid（EAA）, non-essential amino acid（NEAA） and total amino acid content（TAA） among of four types aquatic plants, and the lowest of these amino acids were found in V.natans. C. demersum l. and H. verticillata are located in the middle position, with TAA content of 1.63% and 1.30%, respectively; As for the amino acid content of the dry weight, the highest content of TAA was also found in E. nuttallii, however, the lowest content of TAA was observed in C. demersum l. The contents of leucine, lysine, phenylalanine, threonine and valine were dominated EAAs among all amino acids while the major NEAAs were aspartic acid, glutamic acid and arginine, and V. natans had the highest ratio of EAA/TAA.These results suggested that four types of commonly used aquatic plants are highly complementary in term of nutritional composition for E. sinensis, which could be used in the aquaculture ponds of adult E. sinensis to improve culture performance as well as to reduce the costs of feeds by appropriate planting and matching.