Food sources and trophic relationships of three decapod crustaceans: insights from gut contents and stable isotope analyses
Food sources and trophic relationships of three decapod crustaceans: insights from gut contents and stable isotope analyses
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DOI：
10.1111/are.12739
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发表时间：
2016-09
影响因子：
2
通讯作者：
Zhigang Mao;X. Gu;Qingfei Zeng
中科院分区：
文献类型：
--
作者：
Zhigang Mao;X. Gu;Qingfei Zeng
中华绒螯蟹（Eriocheir sinensis）、日本沼虾（Macrobrachium nipponensis）和克氏原螯虾（Procambarus clarkii）是我国重要的养殖品种，也是世界性的引种品种。这三种十足类的营养作用还没有在一个系统内进行比较，虽然它们消耗植物，动物和碎屑，并经常共同出现在淡水池塘。采用稳定同位素测量和肠道内容物分析相结合的方法，确定了固城湖商业蟹池中3种底栖十足类的主要食物来源和营养生态位。观察肠道内容物反映了各种猎物的项目摄入的三十足类。水生植物对肠道内容物体积的贡献最大，其次是饲料鱼、玉米和软体动物。稳定同位素分析支持小龙虾与植物物质之间的关系比与动物物质之间的关系更强，而螃蟹和虾则相反。同位素混合模型表明，大约60%的螃蟹和虾的生产来自动物物质，而只有40%的小龙虾生产归因于动物物质的消费。虽然混合模型的结果证实了在大多数情况下的肠道内容物的结果，稳定同位素的结果表明，三十足类动物获得更多的能量从动物物质的增长比将估计，如果肠道分析单独使用。生态位重叠指数的估计表明，高度的饮食重叠之间的三个十足类检查，这表明，虾和小龙虾的密度应加以控制，如果考虑池塘养殖的经济效益。
Chinese mitten crab (Eriocheir sinensis), freshwater shrimp (Macrobrachium nipponensis) and red swamp crayfish (Procambarus clarkii) are important culture species in China and have world-wide introduced distributions. The trophic role of these three decapods has not been compared within a system although they consume plants, animals, and detritus and often co-occur in freshwater ponds. A combination of stable isotope measurements and gut content analysis was used to determine the main food sources and trophic niche of three benthic decapods, in commercial crab ponds around Lake Gucheng, China. Observation of the gut contents reflected a variety of prey items ingested by three decapods. Macrophytes made up the highest contribution to the volume of their gut contents, followed by forage fish, corn and mollusks. Stable isotope analysis supported a stronger relationship between crayfish and vegetable matter than with animal matter, while both crab and shrimp were the opposite. An isotopic mixing model indicated that about 60% of crab and shrimp production originated from animal matter, while only 40% of crayfish production was ascribed to consumption of animal matter. Although results from the mixing model corroborate the gut content findings in most cases, stable isotope results showed that three decapods obtained more energy for growth from animal matter than what would be estimated if gut analysis was used alone. Estimates of niche overlap indices indicated a high degree of dietary overlap among the three decapods examined, suggesting that shrimp and crayfish density should be controlled if considering economic benefits of pond aquaculture.