小龙虾，通常称为鳌虾，它主要栖息于臭水沟中，引种的最初目的是为了疏通下水道，在我国许多地区也有引种，可是最后它成了我们餐桌上的一道美食，在很多城市的街道上随处可见供应小龙虾这道美食的餐管，尤其是在武汉，还有专门吃小龙虾的季节，那时，整个城市都迷散着小龙虾的香味。
此外，小龙虾还是研究白斑综合症病毒（WSSV）的理想模型动物，尤其是在前几年WSSV肆掠时，它是众多WSSV研究者首选的模型动物，就象我们其他研究用到的小鼠一样，利用这种动物，对WSSV的形态结构、流行病学、基因组学、组织病理学及防治进行了大量研究，并取得了可喜进展。
作为引入物种，它引起了引种地区的生态系统问题，迅速成为当地的优势物种并蔓延至更广范围，这跟英国出现的问题相类似。另外，因为其生存环境，小龙虾带有大量病毒与寄生虫，而且体内累积大量重金属，因而通过引种，这些病毒与寄生虫得以更广地传播，给引种地本地生物带来新的威胁。在品尝小龙虾时，是不是想到它的生存环境而味口尽失？
小龙虾之所以会成为引种地的优势物种，原因不单是它们的数量，更重要的是它们的生活习性，即食量大、不挑食、适应性强。尽管目前没有发现什么大型疾病流行，到底有没有潜在风险谁也不能肯定，可以肯定的是这对整个生态系统有巨大影响。
这就是提醒我们，在从一个产地到另一个产地引种动物和植物时，必需要考虑引种物的寄生虫作用与引种物如何传播及其管理策略。（生物谷bioon.com）
doi:10.1371/journal.pone.0032229
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Predatory Functional Response and Prey Choice Identify Predation Differences between Native/Invasive and Parasitised/Unparasitised Crayfish
Neal R. Haddaway, Ruth H. Wilcox, Rachael E. A. Heptonstall, Hannah M. Griffiths, Robert J. G. Mortimer，Martin Christmas, Alison M. Dunn
Background：Invasive predators may change the structure of invaded communities through predation and competition with native species. In Europe, the invasive signal crayfish Pacifastacus leniusculus is excluding the native white clawed crayfishAustropotamobius pallipes. Methodology and Principal Findings：This study compared the predatory functional responses and prey choice of native and invasive crayfish and measured impacts of parasitism on the predatory strength of the native species. Invasive crayfish showed a higher (>10%) prey (Gammarus pulex) intake rate than (size matched) natives, reflecting a shorter (16%) prey handling time. The native crayfish also showed greater selection for crustacean prey over molluscs and bloodworm, whereas the invasive species was a more generalist predator. A. pallipes parasitised by the microsporidian parasite Thelohania contejeani showed a 30% reduction in prey intake. We suggest that this results from parasite-induced muscle damage, and this is supported by a reduced (38%) attack rate and increased (30%) prey handling time.Conclusions and Significance：Our results indicate that the per capita (i.e., functional response) difference between the species may contribute to success of the invader and extinction of the native species, as well as decreased biodiversity and biomass in invaded rivers. In addition, the reduced predatory strength of parasitized natives may impair their competitive abilities, facilitating exclusion by the invader.
