School of Aquatic and Fishery Sciences, University of Washington Box 355020, Seattle, WA 98195-5020, USA.
Conserv Biol. 2010 Aug;24(4):1099-110. doi: 10.1111/j.1523-1739.2010.01462.x. Epub 2010 Mar 11.
Crayfishes are both a highly imperiled invertebrate group as well as one that has produced many invasive species, which have negatively affected freshwater ecosystems throughout the world. We performed a trait analysis for 77 crayfishes from the southeastern United States in an attempt to understand which biological and ecological traits make these species prone to imperilment or invasion, and to predict which species may face extinction or become invasive in the future. We evaluated biological and ecological traits with principal coordinate analysis and classification trees. Invasive and imperiled crayfishes occupied different positions in multivariate trait space, although crayfishes invasive at different scales (extraregional vs. extralimital) were also distinct. Extraregional crayfishes (large, high fecundity, habitat generalists) were most distinct from imperiled crayfishes (small, low fecundity, habitat specialists), thus supporting the "two sides of the same coin" hypothesis. Correct classification rates for assignment of crayfishes as invasive or imperiled were high (70-80%), even when excluding the highly predictive but potentially confounding trait of range size (75-90%). We identified a number of species that, although not currently listed as imperiled or found outside their native range, possess many of the life-history and ecological traits characteristic of currently invasive or imperiled taxa. Such species exhibit a high latent risk of extinction or invasion and consequently should be the focus of proactive conservation or management strategies. Our results illustrate the utility of trait-based approaches for taxonomic groups such as invertebrates, for which detailed species-specific data are rare and conservation resources are chronically limited.
螯虾是一种高度濒危的无脊椎动物群体，也是产生许多入侵物种的群体，这些物种已经对世界各地的淡水生态系统造成了负面影响。我们对来自美国东南部的 77 种螯虾进行了特征分析，试图了解哪些生物和生态特征使这些物种容易受到威胁或入侵，并预测哪些物种可能在未来面临灭绝或成为入侵物种。我们使用主坐标分析和分类树评估了生物和生态特征。入侵和濒危螯虾在多维特征空间中占据不同的位置，尽管在不同尺度上入侵的螯虾（区域外 vs. 区域外）也有所不同。区域外的螯虾（体型大、繁殖力高、栖息地广）与濒危的螯虾（体型小、繁殖力低、栖息地专化）区别最大，这支持了“同一枚硬币的两面”假说。即使排除范围大小这一高度预测但可能混淆的特征（75%-90%），螯虾被归类为入侵或濒危的正确分类率也很高（70%-80%）。我们确定了一些物种，尽管它们目前没有被列为濒危物种，也没有在其原生范围之外发现，但它们具有许多与当前入侵或濒危分类群相似的生活史和生态特征。这些物种具有很高的灭绝或入侵的潜在风险，因此应该成为积极保护或管理策略的重点。我们的研究结果表明，基于特征的方法对于无脊椎动物等分类群非常有用，因为这些分类群的详细物种特异性数据很少，而且保护资源长期短缺。
