Size and shape variation of two freshwater crabs in Argentinean Patagonia: The influence of sexual dimorphism, habitat, and species interactions
Size and shape variation of two freshwater crabs in Argentinean Patagonia: The influence of sexual dimorphism, habitat, and species interactions
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DOI：
10.1651/07-2824r.1
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发表时间：
2008-02-01
影响因子：
1.1
通讯作者：
Loy, Anna
中科院分区：
文献类型：
--
作者：
Giri, Federico;Loy, Anna
采用几何形态计量学研究了neuquensis和a . riolimayana的形态差异。标本包括来自阿根廷巴塔哥尼亚河流和湖泊的异域和同域种群。对对称处理后的16个标志进行头胸形状分析，这些标志代表所有标本的一半构型。权重矩阵的排序分析揭示了两个物种之间的明显区别。对neuquensis和a.i. riolimayana的权重矩阵进行多变量检验，P < 0.0001。两种雌、雄差异显著（P < 0.0001）。neuquensis和a.i. riolimayana的雌性呈现出更宽的后部区域，可能是为了携带卵和幼崽。第一个相对扭曲清楚地表明，生活在河流中的螃蟹与生活在湖泊中的螃蟹在形状上存在差异（P < 0.0001）。湖泊标本的喙部比河流个体的喙部更紧凑。这可能与两种系统的动力学差异有关。异域居群中的neuquensis外形与riolimayana相似，而同域居群中的neuquensis外形更接近于“典型”的neuquensis外形。因此，异域居群以某种方式出现，以扩大他们的形状向紫叶孤树。
The morphological variation of Aegla neuquensis and A. riolimayana was studied using a geometric morphometric. Specimens included both allopatric and sympatric populations from rivers and lakes of the Argentinean Patagonia. Cephalothorax shape was analyzed throughout 16 landmarks representing the half configurations of all specimens after symmetrization process. Ordination analysis of the weight matrix revealed a clear distinction between the two species. Multivariate test run on the weight matrix for A. neuquensis and A. riolimayana was highly significant (P < 0.0001). Females and males of the two species differ significantly (P < 0.0001). Females of A. neuquensis and A. riolimayana present a wider posterior region, probably to carry eggs and juveniles. The first relative warp clearly indicates a difference in the shape of crabs inhabiting rivers vs. those living in lakes (P < 0.0001). Lake specimens show a more compact rostrum than river individuals. This is probably associated with the difference in the dynamics of both systems. The shape of A. neuquensis in allopatric populations appears to be similar to the shape of A. riolimayana, while sympatric populations appear much closer to the "typical" A. neuquensis shape. Thus, allopatric populations appear in some way to expand their shape toward A. riolimayana.