U.R. 131 Institut de Recherche pour le Développement (IRD), 43 Bd du 11 novembre 1918, Villeurbanne, France.
J Fish Biol. 2009 Feb;74(3):502-20. doi: 10.1111/j.1095-8649.2008.02140.x.
This study explores the relationship between morphology and diet in four Andean killifishes (Orestias) from Lake Titicaca that are known to differ in habitat use. Species that fed preferentially on amphipods (Orestias albus) or molluscs (Orestias luteus) separated in multivariate space from other species that feed on cladocera and algae (Orestias agassii and Orestias jussiei). Generally, specimens feeding on cladocera were characterized by a short, blunt nose with a small mouth; whereas, specimens feeding on amphipods exhibited a long snout with a large mouth. Specimens including molluscs in their diet tended to have a larger posterior part of the head and the larger opercles than others; while the occurrence of substratum in gut content was generally related to a short but deep head. The present analysis suggests that the littoral O. jussiei has an intermediate phenotype and diet between the pelagic (O. agassii) and benthic (O. albus and O. luteus) species. Results suggest that resource partitioning was occurring and that several morphological traits relate to characteristics of the diet, and it is inferred that the benthic, the pelagic and the littoral zones in the lake host different prey communities constituting distinct adaptive landscapes.
本研究探讨了在特提斯湖的四种安第斯脂鲤（Orestias）中形态与饮食之间的关系，这些鱼类因栖息地的使用而有所不同。优先以端足类（Orestias albus）或软体动物（Orestias luteus）为食的物种与以桡足类和藻类（Orestias agassii 和 Orestias jussiei）为食的其他物种在多维空间中分离。通常，以桡足类为食的标本具有短而钝的鼻子和小嘴；而以端足类为食的标本则具有长而大的口鼻。在其饮食中包括软体动物的标本的头部后部和较大的鳃盖通常比其他标本更大；而肠道内容物中基质的出现通常与短而深的头部有关。目前的分析表明，湖岸带的 O. jussiei 具有介于浮游（O. agassii）和底栖（O. albus 和 O. luteus）物种之间的中间表型和饮食。结果表明，资源分配正在发生，并且几种形态特征与饮食特征有关，并且可以推断，湖泊的底栖、浮游和湖岸带栖息着不同的猎物群落，构成了不同的适应景观。
