Patterns of endemism in riverine fish of the Northern Hemisphere

Authors

  • T. Oberdorff,

    1. Mus?ƒ??um national d’histoire naturelle, Laboratoire d’Ichtyologie G?ƒ??n?ƒ??rale et Appliqu?ƒ??e, 43 rue Cuvier, F-75231, Paris Cedex 05, France.
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  • S. Lek,

    1. C.N.R.S.-U.M.R. 5576, C.E.S.A.C., Universit?ƒ?? Paul Sabatier, B?ƒ??t. IVR3, 118 route de Narbonne, F-31062 Toulouse Cedex, France.
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  • J.-F. Gu?ƒ??gan

    1. CEPM/UMR CNRS-IRD 9926, IRD, BP 5045, 911 rue du Val de Montferrard, Parc Agropolis, F-34032 Montpellier Cedex 01, France.
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ThierryOberdorff E-mail: oberdorf@mnhn.fr.

Abstract

Loss of endemic species represents a symptom of general degrading ecosystem conditions that is the indirect result of biodiversity alteration. Here, we developed a predictive model relating species richness of endemic riverine fishes to measured biological, climatic, and historical variables using data from 118 rivers distributed all over the Northern Hemisphere. In a minimally adequate multiple general least square model, total riverine fish species richness, historical biogeography (Pleistocene glaciations), and comtemporary climate accounted for 63% of the variability in endemic species richness; the strongest correlate being riverine fish species richness. Our findings suggest that (i) endemism and richness patterns are generally similar (fish diversity “hot-spots” areas sustain higher endemic species richness); (ii) glaciation in the Pleistocene have had a significant negative influence on endemic species richness in the more septentrional areas; and (iii) certain basins situated in desertic areas (subtropical dry-zone of deserts) have unusually high numbers of endemics. These last areas should not be overshadowed when setting conservation priorities.

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