Répartition des oligochètes lacustres du massif de Néouvielle (Hautes-Pyrénées) avec la description de Peloscolex pyrenaicus, n. sp

Abstract

The lakes of the mountain range of Néouvielle (High Pyrenees) contain about twenty species of oligochaetes, chiefly ubiquitous and holarctic species. A new species is described, Peloscolex pyrenaicus, which is biogeographically and ecologically close to Peloscolex velutinus, and is frequent in the deeper zone of subalpine lakes. Quantitatively, the Tubificidae form the highest mean density in the population, followed in order by the Naididae, Enchytraeidae and Lumbriculidae. The percentages of similarity between the communities originating from the different stations and the interspecific indices of association have been calculated. The oligochaete communities are arranged in a series as a function of two gradients, altitude and depth. This series, conditioned by climatic and edaphic factors, affects the qualitative and especially the quantitative distribution of the benthic communities. © 1974 Masson.