Aspects of the trophic ecology of Xenopus laevis, an amphibian introduced in Chile Central, were analyzed

Abstract

The work was carried out in four areas inhabited by the species around Santiago of Chile: Laguna Batuco, Vertiente Cerros de Batuco, Cuesta de Ibacache and Antumapu (La Pintana). The physico chemical variables from these ecosystem s were studied and 111 specimens were captured. The body weights o f these amphibians were compared using means of a variance analysis. The niche breath and niche overlap were calculated and the niche superposition among the different areas was estimated. Xenopus laevis w as found in clean environments as well as in very transformed ones. The etarians structures revealed differences among localities (F3107 = 90,5; P menor que 0 ,001 ). However, in all of them the female weights were greater than the male ones (F , 109 = 4 0,2; P menor que 0 ,0 0 1 ), which suggest a definite sexual dimorphism. Niche amplitude were completely unequal among localities, as well as the diet com position in general. The consume of dipteran and the fresh water gastropod Pliysa sp. predominated. The larger females of this anuran species eat a large number of larvae from their own species. These observations demonstrate the high adaptative power of this exotic amphibian, as an important element which facilitates its colonization of the aquatic environments from Central Chile.