Sobre la presència de "Ferrissia" i "Acroloxus" "(Gastropoda: Basommatophora)" als Països Catalans

Abstract

The genus Ferrissia (F. Ancylidae) and Acroloxus (F. Acroloxidae) have been frequently confused, or simply undetected because of their size and limnic habitat. They are represented in the Catalan Countries (Catalonia, Valencia and the Balearic Islands) by Ferrissia wautieri and Acroloxus lacustris. A description of both species and their geographical and ecological distribution follows: F. Wautieri appears to be ubiquitous on the continent, in calm or, less frequently, moderately flowing waters, in lowlands and hills; A. Lacustris lives in freshwater marshes or wide placid, highly vegetated canals in the northeastern part of Catalonia, though subfossil recordings have been made further south. This is the first recording of F. Wautieri in the Iberian Peninsula.
We suggest that there may exist competition phenomena between freshwater limpets: Ancylus fluviatilis (Muller, 1774) lives in well oxygenated running water, Acroloxus (s.s.) lacustris (Linnaeus, 1753) predominates in permanent lentic environments of Eurosiberian affinity, and Ferrissia (Pettancylus) wautieri (Mirolli, 1960) extends throughout the Mediterranean regions, especially in casual waters, displaying the opportunism of a good colonizing species, due to its ability to form a septum to resist adverse conditions and because its reproduction is accomplished almost exclusively by self-fertilisation.