Distribución de los coleópteros acuáticos (Insecta, Coleóptera) en dos cuencas del sur de la P. Ibérica. Relaciones con algunos factores del medio

Abstract

Fauna of the extreme South of the Iberian Peninsula shows a high proportion of endemic species. Here, Guadalete and Guadairariver basins are placed. Coleoptera (larvas and adults) of the headwaters of these two basins have been studied for one annual cycle andthe factores of the environment relationed with them. Salinity (measured as conductivity. sulphate and chloride), flow velocity andaltitude were the main parameters that explained the species distribution. Potamorzectes cerisy, Ochthebius spp, Deroaectrs fairmriirei,Yola bicc~rinata,Berosus hispanic~ls,Laccobilrs atrocephalus and Laccobius sp were the most halophilic species. The taxa that showna preference towards high altitude and low levels of salinity were Gyrirzus dejeani, Hydroporus basinotatus, Hydraerza cc~ppta,Elrnismaugetii and Riolus subviolaceus. Temporality of the streams was a impediment for some species to establish in. Species ables to develop in environmcnts of bothtemporary or semipermanent and very saline waters were Yola bicarinata, Deronectesfairmairei, Berosus hisparzicus and h c c o b i ~ usp.