Biogeography and conservation of Iberian water beetles

An analysis is made of the main biogeographical trends and the conservation status of the aquatic Coleoptera from the Iberian peninsula. More than 600 species in 100 genera and 20 families are recognised, although knowledge of some of them is still scarce. Overall, the level of endemism is about 20%, with a highly uneven taxonomic distribution. Five main geographical regions are recognised based on geological and topographical criteria: Pyrenean, Cantabrian mountains, Hercynian, South East, and South West. These regions have a significantly distinct fauna when all species, species of the family Hydraenidae, all Iberian endemics, and Hydraenidae endemics are considered. For other groups this geographical division is not relevant, as the species follow a random distribution. The main biogeographical division is between the northern and the southern regions, with closer similarity between the Pyrenees and France, and between the South East and Morocco, than with other Iberian regions. The conservation status of the species included in the IUCN red list is reviewed. suggesting the exclusion of three species previously considered to be endangered or vulnerable, and the inclusion of two new species as vulnerable. The status of the rare species is discussed, with the distinction between local endemics, possible relict species, and species with discontinuous distributions due to habitat loss or habitat fragmentation. The habitats with the highest conservation value are medium altitude freshwater streams in the Hercynian mountains of central and western Iberia, the pre-Pyrenees and the Baetic cordilleras, together with saline streams in the South East and the central Ebro Valley. Some general guidelines are suggested for their preservation. (C) 2000 Elsevier Science Ltd. All rights reserved.