CHARACTERISATION OF AUSTROPOTAMOBIUS ITALICUS (FAXON,1914) POPULATIONS IN A CENTRAL SPAIN AREA

摘要

Crayfish Austropotamobius italicus (Faxon) populations in the province of Cuenca have been periodically monitored with different methodologies, intensity and success since the major outbreaks of crayfish plague which took place during the mid-1980’s. During 2000 summer a province-wide sampling program was carried using different sampling strategies. Information about basin characteristics, habitat and crayfish populations was collected. A total of 262 sites within the known or suspected area inhabited by the species were surveyed. A total of 39 populations were found. Nearly 40% of the populations come from known stocking actions carried by the Environmental Agency for the last twenty years. The populations are found in headwater creeks, are very small, and are usually isolated from the rest of the catchment. Differences between sites with and without A. italicus populations were examined. Although its number has not declined sharply during the last decade, several risk factors have been identified.