Parasitism of the leech, Batracobdella algira (MOQUIN-TANDON, 1846), on Sardinian cave salamanders (Genus Hydromantes) (Caudata: Plethodontidae)

Very little information is available on relationships between Sardinian cave salamanders (genus Hydro mantes; subgenera Speleomantes and Atylodes) and other cave-dwelling organisms. Cave salamanders are known to be parasitized by the leech, Batracobdella algira, but no information exists on the prevalence of this parasite on cave salamanders or the factors that promote it. The authors surveyed 55 cavities covering the range of H. flavus, H genei, H imperialis, H sarrabusensis and H supramontis, analyzed the spatial variation of parasitism by B. algira, and detected the leech in H flavus, H genei and H imperialis. Infestation was low for all species (prevalence < 3 %) except H flavus (9 %). Prevalences showed strong spatial autocorrelation, and were unrelated to cave abiotic features. Large individuals were the most frequently parasitized. Moreover, predation on H sarrabusensis by the spider Tegenaria sp. was observed. The relationships between cave salamanders and B. algira show a complex pattern, with strong heterogeneity among species, populations and individuals.