Conservation genetics of the endemic Azorean slug Plutonia atlantica (Mollusca, Pulmonata)

Fifty-six specimens of the rare and endangered, endemic Azorean carnivorous slug, Plutonia atlantica, were surveyed for variation at 13 putative alloz yme loci in eight populations from three islands. Genotypic proportions sho wed no significant deviations from Hardy-Weinberg equilibrium expectations and average observed and expected heterozygosity values were H-o = 0.109 an d H-e = 0.118, At nearly all loci there were significant allele frequency d ifferences between populations. Hierarchical F-statistics, genetic distance s (identities), allelic distributions, and an independent analysis of isoel ectric focused esterase profiles, suggested that genetic variation in P. at lantica is geographically structured, i.e. within the island of Sao Miguel (Tronqueira region vs the remainder of the island), between islands and bet ween island groups (Faial/Pico vs. Sao Miguel). Genetic distances between p opulations from any of these geographic units were typical for interspecifi c comparisons. Therefore, it was concluded that conservation efforts in P. atlantica should recognize at least four management units (Faial, Pico, Tro nqueira in Sao Miguel and the remainder of Sao Miguel), in order to effecti vely preserve the currently known genetic diversity in this species. How fa r these management units represent evolutionarily significant units or even different taxa remains to be investigated. (C) 2000 Elsevier Science Ltd. All rights reserved.