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

Fifty-six specimens of the rare and endangered, endemic Azorean carnivorous slug, Plutonia atlantica, were surveyed for variation at 13 putative allozyme loci in eight populations from three islands. Genotypic proportions showed no significant deviations from Hardy–Weinberg equilibrium expectations and average observed and expected heterozygosity values were Ho=0.109 and He=0.118. At nearly all loci there were significant allele frequency differences between populations. Hierarchical F-statistics, genetic distances (identities), allelic distributions, and an independent analysis of isoelectric focused esterase profiles, suggested that genetic variation in P. atlantica is geographically structured, i.e. within the island of São Miguel (Tronqueira region vs the remainder of the island), between islands and between island groups (Faial/Pico vs. São Miguel). Genetic distances between populations from any of these geographic units were typical for interspecific comparisons. Therefore, it was concluded that conservation efforts in P. atlantica should recognize at least four management units (Faial, Pico, Tronqueira in São Miguel and the remainder of São Miguel), in order to effectively preserve the currently known genetic diversity in this species. How far these management units represent evolutionarily significant units or even different taxa remains to be investigated.