Abstract
Available studies of the earthworm fauna of Corsica reported a total of 36 species, but this regional diversity is probably underestimated considering the relatively modest sampling efforts achieved so far. We conducted a sampling campaign in the context of the program “Our Planet Reviewed”, with the aim to increase sampling coverage and to analyze already known regional diversity with a combination of classical morpho-anatomic characters and DNA barcoding. We sampled a total of 31 locations, and identified 22 previously recorded species and eight new citations belonging to the families Acanthodrilidae Claus, 1880, Hormogastridae Michaelsen, 1900 and Lumbricidae Rafinesque- Schmaltz, 1815. We obtained 525 COI barcodes which clustered into 48 genetic lineages, highlight- ing the importance of molecular techniques for earthworm diversity surveys. Of these lineages, ten are supported by multiple lines of evidence and will be described in a forthcoming taxonomy paper as species new to science. Biogeographical affinities of the identified species showed a lower rate of cosmopolitan species compared to other Mediterranean islands, a certain degree of affinity with Italy and Sardinia, and a high rate of endemism (which could be mirrored by the Balearic Islands and Sardinia). Comparative phylogeographic analyses are needed to understand the history of coloniza- tion and diversification of earthworms on Mediterranean islands, and to investigate the drivers that shaped differences in their diversity.