Environmental features drive lineage diversification in the Aricidea assimilis species complex (Annelida, Paraonidae) in the Mediterranean Sea

Individuals identified as Aricidea assimilis Tebble, 1959 were collected from ten localities across the Mediterranean Sea from 0.5 to 225 m depth in order to have a wide coverage of the species habitats and geographic range and to assess the effects of environmental factors and biogeographical barriers on molecular and morphological diversity. Two mitochondrial and one nuclear markers were used to reconstruct phylogenetic relationships and test the occurrence of cryptic species. We observed two highly divergent lineages, one including all individuals from shallow, sandy environments (