New earthworm records from the Caspian Hyrcanian Forests of Iran (Oligochaeta: Megadrili).

Earthworms are the most important soil invertebrates worldwide, in terms of biomass and effects on soil processes. In this study, 21 earthworm species, including four new records were identified from Caspian Hyrcanian Forests (North of Iran). Four species; Criodrilus lacuum, Lumbricus rubellus, Metaphire californica, and Octodrilus transpadanus and the family Criodrilidae are reported for the first time. Previous studies have identified 31 earthworm species belonging to 14 genera and three families (Lumbricidae, Acanthodrilidae, and Megascolecidae) in Iran; therefore, these new records increase the number of earthworm species to a total of 35.