Some notes on reproductive biology and mating behaviour of Arion vulgaris Moquin-Tandon 1855 in Norway including a mating experiment with a hybrid of Arion rufus (Linnaeus 1758) x ater (Linnaeus 1758)

摘要

Arion vulgaris Moquin-Tandon 1855 (synonym Arion lusitanicus Mabille 1868) lias been spreading through Norway during the last 20 years. We present phenological and reproductive data from iuestern Norzvegian populations. Mating experiments under semi-natural conditions revealed a prolonged duration of copulation compared with other studies. In partner choice experiments using marked slugs we observed that remating occurred in this Arion species. For the first time, experimental evidence for mating between Arion rufus x ater (Linnaeus 1758) and A. vulgaris is reported which confirms other genetic and morphological studies suggesting low reproductive isolation within the larger Arion species complex. Moreover, even based on very preliminary experiments our data suggest a case for possible mitochondrial heteroplasmy in Arion.