Distribution of marine, benthic, shell bearing gastropods along the Norwegian coast

Abstract

Based on literature data and my extensive material from along the coast, the distribution of shell bearing marine, benthic gastropods known from Norwegian waters, is outlined. The geographic area covered goes down to c. 1200 m on the continental slope, and extends from the Swedish border in the south to the Russian border in the north-east. On the slope the distribution is restricted to an area east of 0°, and south of 72° N. Neither the North Sea nor the western ‘slope’ of the Norwegian Trench are included. Systematics and nomenclature follow Clemam (Check List of European Marine Mollusca) closely. The emphasis is on the distribution of each species within the designated area, but taxonomic and nomenclaturial problems are discussed wherever considered relevant. Altogether 365 species level taxa are included, of which 326 are considered as definitely belonging to the Norwegian fauna. The rest are recorded as doubtful, either because only empty shells have been found, or their confirmed distribution falls outside the limits here defined. Of the ‘species’ included, I consider at least 18 to be undescribed, while another 16 were described from Norwegian material after Høisæter (1986) was published. The northern distributional limit is extended for 47 species, while 11 species have received a new southern limit. Sixty six species have a generic name diferent from the one used in Høisæter (1986), while 35 species have another specific name. All changes are listed in the main part of the article, and references are given to the sources for the changes. Four faunal components are recognized: a slope component, species mainly found in negative temperatures on the continental slope, between 500 and 1200 m; an Arctic component, species in Norway almost exclusively found in East Finnmark; a group of species in Norway found only or mainly on the Skagerrak coast or in Oslofjorden; and finally the main group found along most of the coast.