On the deep-sea Nephasoma species in the Eastern North Atlantic – a taxonomic guide

Abstract

Sipuncula is a relatively species-poor phylum that can play a considerable role in soft sediment benthic ecosystems. The ecological and geochemical influence of sipunculans can vary between species. However, identification of sipunculan species is often problematic. This article focuses on sipunculans collected in the Nordic Seas belonging to the genus Nephasoma, a common genus in deep-water collections. A review of Nephasoma taxonomic descriptions in eastern North Atlantic waters and a key to identifying sipunculans found in the region of deep Nordic Seas is provided.

Sipunculan fauna in the Pacific Arctic region: a significant component of benthic infaunal communities

“…The complex gallery burrows produced by this species, which can reach 30-50 cm deep in the sediment, and the associated rapid subduction of organic matter are of large importance in the deep sea ecosystems where burrowers are less common than on shelves (Romero-Wetzel 1987;Graf 1989;Shields and Kędra 2009). Although we have not found N. lilljeborgi in this study, and it has not been reported by other authors from the Pacific portion of the Arctic (Murina 1977;Cutler 1994), it is possible that it inhabits deeper portions of the northern Chukchi and Beaufort Seas, and well as the Arctic Basin, as it is an important component of Nordic Seas deep communities (Shields and Kędra 2009;Kędra and Shields 2011). However, more studies are needed in the Pacific sector deep sea to confirm its occurrence and function.…”

“…Species, like N. lilljeborgi and Nephasoma abyssorum, which are typical of Arctic deepsea communities ([1000 m, not sampled here; Kędra and Shields 2011) were not found in this study but are likely to inhabit the Arctic basins. Compared to the northern Bering (four species) and Chukchi (five species) Seas, the two species solely found in the Beaufort Sea seem to indicate an underestimation of Beaufort sipunculan species richness.…”

“…Also P. strombus is a common shelf Arctic species (Murina 1977;Murina and Sorensen 2004;Kędra and Włodarska-Kowalczuk 2008;Garbul and Anisimova 2012; this study). The deep Arctic Ocean, on the other hand, is primarily dominated by species of the genus Nephasoma (Murina 1977;Murina and Sorensen 2004;Kędra and Shields 2011) which, due to its burrowing activities, has important implications for organic matter distribution in the sediment and carbon turnover (RomeroWetzel 1987;Graf 1989;Shields and Kędra 2009). Thus, sipunculans, although species poor, should not be overlooked in Arctic ecological studies.…”

“…Most studies of sipunculans in the Arctic have been predominantly concentrated in the Atlantic sector of the Arctic: Greenland (Wesenberg-Lund 1934, 1937, 1938, Svalbard (Kędra and Murina 2007), and the deep Nordic Seas (Kędra and Shields 2011). The Pacific Arctic Region has received much less scientific attention in terms of sipunculan fauna (Murina 1977(Murina , 1985 Grebmeier in press).…”