Cryptic speciation at organic-rich marine habitats: a new bacteriovore annelid from whale-fall and fish farms in the North-East Atlantic

Abstract

Vigtorniella ardabilia sp. nov., a new chrysopetalid annelid, is described from a whale-fall in Sweden and from sediment samples collected beneath fish farms in Norway. The new Vigtorniella species is morphologically almost identical to Vigtorniella flokati from whale-falls in the Pacific Ocean, although molecular evidence from four genes shows that they are different species. Population genetic structure and phylogenetic relationships of V. ardabilia sp. nov. were assessed using molecular data from the nuclear genes 18S and 28S, and the mitochondrial 16S and cytochrome c oxidase subunit I (COI). High levels of gene flow are reported between contrasting organic-rich environments in the North Atlantic (fish farms and whale-fall). Observations of feeding biology and habitat suggest that V. ardabilia specializes on bacterial mats, rather than on whale-falls, although the two species of Vigtorniella for which data were available show very different feeding behaviours. Our results further showed an unexpectedly low divergence rate in Vigtorniella for the mitochondrial markers, suggesting stabilizing selection. Analyses carried out with parsimony, maximum likelihood, and MrBayes all placed the genus Vigtorniella as sister group to Dysponetus, suggesting a close evolutionary link to sediment-dwelling fauna.

Comparative Composition, Diversity and Trophic Ecology of Sediment Macrofauna at Vents, Seeps and Organic Falls

“…Some of the dorvilleid species at whale falls (including species in the genera Ophryotrocha, Parougia and Schistomeringos ), can occur in abundance at wood falls and seeps [17], [32], [93]. Most dominant taxa present at these islands are microbial-mat grazing and predacious polychaetes as well as opportunistic cumaceans [17].…”

A new species of Glyceridae (Annelida: “Polychaeta”) recovered from organic substrate experiments at cold seeps in the eastern Mediterranean Sea

“…Even though these organic falls are unpredictable in time and space, they are yet quickly located and colonized by specialized opportunistic fauna (e.g. Smith et al 1989;Dahlgren et al 2004;Rouse et al 2004;Pleijel et al 2008;Wiklund et al 2009;Gaudron et al 2010) and can quickly develop into hot spots of biodiversity in deep-sea environments . Intensive local degradation processes can lead to reducing conditions and high sulphide concentrations Laurent et al 2009;Treude et al 2009).…”

Antonbruunia sociabilis sp. nov. (Annelida: Antonbruunidae) associated with the chemosynthetic deep-sea bivalve Thyasira scotiae Oliver & Drewery, 2014, and a re-examination of the systematic affinities of Antonbruunidae

“…There is no evidence as yet that the polychaetes themselves are chemosymbiotic. It is of interest that one of the three species of Vigtorniella Kiseleva, 1996 (Calamyzinae), V. ardabilia Wiklund et al, 2009, has been observed feeding on giant filamentous bacterial mats associated with whale bones and also likely feeds on bacterial mats under fish cages. Another, V. zaikai (Kiseleva, 1992) inhabits sulphide-rich sediments.…”