Continental shelf

Phylogenetic tree

Clitellata

Evolutionary biology

Biology

Zoology

Gene

Species complex

Genus

Habitat

Composite material

Ecology

Materials science

Range (aeronautics)

Annelid

Fishery

Biochemistry

Taxon

Sympatry

PLoS ONE

We investigate mitochondrial (COI, 16S rDNA) and nuclear (ITS2, 28S rDNA) genetic structure of North East Atlantic lineages of Terebellides, a genus of sedentary annelids mainly inhabiting continental shelf and slope sediments. We demonstrate the presence of more than 25 species of which only seven are formally described. Species boundaries are determined with molecular data using a broad range of analytical methods. Many of the new species are common and wide spread, and the majority of the species are found in sympatry with several other species in the complex. Being one of the most regularly encountered annelid taxa in the North East Atlantic, it is more likely to find an undescribed species of Terebellides than a described one.

A mega-cryptic species complex hidden among one of the most common annelids in the North East Atlantic