Nereis Linnaeus, 1758

Type species. Nereis pelagica Linnaeus, 1758

Remarks. Bakken et al. (2022) and Wilson et al. (2023) developed a comprehensive diagnosis of the genus, which is followed in the present study. However, Nereis is a broadly heterogeneous genus, far from being solved, as no attempts have been made to define it accurately, and species richness continues to increase. Informal groupings have been proposed elsewhere (see Salazar-Vallejo et al. 2021), where a single member is listed and size-dependent features are used; nevertheless, this approach may result in troublesome designations (see Discussion).