The polychaetes of the family Cirratulidae (Annelida) are common inhabitants in continental shelf benthic environments and considered an important group of organisms in environmental monitoring surveys. The family represents a taxonomic and systematic

Chaetozone setosa Malmgren, 1867 is commonly recorded as present in soft sediments from the intertidal zone to the deep sea from many localities worldwide. The genus was not defined by Malmgren, 1867 in his description of Chaetozone n. gen. and setosa

Using molecular markers and species delimitation analyses, a high diversity of bi-tentaculate Cirratulidae was discovered from the North-East Atlantic. Five new species are described: Chaetozone pseudosetosasp. nov., Chaetozone quintasp. nov., Chaetozone

The Chaetozone populations studied live under various conditions of organic enrichment, but in only one type of sediment (sandy mud). Each population variable is related to the density and individual mean weight (IMW). The optimal ecological area is defined