Chaetozone setosa Malmgren 1867

The time of spawning varies greatly in different areas. Females with ripe eggs have been observed from May until autumn. Like all cirratulids, this species has non-pelagic larvae. Its life span does not exceed 2 years. C. setosa leads a sedentary life within the sediment and also lives in empty burrows of other polychaetes. The members of the family Cirratulidae primarily are deposit feeders that are mainly non-selective, but may be selective as in the case of C. setosa (Hartmann-Schröder, 1971; Wolff, 1973; Curtis, 1977; Fauchald & Jumars, 1979; Christie, 1985; Hily, 1987).

Chaetozone setosa is readily distinguished from most related species by having a separate achaetous segment anterior to setiger 1 that bears the first pair of branchiae in combination with an enlarged dorsal swelling or crest on the peristomium. In addition, acicular spines of C. setosa begin in the posterior third of the body and have fully developed cinctures in the far posterior parapodia with 22?24 spines on each side (Blake [and Petersen] 2015:505

Gulf of St. Lawrence (unspecified region), lower St. Lawrence estuary, Saguenay Fjord; Prince Edward Island (from the northern tip of Miscou Island, N.B. to Cape Breton Island south of Cheticamp, including the Northumberland Strait and Georges Bay to the Canso Strait causeway); Cobscook Bay to Cape Hatteras

Chaetozone setosa is limited to Arctic and subarctic areas around Spitsbergen, other areas of northern Europe, and East Greenland in shelf depths of 30?110 m. World occurrence records and distribution statements for locations outside this area require re-evaluation