New species and records of deep-water Cirratulidae (Polychaeta) from off Northern California

Abstract

Polychaetes of the family Cirratulidae are among the most important macrofaunal invertebrates in deep-sea benthic communities off northern California. The genus Chaetozone includes several species that are among the dominant species in depths of 2400-3200 m. Four of the most common species of Chaetozone are described in this paper. Of these four species, only C. spinosa Moore, 1903 has been previously described. Three other species are new to science. C. brunnea, n. sp. has a short, triangular-shaped prostomium, brown body colour, and an enlarged “stomach” which distends the body in a characteristic pattern. C. allanotai, n. sp. has a unique methyl green staining pattern that provides a means to readily identify juveniles and fragmented adults. A third new species, C. palaea, n. sp has posterior spines that are unusually broad, providing a spectacular armature. These species are compared with the type species, C. setosa from the Arctic. New details concerning segmentation of the anterior end, morphology of the nuchal organs, and posterior spines, represent a suite of characters that, in combination, will be used in a phylogenetic analysis of cirratulid polychaetes.