''Arctonoe'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of worms in the family Polynoidae. They are commonly known as "scale worms". Members of this genus predominantly occur in shallow (50 metres or less) waters of the north-eastern Pacific Ocean and often live as commensals of other marine invertebrates, frequently

echinoderms An echinoderm () is any animal of the phylum Echinodermata (), which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies". While bilaterally symmetrical as larv ...

but sometimes

molluscs Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

or other

polychaetes Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are m ...

Description

Arctonoe have long bodies, with 100 or more segments and numerous pairs of smooth translucent scales ( elytra) on several of the segments. The first segment ( prostomium), which contains the mouth, is rounded and smooth; on its side it has antennae pointing away from the body. Parapodia are found along the body with both dorsal (notopodial) and ventral (neuropodial)

acicula Acicula (: aciculum) are strong, stout internal chaeta A chaeta or cheta (; ) is a chitinous bristle or seta found on annelid worms, although the term is also frequently used to describe similar structures in other invertebrates such as art ...

penetrating

epidermis The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermal layer provides a barrier to infection from environmental pathogens and regulates the ...

. The notochaetae are few in number and more slender than the neurochaetae both notochaetae and neurochaetae have minutely notched tips (see Hanley, 1989 for detailed diagnosis).

Species

The following species are recognised in the genus ''Arctonoe'': *'' Arctonoe fragilis'' (Baird, 1863) *'' Arctonoe pulchra'' (Johnson, 1897) *'' Arctonoe vittata'' (Grube, 1855)

References

{{Authority control Polychaete genera Phyllodocida