''Antipathipolyeunoa'' is a genus of marine

annelids The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecolog ...

in the family

Polynoidae Polynoidae is a family of marine Polychaete worms known as "scale worms" due to the scale-like elytra on the dorsal surface. Almost 900 species are currently recognised belonging to 9 subfamilies and 167 genera. They are active hunters, but gene ...

(scale worms). The genus contains a single species, ''Antipathipolyeunoa nuttingi'', found in the

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...

at a depth of 91 metres.Pettibone, M.H. (1991). Polynoid polychaetes commensal with antipatharian corals. Proceedings of the Biological Society of Washington. 104(4): 714-726., available online at https://www.biodiversitylibrary.org/page/34809416

Description

Species of ''Antipathipolyeunoa'' have 82–84 segments and 40 pairs of

elytra An elytron (; ; , ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometimes alterna ...

; the elytra are large and cover the dorsum completely. Cephalic peaks are also present, and the neuropodia are with a subacicular process.

Description of ''Antipathipolyeunoa nuttingi''

Specifically, ''A. nuttingi'' has 82 segments and 40 pairs of

, with a nearly continuous reddish brown longitudinal dorsal pigmentation band with some spots at the base of the dorsal cirri and some midventral pigmentation. The lateral antennae are inserted ventrally (beneath the

prostomium The prostomium (From Ancient Greek, meaning "before the mouth"; plural: prostomia; sometimes also called the "acron") is the cephalized first body segment in an annelid worm's body at the anterior end. It is in front of (but does not include) t ...

and median antenna), and

notochaetae A chaeta or cheta (from Greek χαίτη “crest, mane, flowing hair"; plural: chaetae) is a chitinous bristle or seta found in annelid worms, (although the term is also frequently used to describe similar structures in other invertebrates such ...

are about as thick as

neurochaetae A chaeta or cheta (from Greek χαίτη “crest, mane, flowing hair"; plural: chaetae) is a chitinous bristle or seta found in annelid worms, (although the term is also frequently used to describe similar structures in other invertebrates such ...

. Bidentate neurochaetae are absent.

Taxonomic comments

''Antipathypolyeunoa'' is most similar to another long-bodied genus, '' Polyeunoa'', however ''Polyeunoa'' lacks the distinctive subacicular neuropodial process. '' Parahololepidella'' also has a subacicular neuropodial process but has 80 or more segments and 67 pairs of very small elytra which only cover the base of the parapodium.

Biology and ecology

''Antipathypolyeunoa'' is one of many genera in the family Polynoidae which have an obligate

commensal Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit fro ...

relationship with a host marine invertebrate. As the name suggests, ''Antipathypolyeunoa'' is associated with antipatharian corals (black corals or thorn corals), being found in hollow tubes in the main stems of the coral host. ''A. nuttingis host taxon is '' Antipathes tanacetum''.

References

{{Taxonbar, from1=Q42585122, from2=Q2476259 Phyllodocida Monotypic annelid genera Annelid genera