Anotochaetonoe, Britayev & Martin, 2005

Britayev, T. A. & Martin, D., 2005, Scale-worms (Polychaeta, Polynoidae) associated with chaetopterid worms (Polychaeta, Chaetopteridae), with description of a new genus and species, Journal of Natural History 39 (48), pp. 4081-4099 : 4083

Genus Anotochaetonoe gen. nov.

Type species

Anotochaetonoe michelbhaudi , new species, by original designation herein. Gender: feminine.

Diagnosis

Body truncated anteriorly and gradually tapering posteriorly, convex dorsally and flattened ventrally, with up to 20 pairs of elytra and up to 47 chaetigers. Elytra on prominent elytrophores, on segments 2, 4, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 26, 29, 32, 34, 37, 40, 43, 46, reaching the end of body. Dorsal surface without prominent tubercles.

Prostomium bilobed, wider than long, without cephalic peaks, with two palps and three antennae. Ceratophore of median antenna inserted in the anterior notch, ceratophores of lateral antennae inserted termino-ventrally on distal end of prostomium, not converging mid-ventrally (arranged in parallel). Tentaculophores lateral to the prostomium, achaetous, each with one pair of dorsal and ventral tentacular cirri. Buccal segment without nuchal fold; with a prominent conical facial tubercle; ventral buccal cirri longer than following ones. Proboscis with nine pairs of papillae and two pairs of jaws.

Parapodia relatively long, sub-biramous, without notochaetae. Notopodia achaetous, reduced to digitiform protrusion. Neuropodia deeply incised dorsally and ventrally, with longer subtriangular prechaetal lobes, and shorter, distally rounded postchaetal lobes; tips of acicula not penetrating epidermis. Neurochaetae straight to falcate, with rows of spines distally and unidentate knob-like or bidentate tip. Dorsal cirri present on segments without elytra; cirrophores short, cylindrical; styles smooth, tapering gradually to filiform tips, with a marked alternation in length. Ventral cirri short, gradually tapering, smooth. Globular ciliated papillae present ventrally between ventral cirri and basis of neuropodia. Pygidium with terminal anus and long, smooth anal cirri. Known only as symbionts of chaetopterid worms.

Etymology

From Latin, a (without), notochaetae, plus noe, to refer to a polynoid worm without notochaetae.

Remarks

There are several polynoid genera without notochaetae, most of them belonging to the subfamily Lepidastheniinae ( Barnich and Fiege 2004) . Among them, only Alentiana is close to Anotochaetonoe in having fewer than 50 segments. However, they differ in: (1) the arrangement of elytra in posterior part of the body: on chaetigers 23, 26, 29, 32, 34, 37… ( Anotochaetonoe ) or 23, 26, 29, 32, 34, 36, 37… ( Alentiana ); (2) in the shape of neuropodia: long, with longer subtriangular prechaetal lobes and shorter, distally rounded postchaetal lobes ( Anotochaetonoe ) or relatively short with both lobes rounded ( Alentiana ). Anotochaetonoe resembles the long-bodied genus Telolepidasthenia in the arrangement of elytra on segments 23, 26, 29, 32, 34, 37; in the presence of globular ciliated papillae on the lower margin of neuropodia; and in their life habits as symbionts with chaetopterid worms. However in the new genus, the number of chaetigers is fewer than 50, neuropodia have longer, subtriangular prechaetal lobes and shorter, distally rounded postchaetal lobes, and neurochaetae have unidentate and bidentate tips, while Telolepidasthenia has more than 60 chaetigers, neuropodia with both lobes rounded and neurochaetae with entire tips.