Paumotella takemoana Chamberlin, 1919

Ten Hove, Harry A. & Kupriyanova, Elena K., 2009, Taxonomy of Serpulidae (Annelida, Polychaeta): The state of affairs, Zootaxa 2036, pp. 1-126 : 72

Paumotella takemoana Chamberlin, 1919 , French Polynesia, Paumotu Archipelago.

Paumotella takemoana Chamberlin, 1919: 481–483 , pl. 78 figs 1–5; Southward, 1963: 586 (in key only); Fauchald, 1977: 145 (opercular peduncle with wings); Uchida, 1978: 71–72 (associated with Vermiliopsis ).

Material studied. French Polynesia, Paumotu Archipelago , Makemo, coral, at bottom of lagoon, 24 m (13 fm), R/V “Albatross” E. Pac. Exp. 1899–1900 ident. by Chamberlin (further details not present in internet list of stations) (holotype, USNM 19432; 2 slides (schizotypes) MCZ) .

Description. TUBE: absent, and not described by Chamberlin either.

BRANCHIAE: each lobe with 20–21 branchial radioles, arranged in semi-circles, not connected by branchial membrane. Radioles too convoluted to observe details of pinnules, terminal filament long. Branchial eyes not observed. Stylodes absent. Pair of mouth palps present.

PEDUNCLE: smooth, flattened circular in cross section, inserted just below left branchial lobe, covering base of 4–5 radioles. A single lateral wing along proximal 2/3 rds of peduncle ( Fig. 51E), exactly like figured for Vermiliopsis leptochaeta Pillai, 1971 ; showing clear constriction just below ampulla. Pseudoperculum absent.

OPERCULUM: globular to inverse conical with a distal slightly concave chitinous endplate, with smooth margin, and with flat central area without further ornamentation ( Fig. 51E). Length of operculum and peduncle 4–5 mm; opercular bulb 1.4 mm, width 1.8 mm.

COLLAR and thoracic membranes: collar high, with entire edge; deep incision between ventral and lateral collar lobes, the latter continuous with thoracic membranes, ending between chaetiger 4 and 5. Tonguelets between ventral and lateral collar lobes absent. Internal pockets in thoracic membranes and wartlike protuberances of collar chaetiger as in Floriprotis absent.

THORAX: with collar chaetiger, and 6 uncinigerous chaetigers. Pair of prostomial eyes not observed. Collar chaetae broken off, but according to Chamberlin they are limbate, of two sizes. Subsequent chaetae hooded (limbate), of two sizes. Apomatus chaetae occur in addition as well, both in slides of the type (MCZ) as well as in rest of holotype (contrary to Chamberlin’s description, and Fauchald (1977). Uncini along entire thorax saw-shaped, with 12 curved teeth and rounded peg. Thoracic uncinigerous tori gradually approaching one another posteriorly, forming a triangular depression on the ventral side of the thorax.

ABDOMEN: abdominal chaetigers 56, anterior three achaetigerous. Uncini rasp-shaped, with peg and 10 teeth in profile, 2–3 teeth in a row. Chaetae faintly curved, rounded acute aciculae, 3–4 per bundle. Long capillary chaetae present in 10–15 posterior chaetigers, broken, thus extent not entirely clear. Pygidium clearly bilobed. Posterior glandular pad absent.

Size: length up to 23.5 mm. Width of thorax 2.1 mm. Branchiae and operculum accounting for 1/6 of entire length.

Colour: the general colour is brownish yellow, with the parapodial processes paler. The thoracic collar is transparent. The branchiae yellow. Operculum yellow, with the rim black ( Chamberlin 1919: 482).

Ecology: no data except for those in label: coral, at bottom of lagoon, 24 m.

Remarks. Chamberlin´s original label gives as locality “Takemo”, hence the specific name of the taxon; this mistake already was corrected in his paper to the atoll of Makemo. From the fact that Fauchald (1977: 145) attributes wings to the opercular peduncle, a character not mentioned by Chamberlin, we infer that he probably saw the holotype. But for the presence of the absolutely unique abdominal chaetae the taxon could easily be mistaken for a species of the genus Vermiliopsis . Uchida (1978: 71–72) also associates the genus tentatively with Vermiliopsis sensu lato (his subfamily Vermiliopsinae ). Possible relationship will be discussed in (a) forthcoming paper(s) by us.