Pomatoleios Pixell, 1913

Ten Hove, Harry A. & Kupriyanova, Elena K., 2009, Taxonomy of Serpulidae (Annelida, Polychaeta): The state of affairs, Zootaxa 2036, pp. 1-126 : 77-78

31. Pomatoleios Pixell, 1913

( Fig. 36)

Type-species: Pomatoleios crosslandi Pixell, 1913 , junior synonym of Placostegus cariniferus var. kraussii Baird, 1865 Number of species: 1

Tube white or bluish, opaque, triangular in cross-section, with medial keel projecting into flap over the entrance. Granular overlay absent. Operculum inverse conical with flat calcareous plate; sometimes with talon projecting into opercular ampulla (best seen if operculum is cleared in glycerine). Peduncle thick, triangular in cross-section, with distal wings, without constriction, inserted almost medially, slightly left, covering base of up to five radioles. Pseudoperculum absent. Radioles arranged in semi-circles, up to 19 per lobe, connected by very high inter-radiolar membrane. Branchial eyes present (single ocelli visible in fresh material only). Stylodes absent. Mouth palps present. 6 thoracic chaetigerous segments (in juveniles 7). Collar with entire edge, tonguelets between ventral and lateral collar lobes present; thoracic membranes forming ventral apron. Collar chaetae absent (limbate ones present in juveniles only). Apomatus chaetae absent. Uncini saw-shaped with fairly numerous (10–11) teeth, anterior peg wide and blunt, gouged ( Fig. 36B). Triangular depression present. Abdominal chaetae true trumpet-shaped, abruptly bent, distally with two rows of denticles separated by a groove ( Fig. 36A). Achaetous anterior abdominal zone absent. Posterior capillary chaetae and posterior glandular pad absent.

Remarks. Opercular talons as reported by Pillai (1965 fig. 22H) and ten Hove (1973 fig. 43) are not consistenly mentioned (nor looked for) in the literature. Whether or not the presence of such a talon is a character distinguishing between populations or even taxa should be investigated.

Pomatoleios kraussii is widely distributed in the Indo-Pacific forming intertidal aggregations. The only difference between Pomatoceros and Pomatoleios is the more or less consistent lack of collar chaetae in the latter. However, collar chaetae may be present in juvenile specimens ( Zibrowius 1968a, Crisp 1977, ten Hove & Nishi 1996), and occasionally absent in Pomatoceros (e.g., 9 specimens from the Irish Sea, ZMA V.Pol. 3201) as well as in Spirobranchus (e.g., as Olga elegantissima Jones, 1962 ), thus this monotypic genus likely lacks a phylogenetic basis. See further remarks for Spirobranchus . SEM photos of Pomatoleios are published in Fiege & Sun (1999).

Pomatoleios kraussii ( Baird, 1865) , South Africa; widely distributed in the Indo-Pacific; Lessepsian migrant to the Levant Mediterranean.