Pomatostegus Schmarda, 1861

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

32. Pomatostegus Schmarda, 1861

( Fig. 37)

Type-species: Pomatostegus macrosoma Schmarda, 1861 , junior synonym of Terebella stellata Abildgaard, 1789 Number of species: 3

Tube white, opaque, semi-circular to roughly triangular in cross-section, with up to 5 longitudinal keels; granular overlay absent. Operculum a very flat ampulla covered with chitinous disk bearing a column with several serrated disks alternating with circlets of spines proximally and closely applied to each disk. Peduncle flatly triangular in cross-section with broad latero-distal wings along its entire length; inserted to the left or right at the basis of the branchial lobe; from the fact that the first and second radiole separated by the base of the peduncle, it is inferred that it is derived from the second normal radiole. Constriction absent. Pseudoperculum absent. Arrangement of radioles in (semi-)circles, up to 90 per lobe. Inter-radiolar membrane present. Branchial eyes present. Stylodes absent. Mouth palps absent. 7 thoracic chaetigerous segments. Collar tri- to penta-lobed, well developed with an entire smooth margin. Tonguelets absent. Thoracic membranes short, ending just posterior to the second row of uncini (segment 3). Collar chaetae Spirobranchus - type, with basal pilose fin and distal blade, and limbate ( Fig. 37B). Apomatus chaetae present ( Fig. 37E). Thoracic uncini saw-shaped, with 9–13 teeth, anterior peg blunt ( Fig. 37C). Thoracic tori meet ventrally in larger specimens; in juveniles the ventral space between thoracic tori narrowing towards last rows that almost fused, leaving a triangular depression. Abdominal chaetae flat narrow geniculate, with long blade ( Fig. 37F). Abdominal uncini smaller than thoracic ones, with about 8 teeth in profile, 3 teeth in a row ( Fig. 37D). Achaetous anterior abdominal zone absent. Long posterior capillary chaetae absent, but posterior chaetae longer. Posterior glandular pad absent.

Remarks. According to the recent literature there is but a single circumtropical species, Pomatostegus stellatus . However, an unpublished study by P. Valentijn (former student to HAtH, University Utrecht), reinstigated two species regarded to be synonymous with the type-species to full specific rank: P. actinoceras , from the Indo-West Pacific Region, and P. krøyeri , from tropical Pacific America, leaving a tropical Atlantic distribution only for P. stellatus . The latter taxon has been recorded from Atlantic Africa by Augener (1918), Amoureux (1973), and Zibrowius (1973b), however, the single specimen studied from Western Africa by Valentijn and ten Hove could not be attributed with certainty to either P. actinoceras (likely) or P. stellatus (less likely).

1. Pomatostegus actinoceras Mörch, 1863 , Indo-West Pacific,?Western Africa; generally synonymised with P.stellatus

2. Pomatostegus krøyeri Mörch, 1863 , tropical Pacific America; generally synonymised with P. stellatus

3. Pomatostegus stellatus ( Abildgaard, 1789) , West Indies; Caribbean; usually including preceding 2 species.