Phragmatopoma, MORCH, 1863

Capa, María, Hutchings, Pat & Peart, Rachael, 2012, Systematic revision of Sabellariidae (Polychaeta) and their relationships with other polychaetes using morphological and DNA sequence data, Zoological Journal of the Linnean Society 164 (2), pp. 245-284 : 268

PHRAGMATOPOMA MÖRCH, 1863

Phragmatopoma Mörch, 1863: 442 .

Type species: Phragmatopoma caudata Mörch, 1863 . Type locality: West Indies .

Diagnosis: Inner paleae arranged in two concentric rows, pointing inwards to the centre of the opercular disc, with strongly geniculate and convex blades, middle paleae almost covering innermost ones.

Description: Operculum longer than wide, with lobes completely fused to each other, although shallow mid ventral indentation sometimes present in proximal end. Distal disc flat and perpendicular to longitudinal axis. Numerous digitiform and long opercular papillae around its perimeter. Outer paleae numerous, arranged in semicircles; geniculate, with flat blades, smooth lateral margins, distal denticles, and a midline plume. Inner opercular paleae giving the appearance of two concentric rows, directed inwards, with paleae strongly geniculate with convex blades and pointed tips directed inwards, middle paleae almost covering innermost paleae. Nuchal spines absent. Compound (branching) tentacular filaments arranged in series of rows; buccal flaps absent. Palps similar in length to operculum. Conspicuous median organ absent. Neuropodia of segment 1 with one conical cirri on both sides of building organ and capillary chaetae. Segment 2 with two pairs of triangular-shaped lateral lobes. Thoracic branchiae present. Three parathoracic segments. Parathoracic notochaetae lanceolate and capillaries alternating; neurochaetae similar in shape but smaller. Abdominal branchiae present to posterior segments.

Remarks: Phragmatopoma , Neosabellaria , and Sabellaria share the arrangement of inner paleae in two concentric rows. Phragmatopoma and Neosabellaria are recovered as sister groups due to the complete fusion of operculum lobes. There are four recognized species in the genus, all forming large colonies and extensive reefs in the intertidal and shallow water areas (with the exception of P. californica found up to 200 m) with an amphiamerican distribution ( Kirtley, 1994). The type of P. caudata seems to be missing and the last person to see this material was Ehlers in 1901 ( Kirtley, 1994). Even though no type exists, Kirtley (1994) synonymizes several species with this type species which may be premature given the original brief description.