Notopygos caribea Yáñez-Rivera & Carrera-Parra 2012

Holotype (ECOSUR 0145) mature male, complete, with 30 chaetigers, 3 cm total length, 1 cm wide. Body fusiform, orange to light brown, with reddish-brown branchiae. Pigmentation pattern complex, triangular and rhomboid forms covering the dorsum (Figs 2C, 4F). Prostomium semicircular with four eyes in pigmented strip, anterior eyes twice size of posterior ones (Fig. 2A). Median antenna in central position on prostomium, long and slender (1.1 mm long, Figs 2A, 4C); pair of lateral antennae placed on anterior prostomial margin, size similar to median antenna (1 mm long). Lips with lateral palps, shorter than lateral antennae (0.7 mm). Mouth ventral between peristomium and chaetiger 3. Caruncle oval (2.9 mm long, 1.7 mm wide), with an elevated central lobe with about 20 folds (Fig. 4C). Row of circular projection protruding between each pair of folds in middle of caruncle (Figs 2B, 4C). Lateral lobes flattened with pigmented base and folding edge with 19 and 22 folds (Fig. 4C). Branchiae from chaetiger 5 (Fig. 2I), present throughout body. Each branchia with main short stem, branching in several filaments of various thicknesses and lengths (Fig. 2E). First branchia with 11 branchial filaments, second branchia with about 20, middle one with about 40, posterior branchiae with 35–45 filaments up to the last chaetiger, where filaments are fewer. The large number of filaments causes a secondary ramification without a defined pattern. Parapodia biramous, notopodium with double cirri and neuropodium with single ventral cirrus. Notopodial cirri differing; accessory cirrus (= branchial cirrus) simple with similar length along body (1.0–1.2 mm); dorsal cirrus with short, thick cirrophore (0.5 mm) in first chaetigers, subsequent ones with long slender cirrophore (1 mm) and cirrostyle (1.5 mm, Fig. 2F). Ventral cirri similar along body, cirrophore short (0.2 mm) and cirrostyle long (1 mm), decreasing towards last chaetigers. Noto- and neurochaetae all asymmetrically furcated, slender (<0.03 mm), ratio of difference between short and long tines varies from three to four times (Fig. 2D). First chaetigers with some notochaetae with extra long tines, 10 to 30 times longer than short tines. Both neuro- and notochaetae include short and long types; shorter chaetae on exterior edge of chaetal lobe. Chaetae of first chaetigers with serrated margin. Some chaetae with an external “hard cover” that easily breaks up, giving the impression of being articulated (Fig. 2H). Anus dorsal, on chaetiger 23. Posterior end margin with pair of distal lobes (0.5 mm long, 0.5 mm wide in the widest part, Fig. 2G). Gametes: Gametes are located in the coelom. Oocytes are 40–57 μm in diameter (mean: 28.7±8.3 μm, n=20, one paratype female). Spermatozoids have a spherical head (~ 3 μm), ect-aquasperm type, aggregated in a mass (holotype). Variation: Material examined varied in total length from 1.0 to 2.1 cm, in width from 0.3 to 0.5 cm, chaetigers from 23 to 26, and varies in the following features. Prostomium: median antenna similar length to lateral ones (from 0.4 mm to 1 mm), palps shorter (0.3–0.7 mm). In some worms the pigmented strip on the prostomium continues to the buccal lips, around the palps, and even onto the ventral body with a dark region, although in holotype this pigmentation is faded. Caruncle fold number varies from 13 in smallest to 20; in all specimens number of folds between elevated lobe and laterals is very similar (±2). Pigmented circular projections in mid-caruncle faded in some preserved specimens. Number of branchial filaments is size-dependent, smallest specimens having only three to nine, largest specimens having up to 25 filaments in median region. Branchiae from chaetiger 5 in both juvenile and adults.

Greater Caribbean basin in shallow waters, related to coralline areas, particular associations are unknown.