Phalacrostemma perkinsi Kirtley 1994

• Main Author: Chávez-López, Yessica
• Format: Other/Unknown Material
• Language: unknown
• Published: 2022
• Subjects: Biodiversity; Taxonomy; Animalia; Annelida; Polychaeta; Sabellida; Sabellariidae; Phalacrostemma; Phalacrostemma perkinsi; North Atlantic
• Online Access: https://zenodo.org/record/6885912; https://doi.org/10.5281/zenodo.6885912

Phalacrostemma perkinsi Kirtley, 1994 Figs 13–15 Phalacrostemma perkinsi Kirtley, 1994: 163, fig. 9.8a–c. Type locality: The Bahamas, 1362–1364 m depth. Material examined NORTH ATLANTIC – Southeastern Bahamas • 1 spec.; RV Columbus Iselin, stn 47: 23°43′ N, 77°09′ W; depth 3000 m; 24 Feb. 1973; UMML-22.1191 • 1 spec. (using mid operculum for SEM); same collection data as for preceding; UMML-22.1192 • 1 spec.; RV Columbus Iselin, stn 250; 23°52′ N, 76°56′ W; depth 1305 m; 31 Oct. 1974; UMML-22.1193 • 1 spec.; same collection data as for preceding; ECOSUR-P3239. Description BODY. Incomplete specimen (UMML-22.1191), 13 mm long, 3 mm wide, six abdominal segments (Fig. 13A–F). OPERCULUM. Opercular disc truncate (Fig. 13A–B). Opercular crown with some broken or missing paleae. Outer paleae arranged spirally, 22 paleae on right lobe, 14 paleae on left. Inner paleae arranged diagonally, two paleae on each lobe. Outer paleae amber, cylindrical, 3–4 mm long (Figs 14A–E, 15A– D). Proximal region with compacts thecae, margins non-expanded (Fig. 14B, D). Thecae of middle region with margins non-expanded (Fig. 15E) to slightly irregularly expanded (Figs 14C, 15F). Thecae of mid-distal region elongate with margins irregularly expanded (Fig. 15G); tips hirsute (Figs 14D, 15H). Inner paleae amber, cylindrical, with thecae inconspicuous; tips lanceolate (Figs 14E, 15I). Opercular stalk brown. Opercular papillae in two rows, each row with 11–13 opercular papillae on each lobe (Fig. 13B). Papillae conical, tapered, 2–4 times as long as wide (Figs 13B, 15B). First papilla appears in dorsal region of opercular peduncle, at level of nuchal hooks. Six pairs of amber nuchal hooks, compressed, tips sharp falcate, with limbation. Limbation not reaching tip curvature, 1.5 times as long as tip (Figs 14G, 15C). Palps robust, tapered, three times as long as wide (Fig. 13D). Pair of broad buccal flaps (Fig. 13D). Tentacular filaments absent. Median organ conical, brownish, without eyespots. Building organ U-shaped, brown. THORAX. First ...