Euchone pallida Ehlers 1908

• Main Authors: Licciano, Margherita, Giangrande, Adriana, Gambi, Maria Cristina
• Format: Other/Unknown Material
• Language: unknown
• Published: 2009
• Subjects: Biodiversity; Taxonomy; Animalia; Annelida; Polychaeta; Sabellida; Sabellidae; Euchone; Euchone pallida; Deception Island; Livingstone; Fang; Livingstone Island
• Online Access: https://zenodo.org/record/6213861; https://doi.org/10.5281/zenodo.6213861

Euchone pallida Ehlers, 1908 Figure 1 Material examined. 6 specimens (2 Ƥ, 23, 2 broken and undifferentiated) collected in St. DR 1 (77 m depth) off Livingstone Island (6 th January 2006); 14 specimens (7 Ƥ and 73) collected at St. DR 3 (100 m depth) off Deception Island. M.C. Gambi legit. 1 specimen is deposited at the PCZN (232), 13 specimens at the SZN - POLY (13). Revised description. Medium sized sabellid with eight thoracic and 34 abdominal chaetigers, of which 14-15 form the anal depression (Fig. 1 D). Branchial lobes each with 20 radioles with small filiform tip (Fig. 1 C) and palmate membrane covering the ¾ of the length. Dorsal lips rounded, extending from inner, dorsal margin of branchial lobes, and terminating just dorsal to mouth, with poorly developed radiolar appendage. First pinnula of dorsalmost radioles separated from other pinnules and highly developed and ticker than the others, here defined as dorsal “pinnular appendages” (Fig. 1 E). Ventral lips pointed, up to twelve short ventral radiolar appendages (Fig. 1 E). Collar entire with edge terminating at same height all around and covering base of branchial crown, with thick pouches extending dorsally towards second chaetiger (Fig. 1 A). Methyl green staining pattern shows a homogeneous dark coloration of thorax and abdomen with distinct intra-segmental furrow, except for presence of thin glandular ridge on chaetiger two (Fig. 1 B). Inferior anterior thoracic chaetae narrowly hooded (Fig. 1 F). Thoracic uncini with long handle and series of small teeth of similar size above main fang (Fig. 1 G). Abdominal uncini from pre-pygidial depression and depression chaetigers similar (Fig. 1 H, I), with main fang surmounted by few rows of small teeth, breast rectangular, not extending beyond distal end of proximal tooth, handles absent. Variation within a torus absent. Remarks. Chaetiger and radiolar number, shape of the collar and posterior abdominal depression all correspond well to the original description by Krøyer (1856), as well as that of Banse ...