Chaetozone setosa Malmgren 1867

• Main Author: Blake, James A.
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2015
• Subjects: Biodiversity; Taxonomy; Animalia; Annelida; Polychaeta; Terebellida; Cirratulidae; Chaetozone; Chaetozone setosa; Arctic; Isfjord*; Spitsbergen
• Online Access: https://doi.org/10.5281/zenodo.5664928; http://treatment.plazi.org/id/9A3E87FEEB62FFD9D2F7FB23FC38F9D0

Chaetozone setosa Malmgren, 1867 Figures 1‒2; Table 1 Malmgren 1867: 96, Pl. 14, Fig. 84; Petersen 1999: 111; Chambers 2000: 589‒591, Fig. 1. Material examined. Norwegian Arctic, Spitsbergen, Isfjord, 30 fathoms (55 m), coll. 0 6 June 1864, A.J. Malmgren syntype lot SMNH 1493: Lectotype, female, SMNH 1493-03 examined by Dr. Mary E. Petersen and designated in print (Petersen 1999); 38 Paralectotypes from SMNH 1493: 1493-01, 1493-02, 1493-04‒36; data on these collections provided with illustrations, sketches, and descriptive data from preliminary manuscript by Dr Petersen, dated 0 3 April 2001; eight prepared slides of parapodia and illustrations from paralectotype 1493-33 also provided by Dr. Petersen; additional study of prepared slides including preparation of photomicrographs, by J.A. Blake, September 2014. Description. A moderately sized species, lectotype a complete ovigerous female, 20.2 mm long, 1.7 mm wide for 90 setigerous segments; complete paralectotypes up to 28 mm long, 2 mm wide for 94 setigerous segments (Table 1). Body of most preserved specimens curled into a C-shape, but not strongly coiled. Body thickened in middle, narrowing anteriorly and posteriorly. Anterior setigers short, wide, becoming up to 2 times longer in middle body segments, but always narrower than wide except for some segments on ovigerous specimens. Dorsal groove weakly developed, narrow, often limited to anterior setigers; ventral groove well-developed, visible along most of body, absent in far posterior cinctured segments. Color in alcohol brown or grey; no distinct pigmentation. Prostomium conical, narrow, bluntly pointed anteriorly (Fig. 1 A); eyes absent; nuchal organs narrow diagonal slits, not pigmented. Peristomium with two large, distinct rings best visible laterally, overlain dorsally by swollen peristomial crest with peristomial annulations weakly developed or not apparent on crest (Fig. 1 A), crest overlapping prostomium anteriorly, narrowing posteriorly, extending to near anterior margin of achaetous segment 1. ...