Harmothoe fragilis Moore, 1910

Barnich, Ruth & Fiege, Dieter, 2009, Revision of the genus Harmothoe Kinberg, 1856 (Polychaeta: Polynoidae) in the Northeast Atlantic, Zootaxa 2104 (1), pp. 1-76 : 37-39

Harmothoe fragilis Moore, 1910

( Figs. 3 , 17A–K )

Harmothoe (Evarne) fragilis Moore, 1910: 353 , pl. 29 figs. 29, 30, pl. 30 figs. 31, 32.

Harmothoe fragilis: Hartmann-Schröder (1996) : 44; Chambers & Muir (1997): 100, fig. 24; Barnich & Fiege (2000): 1911 , fig. 11A–D; Barnich & Fiege (2003): 41, fig. 17A–D.

Evarne impar: Malmgren (1866) : 71, pl. 9 fig. 7 [not Johnston, 1839].

Type material. Harmothoe (Evarne) fragilis : holotype, USNM 17148 , RV "Albatross" St. 4413, off Santa Catalina Island (California), 11 April 1904, 152 fms .

Additional material. NE Atlantic: 1 spm., SMF 17324, "Johan Ruud" St. 734, 69°52.04’N, 18°52.82’E, N Norway, Kvalsund i Kårvik, 7 October 2002, epibenthic sledge, 60 m, leg. & ded. C. d’Udekem d’Acoz. 1 spm. (af), SMF 17310, "Johan Ruud" St. 819, 69°32.66’N, 18°06.69’E, N Norway, Malangen Buvika, 29 October 2002, epibenthic sledge, 39 m, leg. & ded. C. d’Udekem d’Acoz. 2 spms., SMF 17308–17309, "Johan Ruud" St. 737, 69°49.90’N, 17°53.25’E, N Norway, S of Malangsgrunnen, 08 October 2002, epibenthic sledge, 139 m, leg. & ded. C. d’Udekem d’Acoz. 3 spms., SMF 17312, "Johan Ruud" St. 297, 68°22’N 15°47’E, N Norway, Kanstadfjord Katnesholmen, 06 May 2004, 132 m, leg. & ded. C. d’Udekem d’Acoz. 1 spm. (af, mf), SMF 17311, "Johan Ruud" St. 289, 70°13.87’N 22°31.93’E, N Norway, Stjernsund, outer Lokkarfjord, 12 April 2005, dive, 20 m, leg. & ded. C. d’Udekem d’Acoz. 3 spms., SMF 17314–17316, "Johan Ruud" St. 298, 70°58.73’N 25°17.78’E, N Norway, Magerøysundet Stikkelsvågnaeringen, 13 April 2005, dive, 20 m, leg. & ded. C. d’Udekem d’Acoz. 3 spms., SMF 17317–17319, "Johan Ruud" St. 299, 70°59.26’N 25°19.99’E, N Norway, Magerøysundet Stikkelsvågnaeringen, 13 April 2005, dive, 20 m, leg. & ded. C. d’Udekem d’Acoz. 1 spm., SMF 17320, "Johan Ruud" St. 300, 71°00.28’N 25°12.49’E, N Norway, Vannfjordryggen, 13 April 2005, dive, 20 m, leg. & ded. C. d’Udekem d’Acoz. 2 spms., SMF 17321–17322, "Johan Ruud" St. 301, 71°00.29’N 25°21.59’E, N Norway, Vannfjorden, 13 April 2005, dive, 20 m, leg. & ded. C. d’Udekem d’Acoz. 1 spm., SMF 17323, "Johan Ruud" St. 309, 70°59.32’N 25°20.50’E, N Norway, Stikkelsvågnaeringen, 14 April 2005, dive, 20 m, leg. & ded. C. d’Udekem d’Acoz. 1 spm., SMF 17313, "Johan Ruud" St. 465, 69°34.92’N 18°55.92’E, N Norway, Balsfjord Berg, 08 May 2006, triangular dredge, 29 m, leg. & ded. C. d’Udekem d’Acoz .

(For further material see Barnich & Fiege 2000 and 2003).

Diagnosis. Anterior pair of eyes dorsolateral at widest part of prostomium. Elytral margin with fringing papillae; surface covered by conical microtubercles and few scattered papillae, with a row of rounded, soft and flattened macrotubercles near posterior margin, giving margin a scallop-shaped appearence.

Description (based on additional specimen SMF 17309, since holotype in rather poor condition).

Body with 39 segments. At anterior end ( Fig. 17A ), prostomium bilobed, with distinct cephalic peaks; ceratophore of median antenna in anterior notch, lateral antennae inserted ventrally, styles of antennae papillate, tapering to filiform tip; anterior pair of eyes situated dorsolaterally at widest part of prostomium, posterior pair dorsally near hind margin of prostomium; palps papillate, tapering.

Tentaculophores inserted laterally to prostomium, each with two notochaetae and a dorsal and ventral tentacular cirrus, styles of cirri papillate, tapering to filiform tip. Second segment with first pair of elytra, biramous parapodia, and long buccal cirri. Following segments with tapering, short ventral cirri.

Fifteen pairs of elytra, covering dorsum, on segments 2, 4, 5, 7, then on every second segment to 23, 26, 29, 32; last seven segments cirrigerous; elytral margin with fringing papillae; surface covered by conical microtubercles and few scattered papillae, with a row of rounded, soft and flattened macrotubercles near posterior margin, giving margin a scallop-shaped appearence ( Fig. 17B,C ). Cirrigerous segments with distinct dorsal tubercles; dorsal cirri with cylindrical cirrophore, style papillate, tapering to filiform tip.

Parapodia biramous; notopodia with elongate acicular lobe; neuropodia with elongate prechaetal acicular lobe with digitiform supra-acicular process; neuropodial postchaetal lobe shorter than prechaetal lobe, rounded; tips of noto- and neuroacicula penetrating epidermis ( Fig. 17D ). Notochaetae stouter than neurochaetae, with distinct rows of spines and blunt tip ( Fig. 17E–G ); neurochaetae with distinct rows of spines, mostly bidentate with slender secondary tooth (often abraded), some lower unidentate ( Fig. 17H–K ).

Measurements. H. fragilis , holotype, USNM 17148: L 19 mm, W 6 mm for 38 segments. Specimen figured, SMF 17309 ( Fig. 17A–K ): L 20 mm, W 5 mm for 39 segments.

Distribution. Arctic, North Pacific, North Atlantic, Skagerrak, Kattegat, and western Mediterranean Sea. Habitat. On muddy and sandy substrata from 20 to 300 m.

Figures

FIGURE 3. Identification characters of Harmothoe impar, H. clavigera, H. rarispina, H. extenuata, H. fragilis, H. vesiculosa, H. abyssicola, and H. mariannae n. sp.

FIGURE 17. Harmothoe fragilis (additional specimen, SMF 17309). (A) anterior end; styles of tentacular cirri and left dorsal cirrus of segment 3 missing; (B) right elytron from segment 5; (C) detail of posterior margin of same; (D) right cirrigerous parapodium from segment 14, posterior view, style of dorsal cirrus missing; (E) long notochaeta; (F) tip of same; (G) short notochaeta; (H) middle neurochaeta; (I) tip of same; (J) tip of uppermost neurochaeta; (K) tip of lower neurochaeta. (Scale: A, B = 2 mm; C, E, G, H = 250 µm; D = 1 mm; F, I–K = 50 µm).