Harmothoe fernandi, Barnich & Fiege, 2009

Barnich, Ruth & Fiege, Dieter, 2009, Revision of the genus Harmothoe Kinberg, 1856 (Polychaeta: Polynoidae) in the Northeast Atlantic, Zootaxa 2104 (1), pp. 1-76 : 34-35

Harmothoe fernandi n. sp.

( Figs. 5 ; 16A–I )

Evarne johnstoni: McIntosh (1900) : 358, pl. 32 fig. 19, pl. 39 figs. 23–28 [part, not E. johnstoni McIntosh, 1876 , indeterminable].

Type material. H. fernandi : holotype (cs with everted pharynx), SMF 17294, "Johan Ruud" St. 725, 69°35.34’N, 17°54.80’E, N Norway, Malangen Hekkingen , 27 September 2002, epibenthic sledge, 411 m, leg. & ded. C. d’Udekem d’Acoz .

Paratype (af), SMF 17295, "Johan Ruud" St. 725, 69°35.34’N, 17°54.80’E, N Norway, Malangen Hekkingen , 27 September 2002, epibenthic sledge, 411 m, leg. & ded. C. d’Udekem d’Acoz .

Additional material. NE Atlantic: 1 spm. (af, juv., poor condition), SMF 17296, Alta resip. 2005, St. S 4-2, 9 November 2005, 69°57.546’ N, 23°12.747’ E, 26 m, ded. A. Sikorski. 1 spm. (af, juv.), SMF 17297, Alta resip. 2005, St. S 5-1, 9 November 2005, 69°57.990’ N, 23°14.167’ E, 28 m, ded. A. Sikorski .

Diagnosis. Anterior pair of eyes dorsolateral at widest part of prostomium. Elytral margin and adjacent surface with long papillae; surface with conical microtubercles getting larger towards posterior margin. Neurochaetae very slender and, except for some uppermost neurochaetae, with reduced rows of spines.

Description (based on holotype).

Body with 33 segments. At anterior end ( Fig. 16A ), prostomium bilobed, with distinct cephalic peaks; ceratophore of median antenna in anterior notch, lateral antennae inserted ventrally, styles of antennae papillate, tapering; 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 four notochaetae and a dorsal and ventral tentacular cirrus, styles of cirri papillate, tapering. Second segment with first pair of elytra, biramous parapodia, and long buccal cirri. Following segments with tapering, short, papillate 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 segment cirrigerous; outer lateral and posterior elytral margin and adjacent surface with long papillae; surface with conical microtubercles getting larger towards posterior margin. ( Fig. 16B,C ). Cirrigerous segments with distinct dorsal tubercles; dorsal cirri with cylindrical cirrophore, style papillate, tapering.

Parapodia biramous; notopodia with elongate acicular lobe; neuropodia with elongate prechaetal acicular lobe with long, digitiform supra-acicular process; neuropodial postchaetal lobe shorter than prechaetal lobe, rounded; tips of noto- and neuroacicula penetrating epidermis ( Fig. 16D ). Notochaetae much stouter than neurochaetae, with distinct rows of spines and blunt tip ( Fig. 16E ); neurochaetae very slender, except for some uppermost neurochaetae, with reduced rows of spines; tip of upper and middle neurochaetae bidentate with short secondary tooth, lower unidentate. ( Fig. 16F–I ).

Measurements. Holotype (cs), SMF 17294 ( Fig. 16A–I ): L 13 mm, W 3 mm for 33 segments. Paratype (af), SMF 17295: L 8 mm, W 4 mm for 18 segments. Additional material: 1 spm. (af, juv.), SMF 17296: L 1.5 mm, W 0.7 mm for 12 segments. 1 spm. (af, juv.), SMF 17297: L 4 mm, W 1.5 mm for 20 segments.

Remarks. Harmothoe fernandi n. sp. and H. abyssicola Bidenkap, 1894 have similar slender neurochaetae with reduced rows of spines, but H. abyssicola differs due to its elytra with scattered marginal papillae and conical microtubercles, and few, conical to globose, macrotubercles near the posterior margin.

Slender neurochaetae with reduced rows of spines were also described for Evarne johnstoni McIntosh, 1876 and Polynoe borealis Théel, 1879 , both indeterminable, since their type specimens lack elytra and the respective descriptions are insufficient (see Table 2.). Thus, specimens occurring in the Northeast Atlantic and showing slender neurochaetae with reduced rows of spines, but differing from H. abyssicola by their elytra are referred here to H. fernandi n. sp.

Part of the additional specimens of Evarne johnstoni McIntosh, 1876 described and figured in McIntosh (1900) show elytral and neurochaetal characters similar to those of the new species. Unfortunately, these specimens from Norway present in the collection of the British Museum ( BMNH 1921.5.1.482) were not only indeterminable (all are anterior fragments lacking elytra), but consist of a mixture of at least two species, three specimens showing neurochaetae with reduced rows of spines as mentioned above, and one specimen showing neurochaetae with distinct rows of spines as in many other Harmothoe species .

Harmothoe fernandi n. sp. may be confused with H. viridis Loshamn, 1981 and H. oculinarum ( Storm, 1879) . In H. viridis elytral microtubercles are less prominent, marginal papillae are shorter and less numerous, and in H. oculinarum microtubercles are confined to a patch near the anterior margin. Finally neurochaetae of both species are only slightly more slender than the notochaetae and show distinct rows of spines.

Distribution. Northeast Atlantic, northern Norway.

Habitat. Unknown, in 26 to 411 m.

Etymology. The species is named after Fernand Barnich for his continuous support and interest in our work.

Figures

FIGURE 5. Identification characters of Harmothoe fernandi n. sp., H. oculinarum, H. gilchristi, H. aequespina, H. glabra, and H. viridis.

FIGURE 16. Harmothoe fernandi n. sp. (holotype, SMF 17294). (A) anterior end; styles of median antenna and dorsal tentacular cirri missing; everted pharynx not figured; (B) third right elytron from segment 5; (C) detail of posterior margin of same; (D) left cirrigerous parapodium from segment 6, posterior view, style of dorsal cirrus missing; (E) distal part of long notochaeta; (F) distal part of middle neurochaeta; (G) tip of same; (H) tip of upper neurochaeta; (I) tip of lower neurochaeta. (Scales: A, B = 1 mm; C, D = 250 µm; E, F = 100 µm; G–I = 50 µm).