Harmothoe extenuata ( Grube, 1840 )

Barnich, Ruth & Fiege, Dieter, 2009, Revision of the genus Harmothoe Kinberg, 1856 (Polychaeta: Polynoidae) in the Northeast Atlantic, Zootaxa 2104 (1), pp. 1-76 : 32-34

Harmothoe extenuata ( Grube, 1840)

( Figs. 3 ; 15A–J )

Polynoe extenuata Grube, 1840: 86 .

Lagisca extenuata: Marenzeller (1876) : 133, pl. 1 fig. 1; Saint-Joseph (1888): 180, pl. 8 figs. 52–54; Fauvel (1923): 76, fig. 28 [part, not Polynoe rarispina M. Sars, 1861 ]; Averincev (1977): 186, fig. 1; Hartmann-Schröder (1996): 57, fig. 17.

Harmothoe extenuata: Pettibone (1953) : 31 [part, not Polynoe rarispina M. Sars, 1861 ]; Pettibone (1954): 222 [part, not Polynoe rarispina M. Sars, 1861 ]; Chambers & Muir (1997): 98, fig. 23; Barnich & Fiege (2000): 1912 , fig. 12A–D; Barnich & Fiege (2003): 38, fig. 16A–D.

Harmothoe (Lagisca) extenuata: Pettibone (1963) : 41, fig. 8a–c [part, not Polynoe rarispina M. Sars, 1861 ].

Lepidonotus dumetosus Quatrefages, 1866: 259 .

Lepidonotus leachii Quatrefages, 1866: 258 .

Lagisca propinqua Malmgren, 1867: 133 , pl. 2 fig. 3.

Harmothoe sarniensis Lankester, 1867: 374 , pl. 51 figs. 10, 14–16, 24.

? Lepidonotus semisculptus Leach in Johnston, 1865: 116 [type (s) lost].

? Lagisca ehlersi pontica Czerniavsky, 1882:183 pl. 3 fig. 10A–C, a–l [type (s) lost].

Type material. Harmothoe extenuata : neotype, designated here, NHMW ZooEv 274 (selected out of 3 spms.), Italy, Bay of Naples, leg. 1882.

Lagisca propinqua : holotype, SMNH-Type-2398, Sweden, Bohuslän Koster , 58°57'N 11°5'E, leg. A.V. Ljungman.

Lepidonotus dumetosus : 3 syntypes, MNHN Poly type 89 & 90, France, St. Vaast (Normandy), leg. M. de Quatrefages.

Lepidonotus leachii : 2 syntypes, MNHN Poly type 103, France, St. Vaast (Normandy), leg. M. de Quatrefages , 1 syntype, MNHN Poly type 104, France, Granville (Normandy), leg. Audouin et Milne- Edwards.

Additional material. NE Atlantic : 1 spm., SMF 15271, Norway, 1884, leg. F.C. Noll. 1 spm., SMF 15274, Georg Berna-Expedition 1861, N Norway, Molde Fjord. 1 spm ., SMF 17281, N Norway, Tromsø area , Sommarøy, 69°38’N 18°02’E, 04 July 2002, lower shore, below stones, leg. & ded. C. d’Udekem d’Acoz. 1 spm ., SMF 13191, France, Roscoff , 18 March 2003, between Laminaria rhizomes, leg. C. Bleidorn. 1 spm., SMF 13199, France, Roscoff , near Île Verte, 20 March 2003, at low tide, below stone in Laminaria and seagrass zone, leg. R. Barnich & D. Fiege. 1 spm., SMF 17282, France, Beg-ar-Fry , near Plougasnou, 6 August 2005, leg. T. Wehe. 1 spm., SMF 17283, France, Île Callot , near Carantec, August 2005, leg. T. Wehe. 4 spms., SMF 12426, France, Presqu'île de Quibéron , Pointe du Congruel, intertidal, under stones, 08 April 1997, leg. C. d’Udekem d’Acoz. 14 spms., SMF 12425, France, Presqu'île de Quibéron , Pointe du Congruel, intertidal, under stones, 08 April 1997, leg. C. d’Udekem d’Acoz. 2 spms., SMF 13293, France, Piriac-surmer (Britany), intertidal, 06 April 1997, leg. C. d’Udekem d’Acoz. 1 spm., SMF 15581 (juv.), France, Piriacsur-mer (Britany), intertidal, 06 April 1997, leg. C. d’Udekem d’Acoz. 1 spm., SMF 13291, France, Golfe de Gascogne , NW Noirmoutier, NW Port du Morin, intertidal, 10 April 1997, leg. C. d’Udekem d’Acoz.

Diagnosis. Anterior pair of eyes dorsolateral at widest part of prostomium. Elytral margin with short, scattered papillae; surface covered by conical microtubercles, with a row of rounded, drop-shaped and often darkly pigmented macrotubercles near posterior margin.

Description (based on neotype of H. extenuata ).

Body with 43 segments. At anterior end ( Fig. 15A ), prostomium bilobed, with distinct cephalic peaks; ceratophore of median antenna in anterior notch, lateral antennae inserted ventrally, styles of antennae papillate, abruptly tapering subdistally 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, abruptly tapering subdistally to filiform tip. Second segment with first pair of elytra, biramous parapodia, and long buccal cirri. Following segments with tapering, short, sparsely 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 eleven segments cirrigerous; elytral margin and adjacent surface with short, scattered papillae; surface covered by conical microtubercles; macrotubercles drop-shaped, often with brownish pigment (in ethanol), in a row near posterior margin ( Fig. 15B,C ). Cirrigerous segments with distinct dorsal tubercles; dorsal cirri with cylindrical cirrophore, style papillate, abruptly tapering subdistally 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. 15D ). Notochaetae stouter than neurochaetae, with distinct rows of spines and blunt tip ( Fig. 15E,F ); neurochaetae with distinct rows of spines, mostly bidentate with distinct secondary tooth, some upper and lower unidentate ( Fig. 15G–J ).

Measurements. Neotype of H. extenuata (cs), NHMW ZooEv 274 ( Fig. 15A–J ): L 32 mm, W 5 mm for 43 segments. Holotype of L. propinqua (af), SMNH-Type-2398: L 16 mm, W 6 mm for 28 segments.

Remarks. Fauvel (1923) synonymised Lagisca propinqua Malmgren, 1867 and Polynoe rarispina M. Sars, 1861 with Lagisca extenuata ( Grube, 1840) ; this opinion was followed by Pettibone (1953), who consequently considered Lagisca Malmgren, 1866 to be a junior synonym of Harmothoe Kinberg, 1856 , and was adopted in our papers (see Barnich & Fiege 2000 and 2006). After having checked the available types and some more additional material of the respective species, we confirm that L. propinqua is a junior synonym of H. extenuata , since we could not find any relevant differences. Polynoe rarispina , however, is a valid Harmothoe species which can be easily recognised due to its elytra with prominent stick-shaped macrotubercles, while H. extenuata has much smaller drop-shaped macrotubercles.

We looked for the holotype of Polynoe extenuata in the collections of the Museum of Natural History Wroclaw ( Poland) and the Museum für Naturkunde Berlin ( Germany), where most of Grube’s types are deposited, and also in other German museums. As the type specimen was not found, we consider it now definitely lost. Grube’s rather short description of the species added to the confusion in the literature, especially regarding its possible junior synonyms. In the course of this revision it became clear, that there is a strong need for a neotype of this species, in order to allow correct distinction of H. extenuata , not only from species like L. propinqua or L. rarispina , but also from a number of other species, as shown in the identification key given here. The selected neotype is a specimen in perfect condition with numerous elytra originating from the Bay of Naples, the type locality indicated by Grube (1840: p. 2).

Distribution. Northeast Atlantic, Skagerrak, Kattegat, Öresund, North Sea, and Mediterranean Sea. Records outside this area are doubtful due to confusion with other species.

Habitat. On various substrates, in 0 to 400 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 15. Harmothoe extenuata (neotype, NHMW ZooEv 274). (A) anterior end; styles of left and right dorsal and left ventral tentacular cirri missing; style of right dorsal cirrus regenerating; (B) second right elytron from segment 4; (C) detail of posterior margin of same; (D) left cirrigerous parapodium from segment 16, posterior view, style of dorsal cirrus missing; (E) distal part of long notochaeta; (F) tip of same; (G) distal part of middle neurochaeta; (H) tip of same; (I) tip of uppermost neurochaeta; (J) tip of lower neurochaeta. (Scales: A, B = 1 mm; C, E, G = 100 µm; D = 500 µm; F, H–J = 50 µm).