Leucia nivea M. Sars 1863

• Main Authors: Barnich, Ruth, Fiege, Dieter
• Format: Text
• Language: unknown
• Published: Zenodo 2010
• Subjects: Biodiversity; Taxonomy; Animalia; Annelida; Polychaeta; Phyllodocida; Polynoidae; Leucia; Leucia nivea; Norway; Nivea; McIntosh; Paa; Noto; Sleppen; Northeast Atlantic
• Online Access: https://dx.doi.org/10.5281/zenodo.6210061; https://zenodo.org/record/6210061

Leucia nivea (M. Sars, 1863) (Fig. 4 A–I) Polynoe nivea M. Sars, 1863: 291. Leucia nivea : Chambers (1989): 145, fig. 1; Loshamn (1980, unpubl. thesis): 97 fig. 48. Polynoe zonata Langerhans, 1880: 275. Harmothoe echinopustulata Fauvel, 1913: 19; Fauvel (1914): 58, pl. 4 figs. 7–10, 21 – 26. (for extended synonymy see Chambers 1989) Type material. Polynoe nivea : holotype, ZMO C 3156 a (fragmented; elytra all missing) and ZMO C 3156 b (slide with parapodium), NE Atlantic, Norway, Trondheimsfjord, Beian, 30–40 fathoms. Additional material. 3 spms. (cs), VM 23936, NE Atlantic, Norway, Trondheimsfjord, Nr. 45. 1 spm. (cs), VM 23937, NE Atlantic, Norway, Røberg, 10 May 1950, 130– 250 m, coral ground, leg. Sievertsen. 1 spm. (cs), VM 23938, NE Atlantic, Norway, Fenrissund, 29 June 1971, 30– 50 m, leg. Trondheim Biological Station. 1 spm. (af), VM 23939, NE Atlantic, Norway, Budgrunnen, 4 July 1931, 40 – 60 m, moraine, MS "Gunnerus", leg. Trondheim Biological Station. 1 spm. (cs), VM 23940, NE Atlantic, Norway, Sleppen, Svaerholt, 22 July 1937, 200– 220 m. Diagnosis. Elytral margin without papillae; anterior half of elytra covered by conical to spine-shaped microtubercles, posterior half by semi-globose, spiny macrotubercles. Description (based on complete specimen, VM 23936; holotype incomplete). Body with 41 segments. At anterior end (Fig. 4 A), prostomium bilobed, with distinct cephalic peaks; ceratophore of median antenna in anterior notch, style papillate (tip broken); lateral antennae inserted ventrally, styles missing; 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 few 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 short, tapering, papillate ventral cirri. Sixteen pairs of elytra, covering dorsum, on segments 2, 4, 5, 7, then on every second segment to 23, 26, 29, 32, 35; last six segments cirrigerous; elytral margin without papillae, anterior half of elytra covered by conical to spine-shaped microtubercles, posterior half covered by semi-globose, spiny macrotubercles (Fig. 4 B,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 digitiform supra-acicular process; neuropodial postchaetal lobe shorter than prechaetal lobe, rounded; tips of noto- and neuroacicula penetrating epidermis (Fig. 4 D). Notochaetae stouter than neurochaetae, with distinct rows of spines and blunt tip (Fig. 4 E,F); neurochaetae with distinct rows of spines, tips mainly bidentate with fragile secondary tooth (often abraded), some lower neurochaetae unidentate (Fig. 1 G–I). Measurements. Specimens from Trondheimfjord (VM 23936): cs, L 25 mm, W 6 mm for 41 segments (Fig. 4 A–I); cs in two fragments, regenerating end, L 25 mm, W 8 mm for 43 segments; af with few posterior segments missing, L 25 mm, W 8 mm for 42 segments. Remarks. Although the holotype of L. nivea is fragmented with some middle segments and all elytra missing, the original description by M. Sars (1863) is sufficient to allow the correct identification of the species. Leucia nivea was figured by Fauvel (1914) and Chambers (1989), but unfortunately the correct shape of the macrotubercles remained rather difficult to evaluate. Having now studied more material we present here a redescription based on a complete specimen. Apart from Leucia nivea , there is currently only one more species known in the genus, L. violacea (Storm, 1879), which has been redescribed by Fiege & Barnich (2009) and is characterised by its rather indistinct, scattered, conical to mamilliform macrotubercles, while in L. nivea macrotubercles are distinct, semi-globose, spiny mounds. In the same paper however, characters given for L. nivea have been confused with those of Acanthicolepis zibrowii n. sp. described below. Both species have spiny macrotubercles, but they differ clearly in their shape: in A. zibrowii n. sp. macrotubercles are cylindrical to club-shaped (Fig. 5 C), while in L. nivea they are comparatively low and semi-globose (Fig. 4 C). Besides this, they show the typical number of elytra of their respective genus: 16 pairs for Leucia and 18 pairs for Acanthicolepis (see also remarks related to A. zibrowii n. sp. below). Distribution and habitat. Northeast Atlantic from Norway down to Madeira; on various substrates, including cold-water corals, from 8 to 300 m (see Chambers 1989). : Published as part of Barnich, Ruth & Fiege, Dieter, 2010, On the distinction of Harmothoe globifera (G. O. Sars, 1873) and some other easily confused polynoids in the NE Atlantic, with the description of a new species of Acanthicolepis Norman in McIntosh, 1900 (Polychaeta, Polynoidae), pp. 1-18 in Zootaxa 2525 on pages 11-13, DOI: 10.5281/zenodo.196399 : {"references": ["Sars, M. (1863) Geologiske og zoologiske Iagttagelser, anstillede paa en Reise i en Deel af Trondhjems Stift i Sommeren 1862. II. Zoologiske Notitser fra Christiansund og Bejan. Nyt Magazin for Naturvidenskaberne, 12 (3), 273 - 340.", "Chambers, S. J. (1989) Leucia nivea, A polynoid (Polychaeta) new to the British Isles. Irish Natural History Journal, 23 (4), 145 - 147.", "Loshamn, A. A. (1980) En systematisk og dyregeografisk Undersokelse over Skjellrygg-Gruppen (Familie Aphroditidae sensu Fauvel 1923). Dissertation. Zoologisk Institutt, Universitete i Oslo, 184 pp. [unpublished].", "Langerhans, P. (1880) Die Wurmfauna Madeiras, II. Zeitschrift fur wissenschaftliche Zoologie, 33, 271 - 316.", "Fauvel, P. (1913) Quatrieme note preliminaire sur les polychetes provenant des campagnes de l' \" Hirondelle \" et de la \" Princesse-Alice \", ou deposees dans le Musee Oceanographique de Monaco. Bulletin de l'Institut Oceanographique, Monaco, 270, 1 - 80.", "Fauvel, P. (1914) Annelides Polychetes non pelagiques provenant des Campagnes de l' \" Hirondelle \" et de la \" Princesse- Alice \" (1885 - 1910). Resultats des campagnes scientifiques accomplies sur son yacht par Albert I er Prince Souverain de Monaco, 46, 1 - 432.", "Storm, V. (1879) Bidrag til Kundskab om Throndhjemsfjordens Fauna. Det Kongelige Norske Videnskabers Selskabs Skrifter, 1878, 9 - 36."]}