Species of Nereididae from the Capbreton Canyon (Bay of Biscay, Northeast Atlantic)

Species of Nereididae from the Capbreton Canyon (Bay of Biscay, Northeast Atlantic)

BULLETIN OF MARINE SCIENCE, 67(1): 25–37, 2000 SPECIES OF NEREIDIDAE FROM THE CAPBRETON CANYON (BAY OF BISCAY, NORTHEAST ATLANTIC) Jorge Núñez, Florencio Aguirrezabalaga and Argiloa Ceberio ABSTRACT Five species of Nereididae collected from the Capbreton Canyon, southeastern part of the Bay of Biscay, in deep waters (480–1040 m) are described. Three species are new to the Atlantic: Nicon sinica Wu and Sun, 1979, Ceratocephale cf. pacifica (Hartman, 1960) and C. cf. andaman Hylleberg and Nateewathana, 1988; and one, Ceratocephale loveni Malmgren, 1867 is new record for the Iberian fauna. The distributional range for Eunereis longissima (Johnston, 1840) in the Iberian region is extended. The Capbreton Canyon begins at 250 m from the coastline near Capbreton and stretches from the east to the west along 135 nautical mi. This canyon divides the continental shelf of the Bay of Biscay into two zones. The benthic macrofauna of this canyon was studied by Le Danois (1948), who distinguished two levels: the upper one between 70 and 500 m depth was dominated by scleractinian and alcionarian facies, whereas the lower one be- tween 500 and 1000 m was characterized by the presence of hexactinelids and echino- derms. Four oceanographic cruises were carried out on board the RV CÔTE D’AQUITAINE from 1987–1990, in which studies of macrofauna communities were included. The first results relating to polychaetous annelids were published by Rallo (1988), Rallo et al. (1993), García-Arberas and Rallo (1994), and San Martín et al. (1996). The objective of this work was to extend the knowledge of the polychaete fauna, particularly the deep-sea benthic Nereididae from the Bay of Biscay. MATERIAL AND METHODS The specimens belonging to the Nereididae family were collected at seven of the stations dredged during the Capbreton 1988 and 1990 cruises (Fig. 1, Table 1). Samples were made with three types of gear: a Sanders-Hessler epibenthic dredge with a mesh size of 0.5 mm, a Reineck box-corer (sample sieved with a mesh of 0.5 mm), and a Marinovitch trawl. The samples were fixed in a 10% formaldehyde-seawater solution and preserved in a 70% alcohol solution. For identification, parapo- dia from the majority of the specimens were removed and permanent slide mounts in a glycerin gel were made. The drawings were made to scale, with the aid of a drawing tube coupled to a LEICA DMLB optic microscope equipped with interference contrast optics (Nomarski). The specimens were deposited at the Museo Nacional de Ciencias Naturales de Madrid (MNCNM), Spain. 25 26 BULLETIN OF MARINE SCIENCE, VOL. 67, NO. 1, 2000 Figure 1. Map of Capbreton (Bay of Biscay) showing sampled stations. SYSTEMATICS Ceratocephale loveni Malmgren, 1867 (Fig. 2A–J) Ceratocephale loveni Malmgren, 1867: 61, pl. 5, fig. 33.—Pettibone, 1963: 152, fig. 4a,b.— Hartmann-Schröder, 1971: 191.—1974: 200, figs. 19–22.—Amoureux, 1982: 42, fig. 6.—Cham- bers and Garwood, 1992: 26, figs. 40,12,24,51.—Hilbig, 1997: 297, fig. 12.2. Ceratocephale borealis Wesenberg-Lund, 1950: 18, pl. 5, figs. 19–21; pl. 6, figs. 23–26. Material Examined.—Five spec., sta. DI-19; one spec., sta. CM-22. Description.—Six incomplete specimens without posterior end. Largest specimen with 30 setigers, 6.5 mm long and 0.4 mm wide without parapodia and setae. Preserved mate- rial brown in color with golden setae and dark brown aciculae. Anterior 11 setigers in- flated, rest of body narrow with setigers similar in width. Anterior setigers (3–11) with numerous golden setae, following setigers with fewer setae and pale golden color. NÚÑEZ ET AL.: NEREIDIDAE FROM CAPBRETON CANYON, BAY OF BISCAY 27 Table 1. Sampling data in the Capbreton Canyon during the cruise CAPBRETON 1898 −90. DI = Sanders-Hessler epibenthic dredge, CM = Marinovitch trawl, KR = Reineck box-corer. Station Position at the beginning and the Depth (m) at the Doate N end of the tow on the sea-floor beginning and the end individuals DI 13 43° 38.36'N−20° 18.03'W 1804 017/06/8 43° 38.08'N−27° 18.14'W 100 DI 19 43° 37.48'N−12° 52.52'W 985 057/07/8 43° 37.46'N−18° 52.66'W 96 DI 21 43° 37.72'N−10° 41.83'W 588 017/07/8 43° 37.43'N−10° 41.99'W 48 DI 26 43° 42.89'N−24° 18.71'W 988 017/08/8 43° 43.25'N−29° 18.80'W 102 CM 22 43° 37.79'N−14° 42.91'W 682 017/07/8 43° 37.50'N−12° 43.09'W 65 CM 27 43° 43.19'N−24° 20.13'W 985 057/08/8 43° 44.54'N−27° 18.18'W 91 KR 24 43° 43.69'N−20° 18.03'W 906 017/07/9 Prostomium deeply incised, with pair of stout frontal antennae, as long as palps; biarticulated palps, with elongate palpostyles (Fig. 2A); eyes absent. Peristomium achaetous, short, similar in length to following segments. Four pairs of tentacular cirri similar in length, longest reaching back to setiger 3. Pharynx not everted, pair of light brown, serrated jaws visible after dissection. Parapodia of first two setigers uniramous, with triangular postsetal lobe and digitiform neuro-acicular papilla, ventral neuropodial ligule cirriform, shorter than postsetal lobe. Dorsal cirri filiform, slightly longer than inferior lobe, single ventral cirri shorter than lobe and ligule. Setae homogomph spinigers. Following parapodium biramous. Dorsal cirri on first 9 setigers with small cirrophores (Fig. 2B), parapodia from setigers 10–20 with cirrophore of dorsal cirri elongated, inflated, vascularized and ciliated (Fig. 2C). Posterior parapodia with dorsal cirri slender and very long, without elongated cirrophore. Ventral cirri bifid from setiger 3. Notopodia of setiger 7 with prominent triangular presetal ligule and short rounded postsetal lobe. Neuropodia with broad lobe and small conical neuroacicular papilla, conical presetal ligule, slightly longer, rounded postsetal lobe and blunt, triangular ventral ligule. Notopodia of setiger 10 shorter than that of setiger 7 and neuropodial lobes small. Posterior setiger (23) with parapodia smaller than those of more anterior one of the body, short notopodial lobe and elongated neuropodial lobes (Fig. 2D). Setae include homogomph and sesquigomph spinigers (Fig. 2E–F,H–J), with blade sligtlhy serrated, and 2–4 sesquigomph spinigers with strongly serrated blades (Fig. 1G). Falcigerous setae absent. Distribution.—North Atlantic: Greenland, Scandinavia, Ireland, Bay of Biscay, Nova Scotia to Virgini, Sea of Okhotsk. Pacific: Gulf of Alaska, Valparaiso, Cape Horn (50– 5000 m depth). 28 BULLETIN OF MARINE SCIENCE, VOL. 67, NO. 1, 2000 Figure 2. Ceratocephale loveni. A. anterior end, dorsal view, B. parapodium, setiger 7, C. parapodium, setiger 10, D. parapodium, posterior setiger, E. notoseta from setiger 3, F. neuroseta, shaft from setiger 3, upper bundle, G. neuroseta from setiger 3, lower bundle, H. notosetae, shafts from setiger 7, I. neuroseta from setiger 12, upper bundle, J. neuroseta, setiger 12, lower bundle. Scale: A = 0.4 mm; B–D = 237 µm; E–J = 29 µm. Ceratocephale cf. pacifica (Hartman, 1960) (Fig. 3A–I) Ceratocephale loveni pacifica Hartman, 1960: 94, pl. 8.—Hartman, 1968: 501. Ceratocephale pacifica.—Banse, 1977: 617, fig. 2a.—Hilbig, 1997: 299, fig. 12.2. Ceratocephale ?pacifica.—Hutchings and Reid, 1990: 82, fig. 7a–e, tables 7,9. Material Examined.—One spec., sta. KR 24. NÚÑEZ ET AL.: NEREIDIDAE FROM CAPBRETON CANYON, BAY OF BISCAY 29 Figure 3. Ceratocephale cf. pacifica. A. anterior end, dorsal view, B. parapodium, setiger 7, C. parapodium, setiger 20, D. notosetae, shafts from setiger 7, E. neurosetae, shafts from setiger 7, upper bundle, F. neurosetae shafts from setiger 7, lower bundle, G. notosetae, shafts from setiger 10, H. neurosetae, shafts from setiger 10, I. notosetae from posterior setiger. Scale: A = 0.3 mm; B– C = 190 µm; D–I = 29 µm. Description.— Specimen complete with 49 setigers, 4.5 mm long and 0.3 mm wide without parapodia and setae. Alcohol-preserved specimen lacks pigment patterns, pale cream in color. Anterior 3–8 setigers with robust parapodia, after that gradually decreas- ing in size. Anterior end with pale golden setae and pale brown aciculae, rest of body with transparent aciculae and setae. Prostomium wider than long, without eyes, deeply incised in front, with pair of anten- nae as long as palps; palps with elongate palpostyles (Fig. 3A). Peristomium fused to 30 BULLETIN OF MARINE SCIENCE, VOL. 67, NO. 1, 2000 prostomium, as long as setiger 3. Four pairs of short tentacular cirri, posterior pair reach- ing back to setiger 3. Pharynx everted with three dorsal papillae on oral ring, and some ventral papillae difficult to see. Jaws serrated, slightly arched, pale brown in color, with 11 teeth. Parapodia of first two setigers uniramous, small, with filiform dorsal cirri and short bifid ventral cirri. Biramous parapodia with neuropodia more robust than notopodia. Notopodial presetal ligule elongated, acicular postsetal lobe conical. Neuropodia with broad lobe and small neuroacicular crescent papilla, and ventral ligule similar in shape and size to ventral cirri. Dorsal cirri elongated, with small cirrophore on first 8 setigers (Fig. 3B), from about setiger 9 to 20 with enlarged cirrophore, wider than style, with well-developed cilia continuing dorsally forming a transverse fringe (Fig. 3C). Parapodia of median region similar except presetal ligule shorter than dorsal cirri. Ventral cirri bifid to about setiger 20. In all parapodia setae homogomph and sesquigomph spinigers, blades smooth or slightly serrated; no strongly serrated setae. Notosetae and neurosetae with long and short blades (Fig. 3D–I). Remarks.—The single small specimen collected closely resembles Ceratocephale paci- fica (Hartman, 1960), however, the enlarged cirrophores of the dorsal cirri extends from setiger 9, rather than setiger 8 as stated original description, and the bifid ventral cirri are present from setiger 1 to about 20 in our individual, whereas in the original description they are reported from setiger 1 to about 25.

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