Crustacea, Amphipoda, Caprellidae

ARTICLE IN PRESS Organisms, Diversity & Evolution 7 (2008) 253e1–253e12 www.elsevier.de/ode A new species of Liropus (Crustacea, Amphipoda, Caprellidae) from Le Danois bank (southern Bay of Biscay) Jose´Manuel Guerra-Garcıáa,Ã, Jean Claude Sorbeb, Inmaculada Frutosc aLaboratorio de Biologıá Marina, Departamento de Fisiologıá y Zoologıá, Facultad de Biologıá, Universidad de Sevilla, Avda Reina Mercedes 6, 41012 Sevilla, Spain bLaboratoire d’Oceánographie Biologique (UMR 5805, CNRS/UB1), 2 rue Jolyet, 33120 Arcachon, France cInstituto Espanõl de Oceanografıá, Muelle de las A`nimas s/n, 15001 A Corunã, Spain Received 27 April 2005; accepted 10 April 2006 Abstract A new species of the genus Liropus (Crustacea, Amphipoda, Caprellidae) is described based on specimens collected from Le Danois bank (‘El Cachucho’ fishing grounds), Bay of Biscay. Liropus cachuchoensis n. sp. can be distinguished from all its congeners mainly by the absence of eyes and by the presence of a dorsal projection proximally on pereonites 3, 4 and 5 in males, on 3 and 5 in females. The new species has been found living on muddy bottoms on the southern flank of the bank and adjacent continental slope, between 619 and 1062 m depth, with a maximum abundance (56.1 ind./100 m2) recorded at 1044–1062 m. Morphological comparisons among the world’s members of Liropus, a key to species, and data on their distribution are presented. r 2007 Gesellschaft fu¨r Biologische Systematik. Published by Elsevier GmbH. All rights reserved. Keywords: Crustacea; Amphipoda; Caprellidae; Liropus; New species; Deep-sea Introduction and Sorbe 1996; Guerra-Garcıá 2003, 2004; Corbari et al. 2005). In this sense, the caprellids of the Bay of Caprellids are small marine crustaceans living from Biscay, the Atlantic Ocean area adjacent to the coasts of intertidal areas to deep-sea waters (McCain 1968; northern Spain and western France, have been studied Laubitz 1972; Guerra-Garcıá 2003). Most caprellids recently. In these surveys, the previously unknown occur epibiotically on various substrates such as algae, species Protoaeginella spinipoda (Laubitz and Sorbe seagrasses, hydroids, and bryozoans (Caine 1989), but 1996) was described, and the morpho-functional and several species live in more specific associations with behavioural adaptations to deep-sea bottoms of the invertebrates (Guerra-Garcıá 2001). Caprellids from caprellid Parvipalpus major Carausu, 1941 were explored deep waters have been investigated less than those from using video equipment (cf. Corbari et al. 2005). shallow waters. However, during the last years there has During recent suprabenthic sampling on Le Danois been an attempt to improve the taxonomical and bank and its surroundings (top plateau, southern flank ecological knowledge about deep-sea caprellids (Laubitz and adjacent Cantabrian slope), specimens belonging to an undescribed species of Liropus were collected at ÃCorresponding author. several stations during the ECOMARG 03 (October E-mail address: [email protected] (J.M. Guerra-Garcıá). 2003) and ECOMARG 04 (April 2004) cruises. In the 1439-6092/$ - see front matter r 2007 Gesellschaft fu¨r Biologische Systematik. Published by Elsevier GmbH. All rights reserved. doi:10.1016/j.ode.2006.04.002 ARTICLE IN PRESS 253e2 J.M. Guerra-Garcıá et al. / Organisms, Diversity & Evolution 7 (2008) 253e1–253e12 present work, this new species is described and Taxonomic section morphologically compared with the other members of the genus Liropus. Ecological information on the new Liropus cachuchoensis n. sp. species is presented, as well as a key and a distribution map for all Liropus species. Etymology Le Danois bank is locally called ‘El Cachucho’ by Spanish fishermen (Sańchez et al. 2002). Material and methods Material During the ECOMARG cruises, the suprabenthic Holotype: Male (MNCN 20.04/6072); NE Atlantic fauna was sampled at several stations from Le Danois Ocean, S Bay of Biscay, southern flank of Le Danois bank (Fig. 1, Table 1), using a suprabenthic sled bank; ECOMARG 03 cruise, RV ‘Vizconde de Eza’, 20 equipped with four plankton nets (0.5 mm mesh size) October 2003, 14:27–14:58 h, haul coordinates and with an opening–closing system activated by 44100.390N05109.420Wto44101.640N05109.970W, contact with the sea floor (for full description see Sorbe 854–816 m depth, water layer 0–50 cm above bottom, 1983). The superimposed nets allow quantitative sam- Arcachon suprabenthic sled, sample reference E03- pling of the motile fauna in two water layers (0–50 and TS8b; water temperature 12.8 m above bottom (CTD 50–100 cm; lower/upper net codes: a–b/c–d) above the data) 10.3 1C, salinity 35.8%; sandy mud sediment, sea floor. The sled was towed at approx. 1.5 knots over median grain size 28.2 mm; silt and clay (o62 mm) the bottom during each haul. The volume of water 64.93%, fine to medium sand (62–500 mm) 34.42%, filtered by the nets (in m3) and the bottom area sampled 2 coarse sand (4500 mm) 0.65%, organic content 6.26% by the sled (in m ) were estimated from the values given of sediment dry weight. by a TSK flowmeter placed in the opening of the right Paratypes: Allotype female (MNCN 20.04/6073); upper net (see also Cunha et al. 1997). The collected three males, three females, one juvenile (MNCN 20.04/ suprabenthic fauna was fixed on board with 10% 6074). Data as for holotype. neutral formalin, then sorted under a dissecting micro- Additional material: Two males and two females scope. The Liropus specimens were identified and (MNHN-Am 5835); ECOMARG 04 cruise, RV ‘Viz- counted. Their abundance was expressed as the number 3 conde de Eza’, 14 April 2004, 10:42–11:23 h, haul of individuals per 100 m for the 0–50 and 50–100 cm coordinates 43158.300N05110.820Wto43157.730N water layers, and as the number of individuals per 1 0 2 05 09.25 W, 831–828 m depth, water layer 0–50 cm 100 m for the 0–100 cm water layer. above bottom, Arcachon suprabenthic sled, sample Selected specimens were dissected under an Olympus reference E04-TS2a; water temperature 14 m above dissecting microscope. All dissected appendages were bottom (CTD data) 10.2 1C, salinity 35.8%; sandy mounted in polyvinyl–lactophenol. The figures were mud sediment, median grain size 21.6 mm; silt and clay drawn using a Leica compound microscope equipped 69.58%, fine to medium sand 29.07%, coarse sand with a camera lucida. 1.34%, organic content 7.00% of sediment dry weight. For morphological comparisons, material from the Museúm National d’Histoire Naturelle (MNHN), Paris, Diagnosis and from the United States National Museum (USNM), Eyes absent. Acute anterolateral projections on head Washington, DC, was examined. Specimens of the new and pereonite 2. Dorsal projection proximally on species have been deposited in the Museo Nacional de pereonites 3, 4 and 5 in males, on 3 and 5 in females. Ciencias Naturales (MNCN), Madrid, and at MNHN. Flagellum of antenna 1 with more than two articles. The phylogeny and higher classification of the Pereopods 3 and 4 one-articulate; pereopod 5 two- caprellids is still being debated (see Laubitz 1993; articulate. Male abdominal appendages vestigial. Takeuchi 1993). Recently, Myers and Lowry (2003) have proposed a new phylogeny and classification for the suborder Corophiidea Leach, 1814, which is divided Description into two infraorders, the Corophiida and the Caprellida, based on an hypothesis of the evolution of different Male (holotype, 5.3 mm) feeding strategies. According to this classification, the Lateral view (Fig. 2): Head rounded, with a pair of superfamily Caprelloidea contains five families: Caprel- acute anterolateral projections; eyes absent. Pereonite 1 lidae, Caprogammaridae, Cyamidae, Dulichiidae, and fused with head, suture present. Pereonite 2 with a pair Podoceridae. The Caprellidae are subdivided into three of anterolateral projections and another pair of small, subfamilies: Caprellinae, Paracercopinae, and Phtisici- acute projections near coxae of gnathopods 2. Pereo- nae. The genus Liropus is included in the subfamily nites 3, 4 and 5 each with a dorsal projection proximally. Caprellinae Leach, 1814. Pereonite 5 the longest, pereonite 7 the shortest. ARTICLE IN PRESS J.M. Guerra-Garcıá et al. / Organisms, Diversity & Evolution 7 (2008) 253e1–253e12 253e3 Fig. 1. Geographic locations of seven stations sampled with a suprabenthic sled on Le Danois bank and the adjacent Cantabrian slope during ECOMARG 03 (squares) and ECOMARG 04 (circles) cruises. Solid symbols: samples including Liropus cachuchoensis n. sp. Isobaths in metres. Table 1. Haul characteristics and abundance of the caprellid Liropus cachuchoensis n. sp. in the 0–50 cm, 50–100 cm [ind./100 m3], and 0–100 cm [ind./100 m2] near-bottom water layers at seven stations sampled with a suprabenthic sled on Le Danois bank during the ECOMARG 03 and ECOMARG 04 cruises Haul code Date (d/m/y) Timea (h:min) Positiona Depthb (m) Abundance N W 0–50 cm 50–100 cm 0–100 cm E03-TS1 15/10/03 09:43 44103.960 4152.330 486/486 0.0 0.0 0.0 E03-TS2’ 16/10/03 11:34 44104.880 4149.310 507/499 0.0 0.0 0.0 E03-TS8 20/10/03 14:27 44100.390 5109.420 854/816 27.2 2.7 15.2 E04-TS1 13/04/04 13:00 44100.470 5108.080 828/829 64.9 0.0 32.9 E04-TS2 14/04/04 10:42 43158.300 5110.820 831/828 8.5 0.3 4.5 E04-TS3 15/04/04 09:34 43151.470 5106.760 620/619 1.0 0.0 0.5 E04-TS4 16/04/04 12:01 43154.860 4155.100 1044/1062 105.0 5.7 56.1 aAt beginning of haul.

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