Nematode genera abundance from Portuguese canyons HERMES HERMIONE

Study Extent

cf. sampling description

Sampling

All the data has been made publicly available through the Pangaea data depository (www.pangaea.de) in the past; DOI codes for data are 10.1594/PANGAEA.776602 10.1594/PANGAEA.776656 10.1594/PANGAEA.777030 10.1594/PANGAEA.777032 10.1594/PANGAEA.777033 10.1594/PANGAEA.776716 The samples cover 3 canyon systems along the Western Iberian Margin, sampled by means of a coring device (Megacorer: Corer fitted with 60mm (internal diameter) plexiglass cores (Ocean Scientific International Ltd) and MUC: Barnett-type multicorer) all producing sediment cores with an intact sediment-water interface and similar crosssurface areas (maximum difference between sample surfaces was ca. 2.7 cm2). This allowed comparison between samples irrespective of the sampling technique used. At each of the 4 canyon/slope areas, cores were taken at two different stations (ca. 3400 and 4300m). At each location, a minimum of three independent (repeated deployments of the coring device) cores were taken which lay 1 to 200m apart. Each sediment core was subsequently split into 1 cm layers down to 5 cm vertical depth, whereby each 1 cm slice was treated independently. On some occasions, only the surface 1 cm of sediment was available. Borax-buffered formalin (4 %) sediment samples were used to extract the meiofauna using standard procedures (Heip et al., 1985; 32–1000 μm sieves, LUDOX HS as centrifugation medium) to separate the organisms from the sediment particles. All nematodes were counted and between 100 and 150 individuals were picked out randomly from each 1 cm sample, transferred to glycerine (Seinhorst, 1959) and mounted on slides.

Quality Control

All nematodes were identified under a compound microscope (100× magnification) to genus level using Platt and Warwick (1988), taxonomic literature of the Nematode Library at Ghent University, and the NeMys nematode database and identification keys (Deprez et al., 2005; nemys.ugent.be). Specimens that could not be identified to the genus level were assigned to the appropriate higher taxon level.

Method steps

1. n/a - see above

Free-living Nematoda (nematodes, roundworms)identified to genus level

1. Nematoda
   common name: roundworms rank: phylum

Nazare, Setubal and Cascais submarine canyons (3200-4500m water depth)