Title

Fishes of the Northern Mid-Atlantic Ridge Collected During the MAR-ECO Cruise in June/July 2004

Event Name/Location

EOS Trans. AGU Ocean Sciences Meeting, Honolulu, Hawaii, February 20-24, 2006

Document Type

Conference Proceeding

Publication Date

2-2006

Abstract

Deep-sea oceanic fishes were studied during the MAR-ECO 2004 cruise in mid-Atlantic Ridge (MAR). The pelagic and benthic biotopes were prospected with pelagic and bottom trawls to about 3500 m. The survey produced ca. 60000 specimens that were identified to at least 294 species. Several specimens of the families Bathylagidae, Oneirodidae, Cetomimidae, Syngnathidae, Ophidiidae, Psychrolutidae, Zoarcidae, may be new. The high incidence of rare species (e.g. Mirognathus normani; Ataxolepis sp., Gyrinomimus sp.)may be a good indication of the sampling extent. The pelagic layers are dominated by specialized small-body fishes. The samples (n=127) accounted for more than 50000 specimens of ca. 206 species, 57 families and 17 orders. Myctophiformes, Stomiiformes, Osmeriformes, Perciformes and Aulopiformes represented 74% of the species. The most speciose families were Myctophidae, Stomiidae, Alepocephalidae and Melamphaidae. In numbers the Gonostomatidae (i.e. Cyclothone spp.), Sternoptychidae and Bathylagidae dominated. In terms of biomass, important families included the Serrivomeridae and Platytroctidae. Benthosema glaciale, Cyclothone microdon, Bathylagus euryops, Lampanyctus macdonaldi, Serrivomer beanii,Maurolicus muelleri, dominated the collections, especially at the northern stations. The 22 bottom trawl samples collected ca. 175 species, in 52 families and 21 orders. Considering the typical demersal fishes, the Osmeriformes and Gadiformes dominated the samples (25 and 23 species). Alepocephalidae and Macrouridae were among the most diverse families (16 species), followed by Ophidiidae (7 species). Coryphaenoides rupestris, C. brevibarbis, and Haulosauropsis macrochir dominated the catches (50% of the individuals). The taxonomic composition of pelagic and demersal assemblages varies along the region studied. The pattern shows an increase of richness and a decrease in evenness and dominance toward lower latitudes. The sub-Polar Front is the major biogeographic boundary in the studied area.

Comments

Eos Trans. AGU, 87(36), Ocean Sci. Meet. Suppl.

Additional Comments

Identifier OS34G-02