Title

Preliminary Results on Feeding Ecology of Stomiiform Fishes of the Northern Mid-Atlantic

Event Name/Location

ASLO Ocean Sciences Meeting, Portland, Oregon, February 22-26, 2010

Document Type

Poster

Publication Date

2-2010

Abstract

Few previous studies have focused specifically on the role of the mid-ocean ridges in the ecology of pelagic fishes. This study centers on a dominant nekton component of the mid-Atlantic mesopelagic ichthyofauna - the Stomiiformes - and their food resources including zooplankton and other nekton. Its main goal is to characterize the diets of several species of these midwater fishes towards understanding the trophic pathways of the deep-pelagic nekton of the northern Mid-Atlantic Ridge. The study material was provided by the 2004 G. O. Sars Expedition under the international project MAR-ECO. In the lab fishes were dissected and diet items were identified to the lowest taxonomical level possible. Preliminary results for 9 of the 12 species proposed for this study are presented. Amphipoda and Pteropoda seem to be important in Argyropelecus aculeatus feeding, while in Sternoptix diaphana amphipods are clearly the most common prey. Of the identifiable items in the guts of Maurolicus muelleri, Argyropelecus hemigymnus and Vinciguerria attenuata copepods constituted half of the occurrences but ostracods are also relevant. These four species show more planktivorous affinities when compared with the remaining species. Cyclothone microdon and Sigmops bathyphilum had the fewest identifiable items in the guts. C. microdon stomachs were not completely empty but frequently had a mass of unidentifiable jelly-like material. This may indicate that this species eats gelatinous plankton. Identifiable prey items from Stomias boa suggest a piscivorous behaviour. Malacosteus niger is also a predator but occasionally eats copepods. Future work includes study of three more species: Sigmops elongatum, Borostomias antarcticus and Chauliodus sloani and more detailed analyses for all the target species, consisting of determination of prey biomass and feeding guilds, calculation of daily ration and predation impact of the midwater fish assemblage on their prey in an attempt to design a food web model of the nekton community associated with the Mid-Atlantic Ridge.

Comments

Eos Trans. AGU, 91(26), Ocean Sci. Meet. Suppl.

Additional Comments

Identifier BO25E-03