The most conspicuous elements in the catch of mesopelagic trawls are usually the orange-red decapod shrimps. Pelagic shrimps are predators or omnivores, and can utilize various kinds of food. They also play a significant role as food of fish and marine mammals. The feeding of pelagic shrimps may thus link zooplankton and large animals of the higher trophic levels in the food chains, and transports organic matter produced in the upper layers to the lower layers through vertical migrations.
By Tone Falkenhaug
Decapod shrimps constituted an important part of the biomass caught in trawls on the RV GO Sars MAR-ECO cruise in 2004. The large MAR-ECO decapod material includes samples from three different pelagic trawls, and one demersal trawl at 54 localities between Iceland and the Azores (60° - 41°N).
A workshop on pelagic decapod taxonomy was held at Institute of Marine Research, Flødevigen Research Station, Arendal, Norway 5 – 9 December, 2005. The participants was Prof. Endre Willassen (Bergen Museum, Norway), Prof. Marit Christiansen (Natural History Museum, Oslo, Norway), Hege Øverbø Hansen (Scientific technician, Institute of Marine Research, Flødevigen, Norway) and Tone Falkenhaug (Institute of Marine Research, Flødevigen, Norway).
The aim of the workshop was to facilitate and initiate the analysis work on the MAR-ECO decapod material, by
a) Compile relevant taxonomic literature
b) Training of scientists and technician in species identification
The analysis will continue beyond this workshop by involved scientists and technicians.
During the 5-days workshop, 41 samples were processed. So far 18 species within the following genera have been identified: Ephyrina, Systellaspis, Hymenodora, Oplophorus, Nostostomus, Meningodora, Hymenodora, Gennadas, Acanthephyra, Parapasiphae and Pasiphaea.