Feeding strategies and energy requirements of deep-sea demersal fish in the Eastern Mediterranean.

This research project, carried out between 1998-2003, was aiming to describe the structure and functioning of the deep fish community in the southern Ionian Sea. The study area was the same with the previous project. The studied species were G. melastomus, E. spinax, Coelorhynchus coelorhynchus, Hymenocephalus italicus, Nezumia sclerorhynchus, H. mediterraneus, H. dactylopterus and L. boscii.

Three major groups were identified in the examined demersal assemblage (benthic feeders, pelagic feeders and mixed diet species). The dominant species were pelagic feeders. Season was the main identified factor influencing both fish assemblage composition and biomass, while no differences were found with depth. Food availability was the main factor affecting the studied demersal assemblage. Diel patterns involved mesopelagic and suprabenthic prey via circadian migratory movements of these organisms. Food resources were well partitioned among the co-existing demersal fish species of the bathyal-eastern Ionian Sea. This partitioning was mainly determined by fluctuations in prey availability and by prey size. Overall results underline the importance of mesopelagic decapods in the dynamics of food webs of the studied fish community (MADURELL, 2003). [DG/XII-XIV/EU/FAIR-CT97/1376]