The effects of different combinations of nutritional background, feeding regimes and dietary compositions on growth responses of the Atlantic cod have been examined Alternating short periods (1-3 weeks) of food deprivation with unlimited prowslon of food depressed growth below that of controls, but cod that were fed on alternate weeks (1 1) were larger than those that were exposed to 2 or 3 week periods of deprlvahon and feeding (2 2 or 3 3) Thus, periods of food deprwatmn of short duration were insufficient to reduce any marked compensatory growth response When cod were deprived of food for longer periods a compensatory growth response was observed On receiving excess food supplies following 8 weeks of food deprivation the fish grew more rapidly than the controls and had completely recovered body weight within 12 weeks The greatest compensatory growth response was shown by cod in poor condition (lowest condition factor), because at the end of an 18 week growth trial there were no differences In body weight between fish irrespectwe of their initial condition Both sexes displayed a compensatory growth response

Gelatinous zooplankton hold key functions in the ocean and have been shown to significantly influence the transport of organic carbon to the deep sea. We discovered a gelatinous, flux‐feeding polychaete of the genus Poeobius in very high abundances in a mesoscale eddy in the tropical Atlantic Ocean, where it co‐occurred with extremely low particle concentrations. Subsequent analysis of an extensive in situ imaging dataset revealed that Poeobius sp. occurred sporadically between 5°S–20°N and 16°W–46°W in the upper 1000 m. Abundances were significantly elevated and the depth distribution compressed in anticyclonic modewater eddies (ACMEs). In two ACMEs, high Poeobius sp. abundances were associated with strongly reduced particle concentrations and fluxes in the layers directly below the polychaete. We discuss possible reasons for the elevated abundances of Poeobius sp. in ACMEs and provide estimations showing that a single zooplankton species can completely intercept the downward particle flux by feeding with their mucous nets, thereby substantially altering the biogeochemical setting within the eddy.

During 3 cruises to the West European Basin benthopelagic nekton was captured by use of an acoustically released vertical array of 8 to 10 baited traps. The traps were exposed from 5 to 1000 m above the bottom. Nearly all of the 1692 amphipods trapped in total during 18 deployments were identified as the lysianassid amphipod Eurythenes gryllus Lichtenstein. Most individuals were recovered from traps deployed 15 m above the sea floor. Above 30 m, catch rates decreased significantly. However, the vertical distribution differed by age and sex: indeterminate juveniles and adult females were only trapped up to 50 m above the bottom Catch rates of juvenile males and females decreased with increasing distance from the bottom, whereas adult males showed a bimodal distribution with maxima at 15 and at 300 m above the sea floor. Males were prevalent in all but 2 deployments. The characteristic vertical distribution and the population structure at the depths sampled imply an ontogenetic vertical migration of E. gryllus females release their brood near the bottom. The youngest stages stay within a few meters above the sea floor, whereas older stages, especially adult males, migrate into higher water layers.

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