Abstract

Size is a crucial factor affecting the survival of fish during winter. Pond and laboratory experiments with three size classes of perch (small: 40-70 mm, medium: 71-100 mm, large: 101-186 mm) revealed that the feeding history of perch prior to winter is reflected in the amount and type of accumulated energy reserves. The minimal amount of reserves was 2% of the perch's biomass for fat and 9% for protein. An increase in glycogen levels either reflected mobilisation of energy in the body when perch were starving or an increase in accumulated energy over winter. In the laboratory, only the smallest perch suffered from high mortality rates, even if all were fed with low amounts of food. However, feeding the fish reduced the mortality rate after a certain time lag. Size-selective mortality rates occurred in the pond experiments as well. Small perch which survived the winter were able to rebuild their energy stores.

Keywords

winter-mortality; energy stores; feeding activity; Perca fluviatilis

Published in

Ecology of Freshwater Fish
2009, Volume: 18, number: 4, pages: 560-571

SLU Authors

• Eriksson, Lars-Ove

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    

• Magnhagen, Carin

  • Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Fish and Aquacultural Science


Publication identifier

DOI: https://doi.org/10.1111/j.1600-0633.2009.00371.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/26684