4FatQs

The importance of dietary omega-3 fatty acids for development of cognitive sk ills in wild fishes through the lens of Tinbergens four essential questions (4FatQs) The physiological dependence of animals on a diversity of vital dietary biomolecules such as vitamins, amino acids andfatty acids is ubiquitous. Omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) are vital biomolecules and their dietary intake is necessary for survival and reproduction many vertebrates from fishes to humans. However, how dietary n-3 LC-PUFA influence brain biochemical and cellular composition and what is their impact on cognition and ecologically important behaviour remains largely unknown.In fact, we have only begun to understand how strong differences in the availability of vital dietary biomolecules across food webs can force animal consumers to adopt a range of strategies including behavioural, physiological, neural, and life-history traits to satisfy their needs for these biomolecules. Anthropogenic pressures such as climate change, eutrophication, or biological invasions are predicted to cause rapid changes the amount of available essential fatty acids in aquatic ecosystems. Theses change will likely have particularly serious consequences for top consumers in these ecosystems such as stream dwelling salmonid fishes. Therefore, there is an urgent need to understand how do wild fish cope with changes in availability of essential fatty acids in their diet. The aim of 4FatQs project is to use the framework of four essential equations proposed by a Nobel Price winner Nikolass Tinbergen to understand how availability of n- 3 LC-PUFA in diet affects development and evolution of brain in an experimental system of European stream-dwelling salmonids. Specifically, we will look into how diet quality affect changes density of neurons in the fish brain and how are these changes in the brain quality related to cognitive skills and behaviour of individuals. We will also explore how individuals from different populations response to the changes in availability of these vital dietary biomolecules, which will help us to understand how local fine scale evolutionary adaptations influence sensitivity of individuals to quality of their diet. This project combines field and laboratory experiments, while utilising aspects of biochemistry, behavioural ecology, neurobiology, and evolutionary biology. The results of this research will substantially advance the field of cognitive and ecological research as it is the first study that will link, at the individual level, the availability of vital dietary biomolecules with brain biochemical and cellular composition, cognitive skills, personality traits, ecological niche of wild animals. While answering fundamental ecological and evolutionary questions, the knowledge that will be acquired during this project has practical applications with regards to the management of wild fish populations as well as for welfare of fish in aquaculture.