density-dependent processes in the life history of fishes evidence from laboratory populations of zebrafish danio rerio密度制约的过程从实验室鱼类生活史的证据的数量斑马鱼鲐鱼类.pdfVIP

Density-Dependent Processes in the Life History of Fishes: Evidence from Laboratory Populations of Zebrafish Danio rerio 1,2,3 1,3 4 4 2 Charles R. E. Hazlerigg *, Kai Lorenzen *, Pernille Thorbek , James R. Wheeler , Charles R. Tyler 1 Division of Biology, Imperial College London, Ascot, United Kingdom, 2 Ecotoxicology and Aquatic Biology Research Group, University of Exeter, Exeter, United Kingdom, 3 Fisheries and Aquatic Sciences, School of Forest Resources and Conservation, University of Florida, Gainesville, Florida, United States of America, 4 Syngenta, Environmental Safety, Jealott’s Hill International Research Centre, Bracknell, United Kingdom Abstract Population regulation is fundamental to the long-term persistence of populations and their responses to harvesting, habitat modification, and exposure to toxic chemicals. In fish and other organisms with complex life histories, regulation may involve density dependence in different life-stages and vital rates. We studied density dependence in body growth and mortality through the life-cycle of laboratory populations of zebrafish Danio rerio. When feed input was held constant at population-level (leading to resource limitation), body growth was strongly density-dependent in the late juvenile and adult phases of the life-cycle. Density dependence in mortality was strong during the early juvenile phase but declined thereafter and virtually ceased prior to maturation. Provision of feed in proportion to individual requirements (easing resource limitation) removed density dependence in growth and substantially reduced density dependence in mortality, thus indicating that