The data file contains original data for two experiments described in the publication: Karvonen A., Klemme I., Räihä V., Hyvärinen P. 2023. Enriched rearing environment enhances fitness-related traits of salmonid fishes facing multiple biological interactions. Canadian Journal of Fisheries and Aquatic Sciences. doi 10.1139/cjfas-2023-0083. Authors and contact information: Anssi Karvonen, University of Jyväskylä, Finland, anssi.karvonen@jyu.fi Ines Klemme, University of Jyväskylä, Finland, ines.klemme@jyu.fi Ville Räihä, University of Jyväskylä, Finland Pekka Hyvärinen, Natural Resources Institute Finland (Luke), pekka.hyvarinen@luke.fi 1. Data file: experiment1.csv variables: fish_IDunique fish identifier for the passive integrated transponder of the experimental fish populationone of five fish populations of origin rearingone of two fish rearing treatments, either ‘standard’ or ‘enriched’ infectionone of two fish infection status, either uninfected (0) or infected (1) lengthbody length (mm), measured directly before stocking to experimental tanks cataractaverage percentage of cataract coverage across both eyes estimated directly before stocking to experimental tanks tankone of eight unique experimental tank identifiers for the experimental replicates predatorone of two predation treatments in the tanks, either predator absent (0) or predator present (1) ant_streambinary, detection of fish at the stream-side antenna in the tank, categorized as no detection (0) and detection (1) ant_poolbinary, detection of fish at the pool-side antenna in the tank, categorized as no detection (0) and detection (1), the latter indicating entry into the pool latency_entrylatency to the first entry into pool (hours since the start of the experiment) changesnumber of changes between the stream and the pool side of the experimental tank time_poolproportion of time spent in pool side of the tank throughout the experiment growthpercentage change in body length from the beginning until the end of the experiment survivalfish survival categorized as either not survived (0) or survived (1) 2. Data file: experiment2.csv variables: fish_IDunique fish identifier for the passive integrated transponder of the experimental fish populationone of five fish populations of origin rearingone of two fish rearing treatments, either ‘standard’ or ‘enriched’ infectionone of two fish infection status, either uninfected (0) or infected (1) lengthbody length (mm), measured before experiment 2 cataractaverage percentage of cataract coverage across both eyes tankone of four unique experimental tank identifiers for the experimental replicates timeone of two time points of recording measurements, March 2018 (1) and July 2018 (2) growthpercentage change in body length survivalfish survival categorized as either not survived (0) or survived (1)

2023