Abstract
Selective breeding of salmonid fishes for the purpose of commercial aquaculture has resulted in domesticated strains possessing a divergent physiological and behavioral phenotype from that of wild conspecifics. Freshwater production of rainbow trout (Oncorhynchus mykiss) has been occurring in regions of Lake Huron, Canada, for decades yet the growth and performance of domestic (aquaculture) versus wild (naturalized) strains are poorly understood. We conducted two trials to examine growth differences between size-matched wild and domestic strains of juvenile rainbow trout: (1) reared separately and fed to satiation; and (2) reared together and fed a reduced ration to induce competition. Additionally, we used bioenergetics models to assess strain-specific growth rates across a range of water temperatures (5, 10, 15 and 18°C) as well as Lake Huron temperatures during the open-water season. Domestic rainbow trout showed a growth advantage throughout the 102d trials, and by the end of the study had achieved a mass >two-fold that of the wild strain and had greater fork length, condition, and thermal growth coefficient (TGC) under both treatments. Rapid growth of domestic strain fish was achieved through the combination of enhanced feed consumption (by ~40%) and feeding efficiency (up to 60% lower feed conversion ratio) relative to wild fish. Divergence in growth rates between strains was most pronounced (>3×) when modeled with Lake Huron open-water temperatures. We demonstrate that the growth and feed-conversion efficiency differ significantly between these two strains of rainbow trout under laboratory conditions, suggesting that differences could be even greater in nature.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.