Premium
Genetic and Environmental Influences on Life History Traits in Lake Trout
Author(s) -
McDermid Jenni L.,
Ihssen Peter E.,
Sloan William N.,
Shuter Brian J.
Publication year - 2007
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/t06-189.1
Subject(s) - salvelinus , trout , biology , hatchery , juvenile , life history theory , ecology , juvenile fish , fishery , life history , zoology , fish <actinopterygii>
Lake trout Salvelinus namaycush exhibit substantial life history variation associated with variation in climatic and biotic variables. To assess the environmental and genetic influences on lake trout life history traits, eggs were collected from two lakes in Algonquin Park, Ontario, Lake Opeongo and Louisa Lake, with contrasting ecotypes and forage bases. Eggs from both populations and interpopulation hybrids (Lake Opeongo females × Louisa Lake males) were raised to maturity in a common controlled environment. There was evidence of a genetic basis to life history variation between ecotypes. Hatchery‐reared lake trout from Louisa Lake were found to have a faster prematuration growth rate and earlier age and smaller size at maturation than Lake Opeongo lake trout, whereas Lake Opeongo lake trout had greater postmaturation growth rates. Most of the life history traits of hybrids were intermediate between those of the parent populations. These differences were also consistent with reported differences on these populations in the field. Despite differences in maturation and body size, reproductive investment did not differ significantly among the hatchery‐reared populations. There was also evidence of phenotypic plasticity in growth (juvenile and adult) and age at maturity. For fish originating from each lake, hatchery‐raised fish showed higher prematuration growth rates and younger ages at maturity than did wild fish. Hatchery‐reared fish from Louisa Lake were projected to attain asymptotic sizes nearly 50% larger than those of their wild counterparts. These data provide evidence that wild lake trout populations exhibit a plastic response to resource limitation. The combined results of this study indicate that lake trout life history characteristics are driven by both genetic and environmental influences, which should be incorporated into current life history models and used in making management decisions.