Maturation, growth and fecundity of Arctic charr, Salvelinus alpinus (L.), life-history variants co-existing in lake systems of Southern Baffin Island, Nunavut, Canada

Abstract

Two life-history variants of Arctic charr (Salvelinus alpinus), anadromous and lake-resident, have been previously identified in lakes of Southern Baffin Island, Nunavut, Canada. In accordance with classical life-history theory, it is hypothesised that anadromous charr will delay maturation in both size and age, and have increased fecundity (per spawning event) in comparison with lake-resident charr. Sagittal otoliths and biological data were collected for both life-history variants within the three studied lakes: Iqalugaarjuit, Qasigiat and Qinngu. Sagittal otoliths were embedded in epoxy resin, cross-sectioned for age determination, and imaged for back-calculation (size and age). Back-calculated data in each lake were fit to von Bertalanffy growth models for each life-history variant and compared via analysis of residual sums of squares. Anadromous charr had greater mean size at maturity and experienced a delay in mean age at maturity in comparison with lake-residents. The relationship between size and fecundity or egg diameter did not differ between the two life-history variants. Growth models indicate that the overall growth coefficients of lake-resident and anadromous charr were different in all three studied lakes. The Brody growth coefficient for all lake-resident charr populations was greater than anadromous individuals indicating that maximum length was reached at a rapid rate, resulting in a smaller asymptotic length. Indirect evidence suggests that anadromous and lake-resident charr belong to one reproductive population. Future genetic analysis is necessary to further determine the degree of divergence between the life-history variants.

Anadromous char as an alternate food choice to marine animals: A synthesis of Hg concentrations, population features and other influencing factors

“…More recent studies have investigated population and genetic structure of anadromous char Loewen et al, 2009;Loewen et al, 2010;Moore et al, 2013). Capelin (Mallotus villosus) has become prevalent in the past decade causing anadromous char to shift from feeding primarily on zooplankton to feeding on these fish (Ulrich, 2013).…”

Marine trophic niche use and life history diversity among Arctic charrSalvelinus alpinusin southwestern Greenland

“…Degree of maturation was determined by visual inspection of the gonads following Loewen et al . (). Sagittal otoliths were removed and stored dry in envelopes for age determination while stomach contents were preserved in 96% ethanol for further examination.…”

“…Overview of the study areas of Kapisillit, Equalit and Quinqua watercourses in south-western Greenland DAVIDSEN ET AL. 683Degree of maturation was determined by visual inspection of the gonads followingLoewen et al (2010). Sagittal otoliths were removed…”

Time series data for Canadian arctic vertebrates: IPY contributions to science, management, and policy

“…In addition to its extraordinary importance to the arctic ecosystem, Arctic char is highly valued by Inuit and Aboriginal harvesters. Samples obtained along a 37 o latitudinal span (IPY-CVCC) indicated differences in length-at-age and age-specific growth rate and that fecundity varied with latitude, morphotype, life-history, and climate (Power et al 2005;Chavarie et al 2010;Loewen et al 2010). Commercial fisheries for Arctic char in Cambridge Bay Nunavut commenced in 1960 and biological information was collected through fish plant sampling since 1971 (Day and de March 2004) providing a sporadic monitoring of relative abundance.…”