科研之友
微信
新浪微博
Facebook
分享链接
摘要
Otolith carbon and oxygen isotope data obtained from distinct genetic and ecological groups of lacustrine Arctic charr, Salvelinus alpinus L., from Gander Lake, Newfoundland, were used to examine hypotheses regarding the consistency of differential habitat use among the groups. Results indicated thermal habitat separation by group, with small pale individuals consistently remaining in cooler profundal habitats and larger dark individuals more frequently occupying warmer upper water column habitats. Theoretical measures of resource separation and competition indicated lower thermal habitat overlap among the forms and greater within-form competition. Depth at capture data indicated more varied short-term use of available lake habitats by dark form Arctic charr, possibly as a result of cannibalistic foraging on profundal pale form fish. Nominal capture depth data only partially explained observed variation in the mean temperature of occupied thermal habitat, suggesting that capture depth can only be used as a rough index of thermal habitat use. Provided that sufficient thermal gradients exist in the environments being studied, otolith oxygen isotopes provide a useful means of establishing the significance of niche differentiation among individuals.
- 出版日期2012-4
