Search results for "food-chain length"
showing 2 items of 2 documents
Lake size and fish diversity determine resource use and trophic position of a top predator in high-latitude lakes
2015
Prey preference of top predators and energy flow across habitat boundaries are of fundamental importance for structure and function of aquatic and terrestrial ecosystems, as they may have strong effects on production, species diversity, and food-web stability. In lakes, littoral and pelagic food-web compartments are typically coupled and controlled by generalist fish top predators. However, the extent and determinants of such coupling remains a topical area of ecological research and is largely unknown in oligotrophic high-latitude lakes. We analyzed food-web structure and resource use by a generalist top predator, the Arctic charr Salvelinus alpinus (L.), in 17 oligotrophic subarctic lakes…
Trophic ecology of piscivorous Arctic charr (Salvelinus alpinus (L.)) in subarctic lakes with contrasting food-web structures
2019
The trophic ecology of piscivorous Arctic charr (Salvelinus alpinus (L.); charr) in the food webs of large subarctic lakes is not well understood. We assessed charr diets, parasites, growth, maturity, and stable isotope ratios in Fennoscandian subarctic lakes dominated by monomorphic or polymorphic whitefish (Coregonus lavaretus (L.)) populations. Charr density was low in all lakes, except in profundal habitats. Charr shifted to piscivory at small size (16–25 cm total length) and consumed a range of prey-fish sizes (2–25 cm). Cannibalism was observed in a few individuals from one monomorphic whitefish lake. Charr matured at 37–51 cm (5–8 years old), grew to 52–74 cm maximum observed length …