Search results for "VDP::Mathematics and natural science: 400::Zoology and botany: 480"
showing 3 items of 33 documents
Embryonic development of corkwing wrasse, Symphodus melops
2016
Master's thesis Aquatic Ecology BIO500 - University of Agder 2016 Eggs from corkwing wrasse, Symphodus melops were described, photographed and illustrated to characterise the embryonic development of this species. Egg development was divided into 8 stages from fertilisation until hatching with descriptions of key features for each stage. The rate of development in corkwing wrasse eggs at temperatures commonly found along the Norwegian coast (12, 15 and 18 C) was also investigated. The rate of development was faster at higher temperatures. Keywords: labridae, cleaner fish, embryonic development, corkwing wrasse
Probabilistic maturation reaction norms assessed from mark-recaptures of wild fish in their natural habitat
2014
Published version of an article in the journal: Ecology and Evolution. Also available from the publisher at: http://dx.doi.org/10.1002/ece3.1044 Open Access Reaction norms are a valuable tool in evolutionary biology. Lately, the probabilistic maturation reaction norm approach, describing probabilities of maturing at combinations of age and body size, has been much applied for testing whether phenotypic changes in exploited populations of fish are mainly plastic or involving an evolutionary component. However, due to typical field data limitations, with imperfect knowledge about individual life histories, this demographic method still needs to be assessed. Using 13 years of direct mark-recap…
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…