Effekter av inkuberingstemperatur hos juvenil atlantlax (Salmo salar L.)

• Main Author: Adolfsson, Oscar
• Format: Bachelor Thesis
• Language: Swedish
• Published: Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013) 2018
• Subjects: Climate change; salmon; body shape; parr; Lax; Klimatförändringar; kroppsform; Ecology; Ekologi; Atlantic salmon; Salmo salar
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-67269

Rising temperatures, because of climate change, will have major consequences for the world's fish populations, including the Atlantic salmon Salmo salar L. The greatest temperature changes are expected to occur during winter, which will affect S. salar since the eggs are developing during this time of year. Several studies have shown that elevated temperatures during embryogenesis cause morphological changes, in S. Salar, that are shown in later life stages. Some of these studies indicate that eggs incubated at high temperatures should generate parr with deeper bodies. To investigate whether high temperatures during the egg stage cause changes in body shape, parr from normal and high temperature incubated eggs, referred to as as “cold” and “warm” fish, respectively, were examined. A box-truss of euclidean distances between 10 landmarks on the fish body and a discriminant function analysis (DFA) was used to determine which of the distances best discriminated between the two groups. The test showed a significant discrimination between cold and warm parr regarding body shape where cold parr had greater heads and warm parr were deeper over the tail region and showed greater distances between the pelvic fin and the front attachment of the anal fin. 67,3 % of all parr where correctly classified by the test. These results support those notions that indicates that the incubation temperature is important for the morphological development of S. salar although it does not support the hypothesis. Stigande temperaturer, till följd av klimatförändringar kommer att få stora konsekvenser för jordens fiskpopulationer, däribland atlantlaxen Salmo. Salar L. Störst temperaturförändringar väntas ske vintertid, vilket kommer att påverka S. Salar som övervintrar sin rom. Flera studier har visat att förhöjda temperaturer under embryogenesen ger upphov till morfologiska förändringar hos S. Salar under senare livsstadier. Några studier pekar mot att högtemperaturinkuberad rom torde ge upphov till parr med djupare kroppsform. För att ...