The average global temperature is expected to rise by 3-5 °C at the end of the century, as a consequence of global warming. Negative effects are expected on poikilothermic animals, including fish, with changes in their physiology including metabolism. Metabolism has earlier been proven to have an association with propensities to migrate, which might be affected by raised temperatures as a consequence of global warming. The purpose of this study was to investigate if raised temperatures during incubation of eggs has an effect on metabolism in a partly migrating species of fish. The hypotheses for this study were: (i) ventilation rate (VR) will decrease as a consequence of warmer incubation temperatures, and (ii) offspring of anadromous parents are expected to have a higher VR compared to offspring of residential parents. VR, as a proxy for metabolic rate, was measured on young-of-the-year brown trout (Salmo trutta) during trials in respiration chambers. Fertilized eggs from four different crossings of parents (anadromous x anadromous, residential x residential, anadromous male x residential female, residential male x anadromous female) underwent incubation in normal and warm (normal + 3 °C) water temperatures respectively. A Two-way ANOVA showed a significant interaction between incubation temperature and crossing on VR. Warmer incubation temperatures in 3 out of 4 crossings resulted in a higher VR, except for individuals with two anadromous parents. Individuals with an anadromous father had a higher VR than individuals with a residential father. Evidence that partly supports both hypotheses was therefore found. Metabolism might have a strong genetic component, and other factors that might have an effect on metabolism and VR are epigenetics, stress, egg size etcetera. Studies of this kind will be of importance in getting a greater understanding of the effects of global warming on migrating species of fish, and on poikilothermic vertebrates in general.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kau-72934 |
| Date | January 2019 |
| Creators | Vernby, Andreas |
| Publisher | Karlstads universitet, Institutionen för miljö- och livsvetenskaper (from 2013) |
| Source Sets | DiVA Archive at Upsalla University |
| Language | Swedish |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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