Líffræðifélag Íslands
Líffræðiráðstefnan 2015
Erindi/veggspjald / Talk/poster E105
Christian Beuvard (1), Helgi Thorarensen (1)
Háskólinn á Hólum
Kynnir / Presenter: Christian Beuvard
Tengiliður / Corresponding author: Christian Beuvard (christian@mail.holar.is)
Changes in ambient temperature affect the physiology and metabolism and thus the distribution of fish. In this study we determined the effect of temperature (5, 9, 13, 17 and 21 °C) on growth rate and, by using intermittent flow respirometry, on metabolic rates such as standard metabolic rate (SMR), routine metabolic rate (RMR), maximum metabolic rate (MMR) and metabolic scope (MS, difference between MMR and SMR) of juveniles Arctic charr. After 96 days of experiment the mortality was high for the fish at 21°C where 60% of the fish died. This finding is following previous results were the upper thermal limit for Arctic charr was situated around 21 to 24°C. Fish at 13°C had the highest specific growth rate and increase in body mass of all conditions while fish at 21°C expressed almost no growth with an increase of 1g in 96 days. SMR, RMR and MMR were all increasing with the increase in rearing temperature. Fish at 13°C had the highest value of metabolic scope whereas fish at 5°C had the lowest MS. This is following the general statement where the temperature optimum for growth (Topt) is linked to the metabolic scope. However, fish at 21°C had the second highest MS of all the groups and this without any gain on growth. This result contradicts the general view where the MS is decreasing after the Topt and gives new perspectives to study the relation between growth and metabolic scope.Changes in ambient temperature affect the physiology and metabolism and thus the distribution of fish. In this study we determined the effect of temperature (5, 9, 13, 17 and 21 °C) on growth rate and, by using intermittent flow respirometry, on metabolic rates such as standard metabolic rate (SMR), routine metabolic rate (RMR), maximum metabolic rate (MMR) and metabolic scope for activity (MS, difference between MMR and SMR) in juveniles of Arctic charr. After 96 days of experiment, the mortality was the highest for the fish at 21°C where 60% of the fish died. This finding is following previous results were the upper thermal limit for Arctic charr is situated around 21 to 24°C. Fish at 13°C had the highest specific growth rate and increase in body mass of all conditions while fish at 21°C expressed almost no growth (1g in 96 days). SMR, RMR and MMR were all increasing following the increase in rearing temperature. Fish at 13°C had the highest value of metabolic scope whereas fish at 5°C had the lowest MS. This is following the general statement where the temperature optimum for growth (Topt) is linked to the metabolic scope. However, fish at 21°C had the second highest MS of all the groups and this without any gain on growth. This result contradicts the general view where the MS is decreasing after the Topt and gives new perspectives to study the metabolic scope for activity in fish. Key words : Rearing temperature, Growth rate, Metabolism scope, Arctic charr