Comparison of the growth performance of offspring from cultured versus wild populations of arctic charr,Salvelinus alpinus(L.), kept at three different temperatures

Abstract

The effects of three different temperatures on the growth and maturation of the offspring of cultured versus wild populations of juvenile arctic charr (Salvelinus alpinus L.) were investigated. The fish (start weight 17 g) were reared for 5 months at constant temperatures of 12, 14 and 16°C under a continuous light regime (LD24:0). Growth performance was significantly influenced by both temperature and source population. The offspring from the farmed fish displayed significantly higher mean weights at all temperatures compared with the offspring from the wild fish. The results indicate that the optimal temperature for growth (T opt ) decreases with increasing fish size in the offspring of both cultivated and wild fish. Significant differences in length-weight relationship were found, with the offspring of wild fish displaying higher condition factor throughout the experiment. The results demonstrate that the offspring from multiple generation farmed population of arctic charr are better adapted to high temperatures compared with the offspring (F 1 generation) from a wild population of arctic charr, and the former are also able to maintain growth at higher temperatures. There was a significant difference in maturation between the two populations, as the offspring from cultured fish displayed significantly lower level of maturation: 0%, 4% and 2% mature compared with 24%, 40% and 42% in the offspring from wild fish at temperatures of 12, 14 and 16°C respectively. The offspring from farmed strains of arctic charr thus appear to be the most suitable population for aquaculture.

Impact of environmental factors on the growth and maturation of farmed Arctic charr

“…For most species, the optimum temperature for growth decreases with increasing size of fish (Hallar aker et al 1995;Bj€ ornsson & Tryggvad ottir 1996;Imsland et al 1996Imsland et al , 2001aImsland et al ,b, 2006Imsland et al , 2008Aune et al 1997;Jonassen et al 1999). Long-term studies on the growth of Arctic charr also suggest that the optimum temperature for growth of the fish is reduced as the fish grow larger Siikavuopio et al 2013; Table 1). In Figure 2, we summarize the results of several growth studies of two Icelandic aquaculture populations and one wild population of Arctic charr performed between 1997 and 2000.…”

“…Arctic charr has several features that make it a good species for farming in colder climates. It has relatively good growth rate at low temperatures (Le Franc ßois et al 2002;Siikavuopio et al 2013), it can be reared at high densities Jørgensen et al 1993) and flesh is perceived of high quality (Gines et al 2004;Gunnarsson et al 2012). Several aspects of the farming cycle and the attributes of Arctic charr as food are important to the species sustainability as farmed product.…”

“…Rearing temperature is a highly effective tool to improve growth rate of Arctic charr, and the optimum temperature varies with the size of fish and development (P etursd ottir & Eyþ orsd ottir 1993; Thyrel et al 1999;Jobling et al 2010;Siikavuopio et al 2013). The combination of high temperatures and high growth rate during the juvenile phase can induce early maturation during the on-growing phase so for production of fish >1 kg, moderate (≤10°C) or low temperatures should be applied during the juvenile phase in order to reduce negative effects from maturation.…”

Impacts of environmental matching on the routine metabolic rate and mass of native and mixed-ancestry brook trout (Salvelinus fontinalis) fry

“…We detected significant differences among populations in the mass of fry. Such phenotypic variation has been widely reported in juvenile salmonids, with contributing factors including maternal investment, egg incubation temperature and whether individuals were wild or captive-bred ( Braun et al , 2013 ; Siikavuopio et al , 2013 ). The apparent lack of effect of ancestry suggests that carry-over effects from hatchery conditions likely played a minimal role.…”

Climate warming is predicted to enhance the negative effects of harvesting on high‐latitude lake fish

“…The temperature dependence of K t follows a dome‐shaped curve with a maximum of 0.35 (K max ) at the temperature optimum ( T opt ) of 14.1°C (Larsson & Berglund, , ; Larsson et al, ; Siikavuopio, Foss, Sæther, Gunnarsson, & Imsland, ). The maximum growth rate, K max , is calibrated to the growth of Arctic charr in Lake Takvatn, and individual variability in growth rate is implemented by random sampling from a normal distribution centred on K max .…”