Effects of Early Thermal Environment on Growth, Age at Maturity, and Sexual Size Dimorphism in Arctic Charr

The effects of early thermal environment on growth, age at maturity, and sexual size dimorphism in Arctic charr (Salvelinus alpinus) are investigated. This study is a 654-day long rearing trial split into two sequential experimental phases termed EP1 EP2 lasting 315 339 days, respectively. started the end yolk sac stage when fish were divided three groups reared different target temperatures (7, 10 12 °C). During EP2, all same temperature (7–8 °C) until harvest (~1300 g). Growth rates increased with from 7 to °C, 12C group had 49.0% 19.2% higher mean weight than 7C 10C, Elevated were, however, found cause precocious maturation reduce long-term growth performance. At 3.6% 14.1% 10C 12C, much stronger effect maturity incidence females, while male-biased (SSD) was groups, magnitude SSD positively associated temperature.