Time to adjust to a new feeding environment determines survival and growth of wild-caught white-spotted charr (Salvelinus leucomaenis pluvius)

Abstract

Hatcheries and breeding programs use wild-caught fish reared on artificial diets. Understanding how fish adjust to a new feeding environment in this context might contribute to improving survival and growth outcomes under artificial conditions. In this study, we examined the growth and survival of wild white-spotted charr (Salvelinus leucomaenis pluvius) on a diet of commercial pellets in an artificial rearing environment. Our results revealed that pre-study fork length has a significant influence on pellet consumption, and thereby survival. The primary factor contributing to growth was the number of days until an initial increase in body weight. Post-mortem examination of deceased fish and their condition indicated that in all cases, the most likely cause of death was starvation. These results accordingly indicate that starvation tolerance and the ability to adjust to a new feeding environment are key factors in the survival of wild charr, whereas the time taken to acclimate is a key factor contributing to growth.