Food availability in spring affects smolting in brown trout (Salmo trutta)

• Prior to out-migration, salmonid fish typically undergo physiological and morphological changes-a process known as smolting. This study indicates that smolting in brown trout (Salmo trutta) is affected by feeding conditions in spring immediately prior to out-migration. This conclusion was reached after experimentally testing the effect of seasonal variation in food availability on smolt status in the spring. A migratory strain of trout was administered either high or low food rations in the autumn, winter, or spring prior to release in the spring. While fish growth or condition could be affected in any season, it was spring rationing that reduced growth and growth-related variables and that caused increased smolting. Our result supports the idea that smoltification and the decision to migrate is affected by spring food availability regardless of conditions in the previous autumn or winter.

Ämnesord

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Nyckelord

JUVENILE ATLANTIC SALMON; PROBABILISTIC REACTION NORMS; LIFE-HISTORY PATTERNS; POPULATION-DENSITY; MIGRATORY BEHAVIOR; EARLY MATURATION; STEELHEAD TROUT; ARCTIC CHARR; SALAR SMOLTS; GROWTH

Biology

Biologi

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