Influence of the timing of initial feeding on the survival and growth of hatchery-reared Atlantic salmon ( Salmo salar L.)

Abstract

This study investigated the effects of timing of initial feeding on growth and survival of Atlantic salmon ( Salmo salar L.) fry. Food was first presented to triplicate groups of 200 salmon fry at four different stages in development (375, 548, 653, 800 degree-days post-hatching). Alevins fed prior to final yolk resorption were significantly larger and had lower mortalities than those fed after the stage at which the maximum alevin wet weight (MAWW) was achieved (circa 435 degree-days post-hatching). Although the “window” of initial feeding opportunity lasted several weeks, delaying feeding much beyond MAWW reduced absolute growth. A 5-week delay led to mortalities which approached 60%. However, initial feeding can be delayed 1–2 weeks at 10°C without adversely affecting subsequent survival or specific growth rate.