First feeding of Atlantic salmon ( Salmo salar L.) fry as influenced by temperature regime

Atlantic salmon fry grew best during first feeding at temperatures of 16–20°C. Diurnally cycled temperature regimes (20°C day/12°C night or 16°C day/ 12°C night) did not improve initial growth rates as compared with those of fry reared at constant 20°C or 16°C. Incubation temperature prior to swim-up had no effect on growth during initial feeding. Internal yolk remaining in newly feeding fry could be estimated with the formula 0.56 y + 0.825 (1− y) = h; where y=wet weight fraction that is yolk, and h=the water content of the fry. Water content of 80% in swim-up fry is a suitable index of when to start feeding.