Yolk Absorption, Yolk Sac Constrictions, Mortality, and Growth During First Feeding of Atlantic Salmon (Salmo salar) Incubated on Astro-turf

Abstract

Groups of pooled Atlantic salmon (Salmo salar) eggs were incubated in a "California" incubation system with and without astro-turf, an artificial substrate, and later transferred to separate feeding units. Alevins reared in astro-turf absorbed their yolk sac faster and more efficiently than alevins reared on a flat screen. Alevins reared on the flat screen developed yolk sac constrictions probably due to the backward and lateral force created by the high swimming activity. No such malformations were found on the yolk sacs of the astro-turf reared alevins. The fry hatched without astro-turf grew faster than the fry hatched with astro-turf during the initial feeding period, but later this was reversed. Mortality of alevins and fry hatched with astro-turf was lower during incubation and during first feeding.