Atlantic salmon growth in strongly food-limited environments: Effects of egg size and paternal phenotype?
S. Einum-2003
Environmental Biology of Fishes, 67(3):
263-268
Abstract:
I manipulated egg size and followed individual mass
trajectories from the egg stage in Atlantic salmon to test for effects of
size, and for interactions between size and paternal body mass, on offspring
performance in strongly food-limited environments. Egg size had a strong
effect on body mass at yolk absorption, causing juveniles originating from
large eggs to outgrow their siblings from small eggs. This corroborates
previous findings of egg size effects under more benign environments, and
demonstrates that positive effects of egg size on offspring success are
manifested even under strong food-limitation. Previously reported negative
effects of being large during the critical period for survival in dense
populations are thus likely related to social interactions, rather than to
effects of density on total food abundance in the environment. The effect of
egg size on offspring performance, and hence the optimal egg size, was
independent of paternal body mass.
(Norwegian
Institute for Nature Research, Tungasletta 2, NO-7485 Trondheim, Norway,
e-mail: sigurd.einum@nina.no)