SREL Reprint #2129
Relationship of larval density and
hoterozygosity to growth and survival
of juvenile marbled salamanders
(Ambystoma opacum)
Anne C. Chazal, John D. Krenz, and David E. Scott
Abstract:
Intraspecific competition and enzyme variability have been
observed to influence the bioenergetics of many organisms. In
amphibians, larval growth affects body size at metamorphosis,
which in turn can lead to differences in adult survival and
fecundity. We manipulated larval density in a population of the
marbled salamander, Ambystoma opacum, and measured body
size and enzyme variability in surviving newly metamorphosed
juveniles. Crowded larval conditions resulted in lower survival
and smaller body sizes at metamorphosis. Multilocus
heterozygosity showed no relation to body size at high larval
densities; however, at low larval densities relatively homozygous
animals were larger. There was a significant interaction between
heterozygosity and larval density in their effects on larval traits.
Competition had a greater effect on body size at metamorphosis
than did heterozygosity. Survival may be enhanced by
heterozygosity but in a manner unrelated to body size.
SREL Reprint #2129
Chazal, A.C., J.D. Krenz, and D.E. Scott. 1996. Relationship of larval density and heterozygosity to growth and survival of juvenile marbled salamanders (Ambystoma opacum). Canadian Journal of Zoology 74:1122-1129.
