Berg, O.K., A.P. Hendry, B. Svendsen, C. Bech, J.V. Arnekleiv and A. Lohrmann (2001). Maternal provisioning of offspring and the use of those resources during ontogeny: variation within and between Atlantic salmon families. Funct. Ecol. 15: 13-23..
1. We measured the size and proximate composition of eggs and alevins
(larvae) from six full sibling families of Atlantic salmon (Salmo salar),
at six stages between fertilisation and first feeding.
2. Egg and alevin size measures (diameter, wet mass, dry mass) and
proximate composition attributes (water, protein, fat, energy) were all
highly correlated with each other (r = 0.89-0.99), suggesting that each
is a reasonable surrogate for any other.
3. Most of the variation in egg size (95.0-97.0%) and composition attributes
(95.5-97.9%) was partitioned between, rather than within, females. Most
of this variation was attributable to differences in female size, owing
to the length of time spent at sea.
4. Fat, protein, and energy content varied less on a relative basis
(controlling for egg size variation) than on an absolute basis, suggesting
that certain combinations of egg attributes are optimal regardless of egg
size.
5. Stored fat decreased by 9.6 µg d-1 before hatching
but then by increased by 27.4 µg d-1 after hatching. The
increase after hatching suggests that alevins actively synthesise (probably
from protein) and store lipids between hatching and first feeding.
6. Stored protein decreased by 8.8 µg d-1 before hatching
and by 181.3 µg d-1 after hatching. Assuming all metabolic
energy was derived from stored protein, metabolic rate increased logarithmically
from 0.115 J d-1 to 5.43 J d-1. Rates of oxygen consumption
estimated from protein loss (6.09 – 288.9 µLO2 d-1) were similar
to those reported in studies that measured oxygen consumption using respirometry.
7. Alevins appear to convert protein to fat, a change that their mothers
were unable or unwilling (in an evolutionary sense) to make. This may reflect
the conflicting goals of parents and offspring for maximising fitness.
[Back]