cage densities due to differential larval/postlarval survival and initial
postlarval stocking numbers) may have influenced shrimp weights at
this first measure. If this was the case, the absence of correlation could
be explained by a dissipation of these effects at the later measures
(week 32/44). As shrimp weight increased approx. 10-fold (on
average) from week 16 to week 32/44, it seems plausible that any
effects of early life rearing, if present, may have dissipated by these
later measures. Another possible explanation for the absence of
genetic correlation between week 16 and later ages is genotype-byage
interaction. A prior study evaluating size of P. vannamei families at
different ages found no significant phenotypic correlation between
harvest and broodstock weights (Argue et al., 2000); suggestive of
genotype-by-age interaction. The authors proposed that growth in P.
vannamei may have a different genetic basis pre- and post-harvest
(Argue et al., 2000); presumably due to inter-family variation in the
effects of reproductive maturation on growth between harvest and
broodstock age. Notably, the present study was not able to determine
the reason for the absence of correlation between weight at week 16
and week 32/44; and plausibly, both early life rea