Puzzling piscine sex reversals have left salmon
researchers scratching their heads. A study released by the
University of Idaho and Washington State University reported that
of the female salmon sampled, 84 percent tested positive for a male
genetic marker, suggesting that these females actually began life
as males.
Sex reversals could hold clues to
declining salmon numbers, says James Negler, University of Idaho
zoologist and co-author of the study. Negler says environmental
contaminants may simulate hormones and induce sex reversals, or
that changes in water temperature could be a cause, but more
research is needed before definitive conclusions can be drawn. If
this condition persists, the offspring of sex-reversed salmon could
hold an aberrant YY genotype and breed only males, leading to a
skewed male-to-female ratio in the salmon
population.
Pat Ford of Save Our Wild Salmon
finds it “worrisome” that this discovery materialized in what is
considered to be the healthiest population of wild salmon in the
Northwest. “From the point of view of salmon advocates, it’s not a
good thing,” says Ford. “It seems to be another confirmation that
we’ve got a sick river.”
Read more about this
study online at
uidaho.edu/salmon.
This article appeared in the print edition of the magazine with the headline Sex-swappin’ salmon.
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