The cure for the exotic whirling disease, a
fatal malady in trout, could - ironically - lie in a foreign fish.
Researchers recently found that Hofer rainbow trout, the offspring
of Pacific rainbow trout taken to Germany in 1880, are 10 to 100
times less susceptible to whirling disease than native U.S. rainbow
trout, thanks to a lengthy exposure to and co-evolution with the
parasite in Europe. The finding could be a major breakthrough.
Since whirling disease first infected American trout in 1957, it
has devastated the Rocky Mountains' $2 billion fishing industry
(HCN, 9/18/95: The West's fisheries spin out of
"It provides us with hope," says Ronald
Hendrick, an epidemiologist at the University of California at
Davis. "The Hofer rainbow trout offer us a valuable insight into
the mechanisms of resistance, with very encouraging results."
Hendrick hopes to use the Hofer to create a genetically resistant
Fish and wildlife managers,
however, have concerns about introducing imported Hofer trout into
American waters. "We don't know if they are capable of surviving as
wild fish," says Colorado Division of Wildlife senior fish
pathologist Peter Walker. He's also concerned that Hofer trout
could displace native fish, and introduce foreign
Before states can import the fish,
though, the U.S. Fish and Wildlife Service has to grant its
approval * and that could take years.