Travel Reference
In-Depth Information
he tapeworm
(Diphyllobothrium
sp. in larval stage) is a parasite that has been found here
since before Yellowstone was a park. It is passed back and forth between the mammals and
birds on land and the fish and crustaceans in water. Fortunately, tapeworms are harmless
to man after the fish is cooked, although finding worms is unaesthetic. For reasons not yet
understood, fish from Yellowstone Lake were found to have fewer tapeworms in the years
after the 1988 fires. The large older cutthroat are the most likely to be infected, but no one
is allowed to keep these according to present regulations.
Whirling disease is a relatively recent development. It's caused by a parasite
(Myxobolus
cerebralis)
in another type of worm (the
Tubifex
worm) eaten by trout. Early this century
biologists found the parasite in up to 20 percent of the lake's cutthroat trout and in 90 per-
cent of Pelican Creek's, leading to closure of fishing in that creek. But in 2012 Yellowstone's
supervisory fisheries biologist Todd Koel reported that all tested creeks other than Pelican
Creek were free of whirling disease.
The New Zealand mud snail
(Potamopyrgus antipodarum)
reproduces so fast that it
occupies habitat at an alarming rate. It can reach a density of 30,000 per square foot and
could conceivably become a problem to the fish. It has been found in the Madison, lower
Gibbon, Lewis, and Firehole Rivers, and near Gardiner.
