Spring 2018

Q) Why is FWP calling Prolific Kidney Disease now PKX?
A) PKD is proliferative kidney disease; PKX is an old term for the parasite
causing PKD. For a long time, it was clear that another species was involved
in the life cycle, but no one could discover what it was. The “X” represented
the unknown species. Now that bryozoans are known to be the final hosts the
expression “PKX” has fallen out of use.
Q) Can anglers do anything to help stop the spread of bryozoans from one river to
another?
A) It is always a good precaution to hose off boots and other equipment
before entering a new fishing site. Live bryozoan fragments or statoblasts
can adhere to fishing gear, especially in standing water. The statoblasts remain
viable even after being dried or frozen for months.
Q) FWP stated in early media reports and also at the meeting held in Livingston
after the Yellowstone River-closure, that they “had only located both the bryozoan
and PKD parasite in two isolated locations in the past 20 years, Cherry Creek and
an irrigation ditch (neither related to a fish-kill)”; yet in your paper on the subject:
Bryozoans as hosts for Tetracapsula bryosalmonae, the PKX organism it was
recorded as present in Ennis Lake and the Lower Madison in 2000.
How did you come to find both the same bryozoan and PKD parasite in this
region and for whom were you doing research at the time (or from where was that
information gathered)?
A) From various sources we compiled a list of sites where PKD had been
reported. The goal of this study was to find out what bryozoan species occur
in the same vicinities. The species we found were well known across the
northern states. This work was funded by the Natural Environment Research
Center in the UK.
MONTANA FLYFISHING