Emerging diseases

We are examining how bryozoans act as a source of a disease in salmon and trout that is increasing in prevalence and severity as a result of environmental change.

Myxozoans are a group of parasites that live inside the bodies of their hosts. They have a complex life cycle, exploiting both vertebrate and invertebrate hosts. The myxozoan Tetracapsuloides bryosalmonae develops in freshwater bryozoans and causes a devastating disease called Proliferative Kidney Disease (PKD) when transmitted to salmon and trout hosts.

PKD is emerging as a serious disease in wild and farmed fish populations as a result of environmental change. 

We are investigating the drivers of PKD by:
  • characterising bryozoan populations and the dynamics of the myxozoan parasite within this host
  • establishing risk factors associated with disease prevalence, burden in bryozoans and disease transmission to fish

A second project uses molecular tools to sample myxozoan diversity and distribution to determine what other fish diseases may be associated with myxozoans that develop in bryozoans.

A fish infected with PKD

Swollen kidney of fish with PKD.

Project researchers



Myxozoa are endoparasites, meaning they live within their hosts. Myxozoans have a two-host lifestyle, for example developing infectious spores while living in bryozoans, which then disperse and infect fish.

Supported by: