Myxosoma cerebralis

Myxosoma cerebralis is a protozoan parasite that causes whirling disease, an infectious and often fatal illness primarily affecting young salmonid fish like trout and salmon. This disease is characterized by skeletal deformities and a distinctive swimming pattern where affected fish circle or swim in a spiral.1

Myxosporidians, including Myxosoma cerebralis, are parasites known for their complex spores. These spores contain an infective amoeboid sporoplasm and specialized polar capsules. While primarily infecting fish, they can also impact amphibians and reptiles. The infection cycle begins when an animal ingests the spores, leading to the release of the sporoplasm, which then develops and produces new spores within the host.2