What is Whirling Disease?
Myxobolus cerebralis is a parasite of salmonids (salmon, trout) that causes whirling disease in farmed salmon and trout and also in wild fish populations. It was first described from rainbow trout in Germany a century ago, but its range has spread and it has appeared in most of Europe, the United States, South Africa and other countries.
Whirling disease afflicts juvenile fish and causes skeletal deformation and neurological damage. Fish "whirl" rather than swim forward, find feeding difficult, and are more vulnerable to predators. The mortality rate is high for fingerlings, up to 90% of infected populations, and those that do survive are deformed by the parasite residing in their cartilage and bone. They act as a reservoir for the parasite, which is released into water following the fish's death. M. cerebralis is one of the most economically important myxozoans in fish as well as one of the most pathogenic. It was the first myxosporean whose pathology and symptoms were described scientifically. The parasite is not transmissible to humans.
March 2, 2007 6:49 AM | Category: Fish