Myxozoa

Myxozoa are a group of parasitic microorganisms that are related to cnidarians. They are microscopic and have complex life cycles. They are known to infect fish, annelids, and bryozoans.

Taxonomy

Myxozoa was originally classified as a protozoan but later reclassified as a cnidarian due to its similar genetic and morphological characteristics. The group contains over 1300 species, divided into two orders: Myxosporea and Malacosporea.

Morphology

Myxozoa are microscopic and have a complex structure. They consist of a single cell surrounded by a protective shell, with two types of spores: myxospores and actinospores. Myxospores are produced in the host's tissues, while actinospores are produced in the alternate host.

Life Cycle

The life cycle of Myxozoa involves two hosts. The primary host is usually a fish, where the parasite forms myxospores. These spores are released into the water and ingested by the secondary host, usually an annelid or bryozoan. In the secondary host, the spores transform into actinospores, which are released back into the water to infect new fish hosts.

Pathology

Myxozoa can cause a variety of diseases in fish, including myxobolus cerebralis, which causes whirling disease in trout. They can also cause significant economic losses in aquaculture.

Treatment and Control

Treatment of Myxozoa infections is difficult due to the complex life cycle of the parasite. Control measures include good hygiene practices in aquaculture and the use of drugs such as praziquantel.

See Also

• Cnidaria
• Parasite
• Aquaculture

Myxozoa

• 
  Fdl17-9-grey