Micro jellyfish-like parasites are reclassified after leaving biologists’ baffled by the parasites origin and their classification until recently.
Classifying organisms, be they unicellular or multicellular isn’t an easy task. However, with the reclassification of the parasites known as myxozoans scientists are surprised that for so long the jellyfish-like parasites have been known as protists.
Myxozoans are microscopic organisms infecting marine vertebrates and invertebrates as well. Until recently it was thought that they are unicellular parasitic organisms. However, after performing genome sequencing on the Myxozoan DNA, researchers with the University of Kansas discovered that these microscopic jellyfish-like parasites may be small, but they grow to multiple cells throughout their lifetime.
Not only this, but they are in fact part of the Cnidaria family, closely related to corals and jellyfish. In their evolution, Myxozoans lost their mouths or guts or the ability to survive independent of a host.
Moreover, they lost a great deal of genes in the evolutionary process. According to the study published in the Proceedings of the National Academy of Sciences, Myxozoans genomes are 20 to 40 times more reduced than those of jellyfish.
In what the authors call an evolutionary cleanse, the microscopic parasites have become smaller jellyfish-like organism with a complex structure nonetheless. Micro jellyfish-like parasites are reclassified after a microscopic analysis in addition to genome sequencing showed that Myxozoans still retain one key feature reminiscent of their jellyfish origin: the nematocyst or stinging cells of the marine creatures.
Myxozoans only measure approximately 20 microns at the largest. Due to their tiny sizes biologists believed that they are unicellular organisms. These complex microscopic jellyfish-like parasites find a perfect host in fish.
While the majority don’t affect their hosts, some do cause problems to aquaculturists breeding fish for human consumption. One disease caused by Myxozoans is known as Whirling disease. Fish’s neurological system is affected, causing them to swim in a spiral pattern at all times. Another disease affect the muscle tissue, rendering it watery and soft and certainly undesirable for human consumption.
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