Myxozoans: The Microscopic, Parasitic...Jellyfish.

By Nathan Campos

When it comes to creatures of the deep blue sea, jellyfish (Cnidarians) have probably never been held in high regards by any species of animal.  According to new research by the University of Kansas, jellyfish are about to be much more hated.  Gene-sequencing conducted by the researchers on myxozoans, microscopic parasites that are capable of infecting both vertebrates and invertebrates, uncovered that the organisms are actually a form of “highly reduced” Cnidarians.  Comprised of only a few cells measuring 10 to 20 microns each, myxozoans have one of the smallest animal genomes on record.  While an average Cnidarian has over 300 million base pairs, myxozoans have approximately 20 million base pairs.  While myxozoans are a microscopic, extremely biodegraded species of macroscopic jellyfish, they still retained the nematocyst (stinger) of a jellyfish, along with the genes required to produce it.  Oddly enough, a group of genes that are vital in animal development, Hox genes, are absent from their genome.  The findings of the study may prove to be valuable in the commercial fishing industry- myxozoans infect fish and disrupt the aquaculture of commercial fishing spots.  With a better genetic understanding of myxozoans, the possibilities of finding solutions to infection outbreaks are highly increased.   

(Credit: Left Photo: A. Diamant.  Right Photo: P. Cartwright)  The images above are a visual comparison of myxozoans (Kudoa iwatai, left photo) and a full-sized jellyfish (Aurelia aurita, right photo).

E. Sally Chang, et al. Genomic insights into the evolutionary origin of Myxozoa within Cnidaria. PNAS, November 16, 2015 DOI: 10.1073/pnas.1511468112