Mesomycetozoea

The Mesomycetozoea or DRIP clade are a small group of protists, mostly parasites of fish and other animals. One species, Rhinosporidium seeberi, infects birds and mammals, including humans. They are not particularly distinctive morphologically, appearing in host tissues as enlarged spheres or ovals containing spores, and most were originally classified in various groups of fungi, protozoa, and algae. However, they form a coherent group on molecular trees, closely related to both animals and fungi and so of interest to biologists studying their origins.

The name DRIP is an acronym for the first protozoa identified as members of the group - Dermocystidium, the rosette agent, Ichthyophonus, and Psorospermium. Cavalier-Smith later treated them as the class Ichthyosporea, since they were all parasites of fish. Since other new members have been added, Mendoza et al. suggested changing the name to Mesomycetozoea, which refers to their evolutionary position. Note the name Mesomycetozoa (without a second e) is also used to refer to this group, but Mendoza et al. use it as an alternate name for the phylum Choanozoa.