Mesomycetozoea
Encyclopedia
The Mesomycetozoea are a small group of protist
s, mostly parasites of fish and other animals.
s, 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 animal
s and fungi
and so of interest to biologists studying their origins. In a 2008 study they emerge robustly as the sister-group of the clade
Filozoa
, which includes the animals.
later treated them as the class Ichthyosporea, since they were all parasites of fish.
Since other new members have been added (e.g. the former fungal orders Eccrinales
and Amoebidiales), 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
.
Protist
Protists are a diverse group of eukaryotic microorganisms. Historically, protists were treated as the kingdom Protista, which includes mostly unicellular organisms that do not fit into the other kingdoms, but this group is contested in modern taxonomy...
s, mostly parasites of fish and other animals.
Significance
They are not particularly distinctive morphologically, appearing in host tissues as enlarged spheres or ovals containing sporeSpore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
s, 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 animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s and fungi
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
and so of interest to biologists studying their origins. In a 2008 study they emerge robustly as the sister-group of the clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
Filozoa
Filozoa
The Filozoa are a monophyletic grouping within the Opisthokonta. They include animals along with their nearest unicellular relatives ....
, which includes the animals.
Terminology
The name DRIP is an acronym for the first protozoa identified as members of the group, Cavalier-SmithThomas Cavalier-Smith
Professor Thomas Cavalier-Smith , FRS, FRSC, NERC Professorial Fellow, is a Professor of Evolutionary Biology in the Department of Zoology, at the University of Oxford...
later treated them as the class Ichthyosporea, since they were all parasites of fish.
- order DermocystidaDermocystidaDermocystida is a order of parasitic protists.-Genera:* Amphibiocystidium* Amphibiothecum * Dermocystidium* Rhinosporidium* Sphaerothecum...
- "D": DermocystidiumDermocystidiumDermocystidium is a genus of cyst forming parasitic protists of fish, which are the causative agents of dermocystidiosis.- Taxonomic History :...
. One species, Rhinosporidium seeberiRhinosporidium seeberiRhinosporidium seeberi is a eukaryotic pathogen responsible for rhinosporidiosis, a disease which affects humans, horses, dogs, and to a lesser extent cattle, cats, foxes, and birds...
, infects birds and mammals, including humans. - "R": the "rosette agent", now known as Sphaerothecum destruensSphaerothecum destruensSphaerothecum destruens is a parasite of fish. It was first discovered in the United States in association with invasive species including topmouth gudgeon but was found to be the causative agent of a disease in the UK affecting salmonid species such as Atlantic salmon and brown trout...
- "D": Dermocystidium
- order IchthyophonidaIchthyophonidaIchthyophonida is an order of parasitic protists.-Taxonomy:Members of Ichthyophonida include* Abeoforma whisleri* Amoebidiidae** Amoebidium** Paramoebidium* Anurofeca richardsii* Caullerya mesnili* Creolimax fragantissima...
- "I": IchthyophonusIchthyophonusIchthyophonus is a genus of unicellular parasites of fish....
- "P": Psorospermium
- "I": Ichthyophonus
Since other new members have been added (e.g. the former fungal orders Eccrinales
Eccrinales
Eccrinales are an order of protists, previously thought to be zycomycete fungi belonging to the class Trichomycetes, but now considered to be members of the opisthokont protist group Mesomycetozoea.- Taxonomy :* Order: Eccrinales** Family: Eccrinaceae...
and Amoebidiales), 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
Opisthokont
The opisthokonts or "Fungi/Metazoa group" are a broad group of eukaryotes, including both the animal and fungus kingdoms, together with the eukaryotic microorganisms that are sometimes grouped in the paraphyletic phylum Choanozoa...
.