mesomycetozoea mesomycetozoea the mesomycetozoea (or drip clade, or ichthyosporea) are a small group of opisthokonta in eukaryota (formerly protists), mostly parasites of fish and other animals. mesomycetozoea sphaeroforma arctica scientific classification domain: eukaryota clade: amorphea clade: obazoa (unranked): opisthokonta (unranked): incertae sedis class: mesomycetozoeamendoza et al. 2002 orders dermocystida ichthyophonida synonyms ichthyosporea cavalier-smith 1998 significance 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 as fungi, protozoa, or colorless 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. in a 2008 study they emerge robustly as the sibling-group of the clade filozoa, which includes the animals. huldtgren et al., following x-ray tomography of microfossils of the ediacaran doushantuo formation, has interpreted them as mesomycetozoan spore capsules. terminology the name drip is an acronym for the first protozoa identified as members of the group, cavalier-smith later treated them as the class ichthyosporea, since they were all parasites of fish. order dermocystida "d": dermocystidium. one species, rhinosporidium seeberi, infects birds and mammals, including humans. "r": the "rosette agent", now known as sphaerothecum destruens order ichthyophonida "i": ichthyophonus "p": psorospermium 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. on eukaryota tree, in opisthokont clade, mesomycetozoea is in the middle ("meso-") of the fungi ("-myceto-") and the animals ("-zoea"). note the name mesomycetozoa (without a third e) is also used to refer to this group, but mendoza et al. use it as an alternate name for basal opisthokonts. phylogeny eukaryota tree. note "ichthyosporea" at bottom left, in opisthokont clade. "metazoa" are animals, and choanoflagellates are closely aligned. fungi is at other end of opisthokont clade, with cristidiscoidea closely aligned. ichthyosporea is in the middle ("meso-") of the fungi ("-myceto-") and the animals ("-zoea"). ichthyosporea dermocystida rhinosporidiaceae sphaerothecum dermocystidium valentines rhinosporidium amphibiocystidium dermotheca dermosporidium ichthyophonida creolimacidae anurofeca creolimax sphaeroforma psorospermidae psorospermis piridae abeoforma caullerya pirum trichomycina amoebidiidae amoebidium ichthyophonidae ichthyophonus paramoebidiidae paramoebidium eccrinida parataeniellaceae parataeniella eccrinaceae eccrinidus enterobryus leidyomyces enteromyces arundinula enteropogon taeniella taeniellopsis astreptonema palavascia taxonomy class ichthyosporea cavalier-smith 1998 order dermocystida cavalier-smith 1998 family rhinosporidiaceae mendoza et al. 2001 genus amphibiocystidium pascolini et al. 2003 genus chromosphaera grau-bové et al. 2017 genus dermocystidium pérez 1908 genus dermosporidium carini 1940 genus dermotheca genus rhinosporidium minchin & fantham 1905 genus sphaerothecum arkush et al. 2003 (rosette agent) genus valentines borteiro et al. 2018 order ichthyophonida cavalier-smith 1998 suborder sphaeroformina cavalier-smith 2012 family creolimacidae cavalier-smith 2012 genus anurofeca baker, beebee & ragan 1999 genus creolimax marschall et al. 2008 genus sphaeroforma jostensen et al. 2002 family psorospermidae cavalier-smith 2012 genus psorospermis cavalier-smith 2012 family piridae cavalier-smith 2012 genus caullerya chatton 1907 genus abeoforma marshall & berbee 2011 genus pirum marshall & berbee 2011 suborder trichomycina cavalier-smith 2012 genus †paleocadus poinar 2016 family amoebidiidae lichtenstein 1917 ex kirk et al. 2001 genus amoebidium cienkowski 1861 family ichthyophonidae cavalier-smith 2012 genus ichthyophonus plehn & mulsow 1911 family paramoebidiidae reynolds et al. 2017 genus paramoebidium léger & duboscq 1929 family parataeniellaceae manier & lichtward 1968 genus lajassiella tuzet & manier 1951 ex manier 1968 genus nodocrinella scheer 1977 genus parataeniella poiss. 1929 family eccrinaceae leger & duboscq 1929 genus alacrinella manier & ormières ex manier 1968 genus arundinula léger & duboscq 1906 genus astreptonema hauptfleisch 1895 genus eccrinidus manier 1970 genus eccrinoides léger & duboscq 1929 genus enterobryus genus enteromyces lichtwardt 1961 genus enteropogon hibbits 1979 non nees 1836 genus leidyomyces lichtwardt et al. 1999 genus palavascia tuzet & manier 1947 ex lichtwardt 1964 genus paramacrinella manier & grizel 1971 genus passalomyces lichtwardt et al. 1999 genus ramacrinella manier & ormiéres 1962 ex manier 1968 genus taeniella léger & duboscq 1911 genus taeniellopsis poisson 1927