The opisthokonts are a broad group of eukaryotes, including both the animal and fungus kingdoms. The opisthokonts, previously called the "Fungi/Metazoa group", are generally recognized as a clade. Opisthokonts together with Apusomonadida and Breviata comprise the larger clade Obazoa.
The Ichthyosporea are a small group of Opisthokonta in Eukaryota, mostly parasites of fish and other animals.
The Laboulbeniomycetes are a unique group of fungi that are obligatorily associated with arthropods, either as external parasites or for dispersal (Pyxidiophorales).
The Laboulbeniales is an order of Fungi within the class Laboulbeniomycetes. They are also known by the colloquial name beetle hangers or labouls. The order includes around 2,325 species of obligate insect ectoparasites that produce cellular thalli from two-celled ascospores. Of the described Laboulbeniales, Weir and Hammond 1997 find 80% to be from Coleoptera and the next largest group to be the 10% from Diptera. Recently, the genus Herpomyces, traditionally considered a basal member of Laboulbeniales, was transferred to the order Herpomycetales based on molecular phylogenetic data. Laboulbeniales typically do not kill their hosts, although they may impair host fitness if the parasite density is high.
Epichloë is a genus of ascomycete fungi forming an endophytic symbiosis with grasses. Grass choke disease is a symptom in grasses induced by some Epichloë species, which form spore-bearing mats (stromata) on tillers and suppress the development of their host plant's inflorescence. For most of their life cycle however, Epichloë grow in the intercellular space of stems, leaves, inflorescences, and seeds of the grass plant without incurring symptoms of disease. In fact, they provide several benefits to their host, including the production of different herbivore-deterring alkaloids, increased stress resistance, and growth promotion.
The Pleosporales is the largest order in the fungal class Dothideomycetes. By a 2008 estimate, it contained 23 families, 332 genera and more than 4700 species. The majority of species are saprobes on decaying plant material in fresh water, marine, or terrestrial environments, but several species are also associated with living plants as parasites, epiphytes or endophytes. The best studied species cause plant diseases on important agricultural crops e.g. Cochliobolus heterostrophus, causing southern corn leaf blight on maize, Phaeosphaeria nodorum causing glume blotch on wheat and Leptosphaeria maculans causing a stem canker on cabbage crops (Brassica). Some species of Pleosporales occur on animal dung, and a small number occur as lichens and rock-inhabiting fungi.
The Zoopagomycotina are a subdivision of the fungal division Zygomycota sensu lato. It contains 5 families and 20 genera. Relationships among and within subphyla of Zygomycota are poorly understood, and their monophyly remains in question, so they are sometimes referred to by the informal name zygomycetes.
The Harpellales are an order of fungi classified in the subdivision Kickxellomycotina. Thalli are either unbranched or branched, producing basipetal series of trichospores. Zygospores are biconical. Species in the order are found attached to the gut lining of aquatic larvae of Insecta or (rarely) Isopoda. Harpellales are divided into two families, the Harpellaceae and the Legeriomycetaceae. According to the Dictionary of the Fungi, the order contains 38 genera and 200 species. The order was formally described in 1978 Mycotaxon publication. Harpellales has served as a model to study and understand the evolution, growth, and biodiversity of other such fungi found in the gut as species are plentiful around the world.
Corallochytrium belongs to the class of Corallochytrea within Teretosporea and is a sister group to Ichthyosporea. Corallochytrium limacisporum is the only species of Corallochytrium known so far. It was first discovered and named in the Arabian Sea’s coral lagoons by Kaghu-Kumar in 1987. It was first thought to be a member of the fungi-like thraustochytrids, however, this was later disproven due to Corallochytriums lack of cilia and sagenogenetosome. Little research has been done on the life cycle or morphology. Most research concerning this genus has been done to uncover the evolution of animals and fungi, as Corallochytrium possess both animal and fungal enzymatic trademarks.
Ichthyophonida is an order of parasitic eukaryotes.
Dermocystida is an order of parasitic eukaryotes.
Filasterea is a proposed basal Filozoan clade that includes Ministeria and Capsaspora. It is a sister clade to the Choanozoa in which the Choanoflagellatea and Animals appeared. Originally proposed by Shalchian-Tabrizi et al. in 2008, based on a phylogenomic analysis with dozens of genes. Filasterea was found to be the sister-group to the clade composed of Metazoa and Choanoflagellata within the Opisthokonta, a finding that has been further corroborated with additional, more taxon-rich, phylogenetic analyses.
Holozoa is a clade of organisms that includes animals and their closest single-celled relatives, but excludes fungi and all other organisms. Together they amount to more than 1.5 million species of purely heterotrophic organisms, including around 300 unicellular species. It consists of various subgroups, namely Metazoa and the protists Choanoflagellata, Filasterea, Pluriformea and Ichthyosporea. Along with fungi and some other groups, Holozoa is part of the Opisthokonta, a supergroup of eukaryotes. Choanofila was previously used as the name for a group similar in composition to Holozoa, but its usage is discouraged now because it excludes animals and is therefore paraphyletic.
Eccrinales are an order of eukaryotes, previously thought to be zygomycete fungi belonging to the class Trichomycetes, but now considered to be members of the opisthokont group Mesomycetozoea.
Amoebidiidae is a family of single-celled eukaryotes, previously thought to be zygomycete fungi belonging to the class Trichomycetes, but molecular phylogenetic analyses place the family with the opisthokont group Mesomycetozoea. The family was originally called Amoebidiaceae, and considered the sole family of the fungal order Amoebidiales that included two genera: Amoebidium and Paramoebidium. However, Amoebidiidae is now monogeneric as it was recently emended to include only Amoebidium. Species of Amoebidium are considered obligate symbionts of freshwater-dwelling arthropod hosts such as midge larvae and water fleas (Daphnia). However, because Amoebidium species attach to the exoskeleton (exterior) of the host and grow in axenic culture, at least some species may be facultative symbionts.
Robert W. Lichtwardt was a Brazilian-born American mycologist specializing in the study of arthropod-associated, gut-dwelling fungi (trichomycetes). He is known for his online monograph and interactive keys to trichomycete taxa.
Amoebidium is a genus of unicellular, symbiotic eukaryotes in the Opisthokont group Mesomycetozoea, family Amoebidiidae. Amoebidium species attach to the exoskeleton of freshwater aquatic arthropods such as midge larvae and water fleas (Daphnia). The type species is Amoebidium parasiticum, which is also one of the only species to be cultured axenically.
Paramoebidium is a genus of unicellular, symbiotic eukaryotes that inhabit the digestive tract of immature freshwater arthropod hosts. Paramoebidium is classified in the opisthokont class Mesomycetozoea, and is the sole genus in the family Paramoebidiidae. Prior to 2005, Paramoebidium species were tentatively placed with the fungal group Trichomycetes due to their habitation of arthropod guts, host overlap between various Paramoebidium and fungal trichomycete taxa, and similar vegetative growth form.
Abeoforma whisleri is a single-celled eukaryote that belongs to the Ichthyosporea clade, a group of protists closely related to animals.
Pirum gemmata is a unicellular eukaryote that belongs to the Ichthyosporea clade, a group of protists closely related to animals. P. gemmata was isolated from the gut contents of a marine invertebrate, specifically the detritivorous peanut worm Phascolosoma agassizii.
