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Holozoa
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 (or animals) 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. The holozoan protists play a crucial role in understanding the evolutionary steps leading to the emergence of multicellular animals from single-celled ancestors. Recent genomic studies have shed light on the evolutionary relationships between the various holozoan lineages, revealin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syssomonas
''Syssomonas'' is a monotypic genus of unicellular flagellated protists containing the species ''Syssomonas multiformis''. It is a member of Pluriformea inside the lineage of Holozoa, a clade containing animals and their closest protistan relatives. It lives in freshwater habitats. It has a complex life cycle that includes unicellular amoeboid and flagellated phases, as well as multicellular aggregates, depending on the growth medium and nutritional state. Life stages ''Syssomonas multiformis'' is a species of unicellular protists with naked cells (lacking any Test (biology), shell or scales) that presents with a variety of life forms during their complex Biological life cycle, life cycle. These forms include: round flagellate cells (7–14 μm in diameter) with one posterior (anatomy), posterior flagellum, amoeboflagellate (i.e. with both flagella and pseudopodia) cells, amoeboid non-flagellar cells, and spherical microbial cyst, cysts. They can also form clusters of multiple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filozoa
The Filozoa are a monophyletic grouping within the Opisthokonta. They include animals and their nearest unicellular relatives (organisms which are more closely related to animals than to fungi or Mesomycetozoa). Three groups are currently included within the clade Filozoa: * Group Filasterea - recently described to include the genera '' Ministeria'' and '' Capsaspora'' * Group Choanoflagellatea - collared flagellates * Kingdom Animalia - the group of which all extant animals belong to Etymology The name Filozoa originates from the Latin word ''filum'' meaning "thread" and the Greek word ''zōion'' meaning "animal". Phylogeny Below is a phylogenetic tree of Filozoa and the groups most closely related to the Filozoa : Characteristics The ancestral opisthokont cell is assumed to have possessed slender filose (thread-like) projections or 'tentacles'. In some opisthokonts (Mesomycetozoa and '' Corallochytrium'') these were lost. They are retained in Filozoa, where they are sim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pluriformea
Pluriformea is a proposed sibling clade of the Filozoa, and consists of '' Syssomonas multiformis'' and the Corallochytrea. Together with the Ichthyosporea The Ichthyosporea (or DRIP clade, or Mesomycetozoea) are a small group of Opisthokonta in Eukaryota (formerly protists), mostly parasites of fish and other animals. Significance They are not particularly distinctive morphologically, appearing i ... and the Filozoa, they form the Holozoa. An up to date cladogram is The alternative hypothesis is the Teretosporea clade. References {{Taxonbar, from=Q55630147 Holozoa Opisthokont classes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunicaraptor
''Tunicaraptor'' is a genus of marine microbial protists containing the single species ''Tunicaraptor unikontum'', discovered in 2020 from marine waters of Chile. It is a lineage of predatorial flagellates closely related to animals. It has a rare feeding structure not seen in other opisthokonts. Morphology ''Tunicaraptor unikontum'' is a small unicellular flagellate composed of oval cells similar to some fungal zoospores, with a length of 3–5 μm. It has one flagellum with a flagellar pocket, and an external envelope or ‘theca’ with long hairs of around 110 nm. Unlike other unicellular opisthokonts, ''Tunicaraptor'' cells possess a ‘mouth’, a specialized feeding structure in the anterior part of the cell. There are two centrioles: one develops a flagellum and the other rotates to the kinetosome. The mitochondrial cristae are flat and associated with lipid globules. Discovery and etymology ''Tunicaraptor unikontum'' was isolated from marine waters of the coast of Chil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filasterea
Filasterea is a proposed basal Filozoan clade of single-celled ameboid eukaryotes 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 78 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. Etymology From Latin ''filum'' meaning "thread" and Greek ''aster'' meaning "star", it indicates the main morphological features shared by all their integrants: small, rounded amoeboids with a mononucleated cellular body, covered in long and radiating cell protrusions known as filopodia. These filopodia may be involved in substrate adhesion and capture of prey. Applications There are currently cultures from two filasterean species: ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choanozoa
Choanozoa is a clade of opisthokont eukaryotes consisting of the choanoflagellates (Choanoflagellatea) and the animals (Animalia, Metazoa). The sister-group relationship between the choanoflagellates and animals has important implications for the origin of the animals. The clade was identified in 2015 by Graham Budd and Sören Jensen, who used the name Apoikozoa. The 2018 revision of the classification first proposed by the International Society of Protistologists in 2012 recommends the use of the name Choanozoa. Introduction A close relationship between choanoflagellates and animals has long been recognised, dating back at least to the 1840s. A particularly striking and famous similarity between the single-celled choanoflagellates and multicellular animals is provided by the collar cells of sponges and the overall morphology of the choanoflagellate cell. The relationship has since been confirmed by multiple molecular analyses. This proposed homology was however thrown into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protist
A protist ( ) or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists do not form a natural group, or clade, but are a paraphyletic grouping of all descendants of the last eukaryotic common ancestor excluding land plants, animals, and fungi. Protists were historically regarded as a separate taxonomic kingdom known as Protista or Protoctista. With the advent of phylogenetic analysis and electron microscopy studies, the use of Protista as a formal taxon was gradually abandoned. In modern classifications, protists are spread across several eukaryotic clades called supergroups, such as Archaeplastida ( photoautotrophs that includes land plants), SAR, Obazoa (which includes fungi and animals), Amoebozoa and " Excavata". Protists represent an extremely large genetic and ecological diversity in all environments, including extreme habitats. Their diversity, larger than for all other eukaryotes, has only been discovered in rece ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salpingoeca
''Salpingoeca'' is a genus of Choanoflagellate Choanoflagellates are a group of free-living unicellular and colonial flagellate eukaryotes considered to be the closest living relatives of animals. The name refers to the characteristic funnel-shaped "collar" of interconnected microvilli and ...s in the family Salpingoecidae. References * Ultrastructure et mode de nutrition du Choanoflagellé Salpingoeca pelagica, sp. nov. comparaison avec les choanocytes des Spongiaires. M Laval, 1971 * Cell differentiation and morphogenesis in the colony-forming choanoflagellate Salpingoeca rosetta. MJ Dayel, RA Alegado, SR Fairclough, TC Levin... - Developmental biology, 2011 * Premetazoan genome evolution and the regulation of cell differentiation in the choanoflagellate Salpingoeca rosetta SR Fairclough, Z Chen, E Kramer, Q Zeng, S Young... - Genome biology, 2013 External links * * Choanoflagellate genera Eukaryote genera Opisthokont genera {{Holozoa-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corallochytrium
''Corallochytrium'' belongs to the class of Corallochytrea. It is either a sister group to Ichthyosporea together forming Teretosporea, or a sister group to '' Syssomonas'' together forming Pluriformea. ''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 (C-14 reductase and α-AAR respectively). Etymology The genus name is derived from the habitat in which it was first found: coral reef lagoons. The single species name is derived from the limax-shaped (slug- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicellum Brasieri
''Bicellum'' is a genus of fossil holozoans containing the single species ''Bicellum brasieri''. It is one billion years old and could be the oldest example of complex multicellularity in the evolutionary lineage leading to the animals, and has been described as bridging "the gap between the very first living creatures — single-celled organisms — and more complex multicellular life." It was discovered in 2021, and is posthumously named after the late Martin Brasier, a paleontologist who was a co-author of the paper that first described it. Fossil site ''Bicellum'' was found in sediments from the Diabaig Formation in Loch Torridon, Scotland. The Diabaig Formation, considered to represent an ancient lake deposit, was already known to preserve the first non-marine eukaryote The eukaryotes ( ) constitute the Domain (biology), domain of Eukaryota or Eukarya, organisms whose Cell (biology), cells have a membrane-bound cell nucleus, nucleus. All animals, plants, Fungus, fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metazoa
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia (). With few exceptions, animals consume organic material, breathe oxygen, have myocytes and are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. Animals form a clade, meaning that they arose from a single common ancestor. Over 1.5 million living animal species have been described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from to . They have complex ecologies and interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology, and the study of animal behaviour is known as ethology. The animal kingdom is divided into five major clades, namely Porifera, Ctenophora, Placozoa, C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Craspedida
Craspedida is an order of choanoflagellate Choanoflagellates are a group of free-living unicellular and colonial flagellate eukaryotes considered to be the closest living relatives of animals. The name refers to the characteristic funnel-shaped "collar" of interconnected microvilli and ..., with members with an exclusively organic covering. Crown group craspedids (and perhaps crown group choanoflagellates if Acanthoecida arose within Craspedida) appeared 422.78 million years ago. Although a previous study from 2017 recovered the divergence of the crown group choanoflagellates (craspedids) at 786.62 million years. Craspedid genera ''Codonosiga'' ''Proterospongia'' ''Salpingoeca'' '' Salpingoeca rosetta'' has been named for the rosette-shaped colonies formed by its cells. Recent studies show a bacterial sulfonolipid, called rosette inducing factor (RIF-1) produced by '' Algoriphagus machipongonensis'' triggers colony formation in ''S. rosetta''. References * Extende ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
