iTrichoplax adhaerens
Scientific classification
Kingdom: Animalia Phylum: Placozoa Grell, 1971 Class: Trichoplacoidea Order: Trichoplacida Family: Trichoplacidae Genus: Trichoplax Species: T. adhaerens
Binomial name
Trichoplax adhaerens F.E. von Schultze, 1883

Trichoplax adhaerens is a simple balloon-like marine animal with a body cavity filled with pressurized fluid. It is given its own phylum, called Placozoa; the only other species, Treptoplax reptans, was described in 1896 and has not been seen since, leading to doubts about its existence. Image File history File linksMetadata Trichoplax_mic. ... For other uses, see Scientific classification (disambiguation). ... Phyla Subregnum Parazoa Porifera Subregnum Eumetazoa Placozoa Orthonectida Rhombozoa Radiata (unranked) Ctenophora Cnidaria Bilateria (unranked) Acoelomorpha Myxozoa Superphylum Deuterostomia Chordata Hemichordata Echinodermata Chaetognatha Xenoturbellida Superphylum Ecdysozoa Kinorhyncha Loricifera Priapulida Nematoda Nematomorpha Onychophora Tardigrada Arthropoda Superphylum Platyzoa Platyhelminthes Gastrotricha Rotifera Acanthocephala Gnathostomulida Micrognathozoa Cycliophora Superphylum Lophotrochozoa Sipuncula Nemertea Phoronida Ectoprocta Bryozoa... In biology, binomial nomenclature is the formal method of naming species. ... Phyla Subregnum Parazoa Porifera Subregnum Eumetazoa Placozoa Orthonectida Rhombozoa Radiata (unranked) Ctenophora Cnidaria Bilateria (unranked) Acoelomorpha Myxozoa Superphylum Deuterostomia Chordata Hemichordata Echinodermata Chaetognatha Xenoturbellida Superphylum Ecdysozoa Kinorhyncha Loricifera Priapulida Nematoda Nematomorpha Onychophora Tardigrada Arthropoda Superphylum Platyzoa Platyhelminthes Gastrotricha Rotifera Acanthocephala Gnathostomulida Micrognathozoa Cycliophora Superphylum Lophotrochozoa Sipuncula Nemertea Phoronida Ectoprocta Bryozoa... 1896 (MDCCCXCVI) was a leap year starting on Wednesday (see link for calendar). ...

Individual Trichoplax are soft-bodied, about 0.5 mm across, and somewhat resemble a large amoeba. The name T. adhaerens was given because it tends to stick to its substrate, including glass pipettes and microscope slides. Its evolutionary relationships are still being investigated, but it may be allied with the cnidarians and ctenophores. Dellaporta et al have reported the complete mitochondrial genome sequence of Trichoplax adhaerens and showed that Placozoa are the most basal (that is, they branched off earliest) living eumetazoan phylum.^[1] Amoeba, amÅ“ba, or ameba is a genus of protozoa that moves by means of temporary projections called pseudopods, and is well-known as a representative unicellular organism. ... Classes Anthozoa - Corals and sea anemones Scyphozoa - Jellyfish Staurozoa - Stalked jellyfish Cubozoa - Sea wasps or box jellyfish Polypodiozoa Hydrozoa - Hydroids, hydra-like animals Cnidaria (silent c - pronounced // from New Latin cnida, fr. ... This article or section is in need of attention from an expert on the subject. ...

Trichoplax lacks organs and most tissues, including nerve cells and a nervous system, although evidence suggests that they evolved from species with nerve cells. It is made up of a few thousand cells of four types in three distinct layers: monociliated dorsal and ventral epithelia cells, ventral gland cells and the syncytial fiber cells. The outermost layer (the monociliated cells) have a single cilium, which allow the adult to move. The epithelia of Trichoplax lack a basal membrane and the cells are connected by belt desmosomes. Lipid inclusions, called 'shiny spheres', are regularly distributed over the dorsal epithelia. In biology, an organ (Latin: organum, instrument, tool) is a group of tissues that perform a specific function or group of functions. ... Biological tissue is a collection of interconnected cells that perform a similar function within an organism. ... The nervous system of an animal coordinates the activity of the muscles, monitors the organs, constructs and also stops input from the senses, and initiates actions. ... cross-section of two motile cilia, showing the 9+2 structure A cilium (plural cilia) or undulipodium (pl. ... Cell adhesion in desmosomes A desmosome (also known as macula adherens (Latin for adhering spot ) is a cell structure specialized for cell-to-cell adhesion. ...

It feeds by absorption and has been observed to form temporary bulges to trap food. It climbs atop its food and uses the ventral surface as a temporary extraorganismal gastric cavity. Digestion is both extracellular and by phagocytosis. Phagocytosis (literally cell-eating) is a form of endocytosis wherein large particles are enveloped by the cell membrane of a (usually larger) cell and internalized to form a phagosome, or food vacuole. ...

When not feeding Trichoplax is actively motile with movement effected by ventral ciliation and by the fiber cell layer and lacks any polarity in its movement.

The haploid number of chromosomes is six. It has the smallest amount of DNA yet measured for any animal with only 50 megabases (80 femtograms per cell). A trichoplax genome project is currently underway.^[2] Haploid (meaning simple in Greek) cells have only one copy of each chromosome. ... The structure of part of a DNA double helix. ...

Putative eggs have been observed, but they degrade at the 32-64 cell stage. Neither embryonic development nor sperm have been observed, however Trichoplax genomes show evidence of sexual reproduction.^[3] Asexual reproduction by binary fission is the primary mode of reproduction observed in the lab.

Trichoplax were discovered on the walls of a marine aquarium in the 1880s, and have rarely been observed in their natural habitat.^[4] The full extent of their natural range is unknown, but they are easily collected in tropical and subtropical latitudes around the world. // Development and commercial production of electric lighting Development and commercial production of gasoline-powered automobile by Karl Benz, Gottlieb Daimler and Maybach First commercial production and sales of phonographs and phonograph recordings. ...

If several Trichoplax are placed in the same dish they interact with each other. Movies of such interactions can be viewed here [1]

References

1. ^ Dellaporta et al (2006). 'Mitochondrial genome of Trichoplax adhaerens supports Placozoa as the basal lower metazoan phylum'. Proceedings of the National Academy of Sciences 103 (23): 8751-6. PMID 16731622.
2. ^ Trichoplax genome project.
3. ^ Signorovitch AY, Dellaporta SL, Buss LW (2005). Molecular signatures for sex in the Placozoa. Proceedings of the National Academy of Sciences 102 (43): 15518-22. PMID 16230622.
4. ^ Maruyama YK (2004). Occurrence in the field of a long-term, year-round, stable population of placozoans. Biol Bull 206 (1): 55-60. PMID 14977730.

The Proceedings of the National Academy of Sciences of the United States of America, usually referred to as PNAS, is the official journal of the United States National Academy of Sciences. ... The Proceedings of the National Academy of Sciences of the United States of America, usually referred to as PNAS, is the official journal of the United States National Academy of Sciences. ...

External links

• The Trichoplax Genome Project at the Yale Peabody Museum
• A Weird Wee Beastie: Trichoplax adhaerens
• Information page from the University of California at Berkeley
• Mitochondrial DNA and 16S rRNA analysis and phylogeny of Trichoplax adhaerens: full text online article Entrez PubMed 12519915.
• Historical overview of Trichoplax research

// Mitochondrial DNA (mtDNA) is DNA that is located in mitochondria. ... A non-coding RNA (ncRNA) is any RNA molecule that functions without being translated into a protein. ... The Entrez logo The Entrez Global Query Cross-Database Search System allows access to databases at the National Center for Biotechnology Information (NCBI) website. ...