Trichoplax Adhaerens

Trichoplax adhaerens is the only extant representative of phylum Placozoa, which is a basal group of multicellular animals (metazoa). Trichoplax are very flat creatures around a millimeter in diameter, lacking any organs or internal structures. They have two cellular layers: the top epitheloid layer is made of ciliated "cover cells" flattened toward the outside of the organism, and the bottom layer is made up of cylinder cells that possess cilia used in locomotion, and gland cells that lack cilia. Between these layers is the fiber syncytium, a liquid-filled cavity strutted open by star-like fibers.

Trichoplax feed by absorbing food particles—mainly microbes—with their underside. They generally reproduce asexually, by dividing or budding, but can also reproduce sexually. Though Trichoplax has a small genome in comparison to other animals, nearly 87% of its 11,514 predicted protein-coding genes are identifiably similar to known genes in other animals.

Read more about Trichoplax Adhaerens:  Discovery, Morphology, Epitheloid, Fiber Syncytium, Genetics, Relationship With Animals, Distribution and Habitat, Feeding and Symbionts, Locomotion, Regeneration, Reproduction, Role As A Model Organism, Systematics