Acanthamoeba pyriformis is a species of the genus "Acanthamoeba" with unique fruiting system with a sporocarp stage and pyriform spores. It is primarily found in leaf litter in multiple types of climates.
Taxonomy.
"Acanthamoeba pyriformis" is classified in the genus "Acanthamoeba". "A. pyriformis" was originally placed in genus "Protostelium" when it was described by Olive and Stoianovitch in 1969 based on morphology. The species showed similarities such as fruiting body development and morphology and more to other "Protostelia" so the researchers classified it as such, naming the species "pyriformis" due to its pyriform, pear-shaped, spores. Using a combination of morphology, behavior, and DNA sequencing, it was reclassified into "Acanthamoeba".
Ecology.
"Acanthamoeba" species are generally described as opportunistic, meaning that it can survive in many different environments such as sea water, natural water, tap water, soil, and even humans. However, "A. pyriformis" is found primarily in leaf litter and can also be found on other types of decaying organic matter. In one study, this organism was found in Costa Rica, but it is found in other parts of the world as well.
Morphology and behavior.
The organism "Acanthamoeba pyriformis" was originally deemed "Protostelium" due to its ability to build sporocarps. However with new developments in DNA sequencing and comparison, scientists began to question this organism's original classification. Scientists then moved it into the "Acanthamoeba" genus. This made it the first species of "Acanthamoeba" to include facultative sporocarpic fruiting in its life cycle. During the locomotion stage of their life, the amoebae are flat and can vary in shape. They are typically longer than their width, with an average cell length of 26.9 micrometers. The amoeba is led by a lobose, hyaloplasmic pseudopodium that usually contains acanthopodia. Which are finger-like projections from the cell's body. The cell's granular cytoplasm contains a single, spherical to subspherical nucleus. When forming cysts, the cysts are isodiametric with stellate knobs and an average diameter of 13.1 micrometers. Sporocarps develop as the amoeba becomes refractile. A stalk is formed and deposited in the lower portion of the sporogen. At maturity, the sporogen lays down a spore wall and becomes an obpyriform spore. Then air can shed the spore and disperse it. The genus "Acanthamoeba" typically has a life cycle that has a trophozoite stage and a cyst stage. "A. pyriformis" is unique because it also includes the sporocarp stage. The trophozoite stage is the feeding stage where the amoeba is most active. The cyst stage is the dormant stage that allows the organism to survive unfavorable conditions. The sporocarp stage, unique to this organism among the genus "Acanthamoeba", is a structure that contains spores. This is a facultative stage, so it doesn't occur in all individuals.