Editing Percolozoa (section)

==Characteristics==
Most Percolozoa are found as bacterivores in soil, fresh water and occasionally in the ocean.<ref>{{Citation |last=Esteban |first=Genoveva F. |title=Free-Living Protozoa |date=2015 |work=Thorp and Covich's Freshwater Invertebrates |pages=122 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780123850263000073 |access-date=2024-12-14 |publisher=Elsevier |language=en |doi=10.1016/b978-0-12-385026-3.00007-3 |isbn=978-0-12-385026-3 |last2=Finlay |first2=Bland J. |last3=Warren |first3=Alan}}</ref> The only member of this group that is infectious to humans is ''[[Naegleria fowleri]]'', the causative agent of the often fatal disease [[amoebic meningitis]].<ref name=":0">{{Citation |last=Pánek |first=Tomáš |title=Heterolobosea |date=2016 |work=Handbook of the Protists |pages=1–42 |editor-last=Archibald |editor-first=John M. |url=http://link.springer.com/10.1007/978-3-319-32669-6_10-1 |access-date=2024-12-14 |place=Cham |publisher=Springer International Publishing |language=en |doi=10.1007/978-3-319-32669-6_10-1 |isbn=978-3-319-32669-6 |last2=Simpson |first2=Alastair G. B. |last3=Brown |first3=Matthew W. |last4=Dexter Dyer |first4=Betsey |editor2-last=Simpson |editor2-first=Alastair G.B. |editor3-last=Slamovits |editor3-first=Claudio H. |editor4-last=Margulis |editor4-first=Lynn}}</ref> The group is closely related to the [[Euglenozoa]], and share with them the unusual characteristic of having [[mitochondrion|mitochondria]] with discoid [[crista]]e.<ref name="pmid14657102" /> The presence of a ventral feeding groove in the flagellate stage, as well as other features, suggests that they are part of the [[Excavata]] group.<ref name="CavSmith 2021" />

The amoeboid stage is roughly cylindrical, typically around [[1 E-5 m|20–40 μm]] in length. They are traditionally considered lobose amoebae, but are not related to the others, and unlike them, do not form true lobose [[pseudopods]].  Instead, they advance by eruptive waves, where hemispherical bulges appear from the front margin of the cell, which is clear. The flagellate stage is slightly smaller, with two or four anterior flagella anterior to the feeding groove.<ref name=":0" />

Usually, the amoeboid form is taken when food is plentiful, and the flagellate form is used for rapid locomotion. However, not all members are able to assume both forms. The genera ''[[Percolomonas]]'', ''[[Lyromonas]]'', and ''[[Psalteriomonas]]'' are known only as flagellates, while ''[[Vahlkampfia]]'', ''[[Pseudovahlkampfia]]'', and most [[acrasid]]s do not have flagellate stages. As mentioned above, under unfavourable conditions, the acrasids aggregate to form sporangia. These are superficially similar to the sporangia of the [[dictyostelid]]s, but the amoebae only aggregate as individuals or in small groups and do not die to form the stalk.<ref name=":0" />

[[File:2023 Heterolobosean.svg|center|thumb|upright=2|{{center|'''Representation of a heterolobosean'''}}]]