Talk:Protozoa

Summary of Edits to Protozoa
The article is a mess, and needs a lot more work. I've made some changes to the first few sections (up to the subsection Pellicle, under Characteristics). I'll do more, when time permits.


 * Removed the claim that "the term [Protozoa] is no longer commonly used in modern taxonomy", which is manifestly untrue. In any case, the proper distinction here is not between "modern" and "obsolete" classifications, but between phylogenetic and Linnaean systems of classification.
 * Added Cavalier-Smith's Kingdom Protozoa to the lede.
 * Changed protophyta link. No article exists in Wikipedia, so I linked externally (not ideal, I know)
 * Removed the claim that they're restricted to "aquatic habitats," since many protozoa live in moss and soil (even desert soils).
 * Removed the references to Protozoa as a subkingdom under Animalia, which properly belongs in a section on the history of the term. A discussion of that kind would be useful, but the phrase was out of place, here.
 * Removed the claim that protozoa can be as large as 1 mm, since in the very next sentence it is claimed that they can be as large as 20 cm.
 * Removed the nonsensical claim that xenophyophores "were formerly considered to be part of the protista family." Protists are not a "family," and in any case xenophyophores are still regarded as protists.
 * Removed incomprehensible reference to "tulodens" and rewrote first couple of paragraphs in the Characteristics subsection.
 * Added citations, where needed (for instance, supporting the claim that Entamoeba are more closely related to humans than they are to Euglena).
 * Made numerous small changes to improve grammar, style and flow. Deuterostome (talk) 20:40, 1 May 2015 (UTC)

Summary of edits

 * Rewrote the lede, to cover: 1) the historical taxon 2) the continuing informal use of the term and 3) the modern taxon as defined (mostly) by Tom Cavalier-Smith. It's important to address the latter, because Ruggiero et al., 2015 is likely to form the taxonomic backbone for Catalogue of Life and ITIS databases.
 * Added a section on the history of the term
 * Removed estimated number of species, because that varies according to one's definition of "protozoa." In any case, the estimates themselves are quite variable.
 * Removed mention of light microscope, since that is covered by "microscopic."
 * Removed additional comment on the life strategy of bacterial ectobionts, since it's tangential to the main subject (protozoan pellicles)
 * Added some "citation needed" templates. The section on life cycle and reproduction is very unsatisfactory, but improving it will be difficult, given the range of organisms traditionally roped together under the term "protozoa." Added a brief note on protozoan sex (often misrepresented as a kind of reproduction, whereas it is generally a conjugal exchange of DNA that does not add to the population).
 * Removed nonsensical claim that "an individual protozoan is hermaphroditic."
 * Removed redundant (and rather inaccurate) opening paragraph of Classification section, and removed the link to Kudo's classification system. I think that whole section needs to be rethought, but that is a job for another day.
 * Rewrote and edited for style and clarity
 * Added several images,including a new one from my own collection. Deuterostome (talk) 00:57, 10 June 2015 (UTC)

Summary of Edits

 * Rearranged and edited the lede, using secondary sources & emphasizing the use of protozoa and protozoans as an informal term of convenience, rather than a taxon. This is, by far, the most common sense in which the term "protozoa" is used, currently, both in popular and scholarly sources. The second paragraph deals with the paraphyletic group Protozoa (which, in its current form, excludes many organisms commonly referred to as protozoans).


 * Added a collage of images showing a few representative species (as on Algae, [Eukaryotes]], etc).


 * Added table showing sizes of a few representive protozoan species


 * Multiple small edits on habitat, feeding, motility, pellicle and life cycle


 * Reorganized the Classification section, which mostly deals with the now-obsolete phenetic scheme used in older texts, such as Kudo's. Eliminated the second list of sub-groups. Many schemes were used in the 20th century, but it serves no purpose to include them all in this article (this is not Wikispecies).


 * Dropped a couple of uncited claims in Ecological role (this section needs to be expanded)  Deuterostome  (Talk) 17:45, 27 March 2018 (UTC)

No reproduction section
I don’t understand why this article doesn’t have a reproduction section. Articles like animal and Fungus have a reproduction section. Also the article on sex says Protozoa reproduce.CycoMa (talk) 02:30, 2 June 2021 (UTC)


 * If it is alive, it reproduces. This article is still a mess. Wikipedia needs to hire some writers with subject knowledge to spruce up the important articles. Billyshiverstick (talk) 01:36, 9 October 2023 (UTC)

Please explain why the clade thing is so important
In the lead there's a section that starts with ‘By the 1970's, it became usual to require’. That and the following sentences makes it sound like it's a purely administrative decision, as if the grouping protozoa has merely gone out of fashion. This is not however how the issue is experienced in the field! Rather it's regarded as a fundamental point and the wording in the article should reflect that. Perhaps an image of a cladogram that shows various former protozoa in their new branches of the tree of life might also help. — Preceding unsigned comment added by 77.61.180.106 (talk) 00:18, 22 October 2021 (UTC)


 * I agree that a diagram and whatever their "group" name is now would help. The issue is important, because until recently, living organisms were grouped by common characteristics, like fish, breathe through gills and live in water, bony fish, have bones, etc. Since DNA sequencing became a thing, groups are now more about how they evolved, and so Protozoans no longer form a group in the same way they did for centuries. I too have found this article frustrating, in that it doesn't tell me what group they are in now, which is why I came to the talk page, to see if anyone else was bugged by this. I'll try and clarify this in the text, if I can. cheers Billyshiverstick (talk) 01:31, 9 October 2023 (UTC)

Wiki Education assignment: General Biology I Honors
— Assignment last updated by Anoshah04 (talk) 16:38, 1 December 2022 (UTC)


 * Hi Anoshah, could you please have someone with biology chops place Protozoa as a group within the evolutionary tree, perhaps with some diagrams? OK, they aren't animals any more, but exactly what are they? How do they fit? Or explain that they no longer form a discrete group. best regards Billyshiverstick (talk) 01:34, 9 October 2023 (UTC)

Small issue: Not sure how it was spelled in ancient times, but I'm pretty sure the Germans have been spelling it Tier and not Thier for a long time now, most probably before Pluto was a planet. Is there any source for the Th spelling ? 104.156.66.98 (talk) 20:15, 22 April 2024 (UTC)


 * Yes. Goldfuss himself used that spelling in 1817, when the word "Urthieres" was coined. The term appears on p. 21 of his book Ueber die Entwicklungsstufen des Thieres. Also, the etymology section of the Protozoa article cites the paper "Protozoa, Protista, Protoctista: what's in a name?" (Rothschild, 1989), which contains the following passage: "As Edward A. Minchin  explained, 'the name Protozoa was first used. . . as an equivalent of the German word Urthiere, meaning animals of a primitive or archaic type' (11912:2).  The word is derived from the Greek  words 'proto,' meaning 'first,'  and 'zoon,' meaning  'animal.'"      Deuterostome  (Talk) 01:30, 23 April 2024 (UTC)