Editing Cnidocyte (section)

== Types of cnidae ==
Over 30 types of cnidae are found in different cnidarians. They can be divided into the following groups:
# Nematocyst (Penetrant or Piercing<ref name=":1">{{Cite journal |last1=Babonis |first1=Leslie S. |last2=Enjolras |first2=Camille |last3=Reft |first3=Abigail J. |last4=Foster |first4=Brent M. |last5=Hugosson |first5=Fredrik |last6=Ryan |first6=Joseph F. |last7=Daly |first7=Marymegan |last8=Martindale |first8=Mark Q. |date=2023-02-16 |title=Single-cell atavism reveals an ancient mechanism of cell type diversification in a sea anemone |url=https://rdcu.be/dqIyq |journal=Nature Communications |language=en |volume=14 |issue=1 |page=885 |doi=10.1038/s41467-023-36615-9 |pmid=36797294 |pmc=9935875 |bibcode=2023NatCo..14..885B |issn=2041-1723}}</ref>): The penetrant or stenotele is the largest and most complex nematocyst. When discharged, it pierces the skin or [[chitin]]ous exoskeleton of the prey and injects the venomous fluid, [[hypnotoxin]], that either paralyzes the victim or kills it.
# Ptychocysts (Glutinant or Adhesive<ref name=":1" />): a sticky surface used to stick to prey, referred to as [[ptychocyst]]s and found on burrowing (tube) anemones, which help create the tube in which the animal lives
# Spirocysts (Volvent or Ensnaring<ref name=":1" />): The volvent or desmoneme is a small and pear-shaped cnidocyte. It contains a short, thick, spineless, smooth and elastic thread tube forming a single loop and closed at the far end. When discharged, it tightly coils around the prey. They are the smallest cnidocytes. A lasso-like string is fired at prey and wraps around a cellular projection on the prey, which are referred to as spirocysts.

Cnidocyte subtypes can be differentially localized in the animal. In the sea anemone ''[[Nematostella vectensis]]'', the majority of its non-penetrant sticky cnidocytes, the spherocytes, are found in the tentacles, and are thought to help with prey capture by sticking to the prey. By contrast, the two penetrant types of cnidocytes present in this species display a much broader localization, on the outer [[epithelium|epithelial]] layer of the tentacles and body column, as well as on the [[pharynx]] epithelium and within [[mesenteries]].<ref name=":03">{{Cite journal|last1=Zenkert|first1=Claudia|last2=Takahashi|first2=Toshio|last3=Diesner|first3=Mark-Oliver|last4=Özbek|first4=Suat|date=2011-07-28|title=Morphological and Molecular Analysis of the Nematostella vectensis Cnidom|journal=PLOS ONE|volume=6|issue=7|pages=e22725|doi=10.1371/journal.pone.0022725|issn=1932-6203|pmc=3145756|pmid=21829492|bibcode=2011PLoSO...622725Z|doi-access=free}}</ref>

The diversity of cnidocytes types correlates with the expansion and diversification of structural cnidocyst genes like mini collagen genes.<ref name=":12">{{Cite journal|last1=Khalturin|first1=Konstantin|last2=Shinzato|first2=Chuya|last3=Khalturina|first3=Maria|last4=Hamada|first4=Mayuko|last5=Fujie|first5=Manabu|last6=Koyanagi|first6=Ryo|last7=Kanda|first7=Miyuki|last8=Goto|first8=Hiroki|last9=Anton-Erxleben|first9=Friederike|last10=Toyokawa|first10=Masaya|last11=Toshino|first11=Sho|date=May 2019|title=Medusozoan genomes inform the evolution of the jellyfish body plan|journal=Nature Ecology & Evolution|volume=3|issue=5|pages=811–822|doi=10.1038/s41559-019-0853-y|issn=2397-334X|pmid=30988488|doi-access=free|bibcode=2019NatEE...3..811K |url=https://oist.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1020&item_no=1&attribute_id=22&file_no=1}}</ref> [[Minicollagen]] genes form compact gene clusters in Cnidarian [[genome]]s, suggesting a diversification through gene duplication and subfunctionalization. [[Anthozoan]]s display less capsule diversity and a reduced number of mini collagen genes, and [[medusozoans]] have more capsule diversity (about 25 types) and a vastly expanded minicollagen genes repertoire.<ref name=":12" /> In the [[sea anemone]] ''[[Nematostella vectensis]]'', some minicollagens display a differential expression pattern in different cnidocytes subtypes.<ref name=":03" /><ref>{{Cite journal|last1=Sebé-Pedrós|first1=Arnau|last2=Saudemont|first2=Baptiste|last3=Chomsky|first3=Elad|last4=Plessier|first4=Flora|last5=Mailhé|first5=Marie-Pierre|last6=Renno|first6=Justine|last7=Loe-Mie|first7=Yann|last8=Lifshitz|first8=Aviezer|last9=Mukamel|first9=Zohar|last10=Schmutz|first10=Sandrine|last11=Novault|first11=Sophie|date=31 May 2018|title=Cnidarian Cell Type Diversity and Regulation Revealed by Whole-Organism Single-Cell RNA-Seq|journal=Cell|volume=173|issue=6|pages=1520–1534.e20|doi=10.1016/j.cell.2018.05.019|issn=1097-4172|pmid=29856957|doi-access=free}}</ref>