Editing Ctenophora (section)

=== Distribution ===

Ctenophores are found in most marine environments: from polar waters at −2&nbsp;°C to the tropics at 30&nbsp;°C; near coasts and in mid-ocean; from the surface waters to the ocean depths at more than 7000 meters.<ref>{{Cite journal |last1=Winnikoff |first1=Jacob R. |last2=Haddock |first2=Steven H. D. |last3=Budin |first3=Itay |date=2021-11-01 |title=Depth- and temperature-specific fatty acid adaptations in ctenophores from extreme habitats |journal=[[Journal of Experimental Biology]] |volume=224 |issue=21 |pages=jeb242800 |doi=10.1242/jeb.242800 |pmc=8627573 |pmid=34676421}}</ref> The best-understood are the [[genus|genera]] ''Pleurobrachia'', ''Beroe'' and ''[[Mnemiopsis]]'', as these [[plankton]]ic coastal forms are among the most likely to be collected near shore.<ref name="Haddock204goldenAgeofGelata" /><ref name="Haddock2007ComparativeFeeding" />

In 2013 ''Mnemiopsis'' was recorded in lake Birket Qarun, and in 2014 in [[lake El Rayan]] II, both near [[Faiyum]] in Egypt, where they were accidentally introduced by the transport of fish (mullet) fry. Though many species prefer brackish waters like estuaries and coastal lagoons in open connection with the sea, this was the first record from an inland environment. Both lakes are saline, with Birket Qarun being hypersaline, and shows that some ctenophores can establish themselves in saline limnic environments without connection to the ocean. In the long run, it is not expected the populations will survive. The two limiting factors in saline lakes are availability of food and a varied diet, and high temperatures during hot summers. Because a parasitic isopod, ''Livoneca redmanii'', was introduced at the same time, it is difficult to say how much of the ecological impact of invasive species is caused by the ctenophore alone.<ref name="El-Shabrawy Dumont 2016 pp. 21–24">{{cite journal |first1=Gamal |last1=el-Shabrawy |first2=Henri |last2=Dumont |year=2016 |title=First record of a ctenophore in lakes: The comb-jelly ''Mnemiopsis leidyi'' ({{small|A. Agassiz, 1865}}) invades the Fayum, Egypt |journal=BioInvasions Records |volume=5 |issue=1 |pages=21–24 |s2cid=90377075 |doi=10.3391/bir.2016.5.1.04 |doi-access=free}}</ref><ref>{{cite journal |last1=Mohammed-Geba |first1=Khaled |last2= Sheir |first2=Sherin |last3=Aguilar |first3=Robert |last4= Ogburn |first4=Matthew |last5= Hines |first5=Anson |last6= Khalafallah |first6=Hussain |last7=el-Kattan |first7=Ahmed |last8= Hassab el-Nabi |first8=Sobhy |last9=Galal-Khallaf |first9=Asmaa |display-authors=6 |year=2019 |title=Molecular and morphological confirmation of an invasive American isopod; ''Livoneca redmanii'' ({{small|Leach, 1818}}), from the Mediterranean region to Lake Qaroun, Egypt |journal=Egyptian Journal of Aquatic Biology & Fisheries |volume=23 |issue=4 |pages=251–273 |doi=10.21608/ejabf.2019.54062 |url=https://journals.ekb.eg/article_54062_2d04ff7853ceefc5fbb3f3c23fb58f3c.pdf}}</ref>