Editing Marine worm

{{Short description|Any worm living in a marine environment}}
{{more citations needed|date=October 2022}}
[[File:Proboscis worm.JPG|thumb|right|300px|A large marine worm, ''[[Parborlasia corrugatus]]'' lives at depths of up to {{Convert|3590|m|abbr=on}} in [[Southern Ocean|the ocean]] around [[Antarctica]].]]
<!-- Deleted image removed: [[File:Vesamintifrins.PNG|alt=vesamintifrin|thumb|Respiratory tentacles in vesamintifrins ]] -->
Any [[worm]] that lives in a [[ocean|marine]] [[environment (biophysical)|environment]] is considered a '''water worm.''' Marine worms are found in several different [[phylum (biology)|phyla]], including the [[Platyhelminthes]], [[Nematoda]], [[Annelida]] (segmented worms), [[Chaetognatha]], [[Hemichordata]], and [[Phoronida]]. For a list of marine animals that have been called "sea worms", see [[Sea worm (disambiguation)|sea worm]].

==Reproduction==
Marine worms exhibit numerous types of reproduction, both sexually and asexually. Asexually many are able to reproduce via budding or regeneration. This regeneration is most notably studied in Plathelminths or [[Triclad]], known for being one of the earliest animals to be studied for its regenerative capabilities.<ref>{{Cite journal |last1=Egger |first1=Bernhard |last2=Gschwentner |first2=Robert |last3=Rieger |first3=Reinhard |date=2006-12-05 |title=Free-living flatworms under the knife: past and present |url=https://doi.org/10.1007/s00427-006-0120-5 |journal=Development Genes and Evolution |language=en |volume=217 |issue=2 |pages=89–104 |doi=10.1007/s00427-006-0120-5 |issn=1432-041X |pmc=1784541 |pmid=17146688}}</ref>  Marine worms will also sexually reproduce, internally and externally, with some releasing spawn into the ocean currents. This is in opposition to the much more internal and invasive method displayed by flat-worms called [[Penis fencing]] where hermaphroditic organisms will flight to try and impregnate their opponent while avoiding becoming impregnated.<ref>{{Cite journal |last1=Tong |first1=Samantha Jia Wen |last2=Ong |first2=Rene S.L. |date=June 2020 |title=Mating behavior, spawning, parental care, and embryonic development of some marine pseudocerotid flatworms (Platyhelminthes: Rhabditophora: Polycladida) in Singapore |url=http://dx.doi.org/10.1111/ivb.12293 |journal=Invertebrate Biology |volume=139 |issue=2 |doi=10.1111/ivb.12293 |s2cid=225782903 |issn=1077-8306}}</ref> This method is driven by the biological disadvantages (such as resource need and energy expenditure) behind carrying offspring instead of the more prolific gene passage through multiple impregnations.{{citation needed|date=October 2022}}

==Genetics and taxonomy==
Polynoid scale worms are estimated to have arrived in deep sea ecosystems around sixty million years ago. Through the comparison of 120 genes, researchers came to the conclusion that genes related to DNA repair, recombination, and integration were only present in the deep sea polynoidae, which correlates with the idea that they have to adapt to deal with potential hypoxia in deep sea environments.<ref>{{cite journal | vauthors = Zhang Y, Sun J, Chen C, Watanabe HK, Feng D, Zhang Y, Chiu JM, Qian PY, Qiu JW | display-authors = 6 | title = Adaptation and evolution of deep-sea scale worms (Annelida: Polynoidae): insights from transcriptome comparison with a shallow-water species | journal = Scientific Reports | volume = 7 | issue = 1 | pages = 46205 | date = April 2017 | pmid = 28397791 | pmc = 5387418 | doi = 10.1038/srep46205 | bibcode = 2017NatSR...746205Z }}</ref>

==Feeding methods==
Marine worms can be herbivores, carnivores, parasites, detritivores, or filter feeders, but many strange examples of feeding are seen in this diverse type of animal. The group of [[Siboglinidae]] have developed a relationship with symbiotic bacteria within their gut that often perform chemosynthesis from which the worm benefits. These bacteria reside in a specialized organ called the [[Trophosome]].<ref>{{Cite journal |last1=Leisch |first1=Nikolaus |last2=Dirks |first2=Ulrich |last3=Gruber-Vodicka |first3=Harald R. |last4=Schmid |first4=Markus |last5=Sterrer |first5=Wolfgang |last6=Ott |first6=Jörg A. |date=2011-12-01 |title=Microanatomy of the trophosome region of Paracatenula cf. polyhymnia (Catenulida, Platyhelminthes) and its intracellular symbionts |url=https://doi.org/10.1007/s00435-011-0135-y |journal=Zoomorphology |language=en |volume=130 |issue=4 |pages=261–271 |doi=10.1007/s00435-011-0135-y |issn=1432-234X |pmc=3213344 |pmid=22131640}}</ref> Some worms have an extendable pharynx or a proboscis for consuming prey, while others have developed jaws.{{citation needed|date=October 2022}}

==Circulation==
Marine worms have a variety of circulation and respiration processes. For example, in platyhelminths this is achieved through diffusion of oxygen (as well as other nutrients) across a moist epithelial layer, whereas annelids have a closed circulatory system with blood vessels lining the body.<ref>Collins, James J. "Platyhelminthes." ''Current Biology'' 27.7 (2017): R252-R256.</ref><ref>{{Cite web |date=Oct 24, 2023 |title=Worms: Phyla Platyhelmintes, Nematoda, and Annelida |url=https://manoa.hawaii.edu/exploringourfluidearth/biological/invertebrates/worms-phyla-platyhelmintes-nematoda-and-annelida#:~:text=Annelids%20have%20a%20closed%20circulatory,the%20cells%20of%20the%20body. |website=Exploring Our Fluid Earth |publisher=University of Hawaii at Manoa}}</ref>

Many of these worms have specialized tentacles used for exchanging oxygen and carbon dioxide which also may be used for reproduction. These specialized tentacles allow for gas exchange, further decreasing oxygen content in dead zones and in shallow water, which encourages plant and algae growth.{{citation needed|date=October 2022}}

This quality is also observed in deeper oceans, where tube worms that use respiratory plumes with tentacles perform gas exchange of hydrogen sulfide and methane around hydrothermal vents. These types of circulatory systems differ from marine worms previously mentioned that can perform gas exchange through their entire bodies. This synapomorphy of gas exchange causes even related terrestrial annelids to be restricted to moist environments.{{citation needed|date=October 2022}}

==Environmental niches==
Marine worms are known to inhabit many different environments, having been found in both fresh and saltwater habitats globally.{{citation needed|date=October 2022}}

Some marine worms are [[Tube worm (body plan)|tube worms]], of which the [[giant tube worm]] lives in waters near underwater [[volcanoes]] and can withstand temperatures up to 90&nbsp;°C (194&nbsp;°F). They share this space with fellow polychaetas known as "pompeii worms" that can resist 105&nbsp;°C waters coming out of vents for short periods of time, making them one of the most heat resistant animals ever recorded (Islam and Schulze-Makuch,2007).<ref name=":0">{{Cite journal |last1=Igawa |first1=Momoko |last2=Kato |first2=Makoto |date=2017-09-20 |editor-last=Thuesen |editor-first=Erik V. |title=A new species of hermit crab, Diogenes heteropsammicola (Crustacea, Decapoda, Anomura, Diogenidae), replaces a mutualistic sipunculan in a walking coral symbiosis |journal=PLOS ONE |language=en |volume=12 |issue=9 |pages=e0184311 |doi=10.1371/journal.pone.0184311 |issn=1932-6203 |pmc=5606932 |pmid=28931020|doi-access=free }}</ref>

Some worms can live in extremely deep [[oceanic trench]]es, such as in the Pacific Ocean off the [[Galápagos Islands]].<ref>{{Cite web |title=Giant tubeworm • MBARI |url=https://www.mbari.org/animal/giant-tubeworm/ |access-date=2023-11-06 |website=MBARI |language=en-US}}</ref>

Marine deep sea polychaetes under the genus ''Osedax'' will colonize at whale falls in many different oceans, using a symbiont that can digest the bones within the carcasses (Jones et al,2007) This earned them the common name of "boneworms," and they are speculated to be a keystone species of these types of environments due to lack of organisms in whale falls without observed ''Osedax'' worms. These whale falls remain undigested for many more years than those observed with marine worm cultivations.<ref>{{Cite journal |last1=Jones |first1=William J |last2=Johnson |first2=Shannon B |last3=Rouse |first3=Greg W |last4=Vrijenhoek |first4=Robert C |date=2008-02-22 |title=Marine worms (genus Osedax ) colonize cow bones |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=275 |issue=1633 |pages=387–391 |doi=10.1098/rspb.2007.1437 |pmid=18077256 |pmc=2596828 |issn=0962-8452}}</ref>

In recent years, marine worms (especially those found in the ocean) have been observed ingesting microplastic particles found in the oceans. This trend is concerning many scientists, as marine worms act as an important food source for many fish and wading birds. Marine worms are often [[Keystone Species|keystone species]] in an ecosystem, and the introduction of plastic in the oceans not only diminishes the growth rates of the marine worms, but also affects the food chain of that ecosystem.<ref>{{cite web |title=Limnology and Oceanography |url=https://aslo.org/page/limnology-&-oceanography |work=The Association for the Sciences of Limnology and Oceanography}}</ref>

== References ==
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{{DEFAULTSORT:Marine worm}}
[[Category:Marine animals|Worms]]
[[Category:Worms (obsolete taxon)]]