View source for Sea lamprey

{{Short description|Species of fish native to the Northern Hemisphere}}
{{Speciesbox
| name = Sea lamprey
| image = Petromyzon marinus.001 - Aquarium Finisterrae.jpg
| image_caption = Multiple sea lampreys in the [[Aquarium Finisterrae]], [[Spain]]
| image2 = Petromyzon marinus2.jpg
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=NatureServe |date=2013 |title=''Petromyzon marinus'' |volume=2013 |page=e.T16781A18229984 |doi=10.2305/IUCN.UK.2013-1.RLTS.T16781A18229984.en |access-date=19 November 2021}}</ref>
| parent_authority = [[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]]
| taxon = Petromyzon marinus
| authority = [[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]]
| synonyms = {{collapsible list|bullets = true
|title=<small>Genus synonymy</small>
| ''Ammocoetus'' <small>Dumeril 1812 non Erichson 1847</small>
| ''Petromyzon'' (''Bathymyzon'') <small>Gill 1883</small>
| ''Bathymyzon'' <small>(Gill 1883)</small>
| ''Oceanomyzon'' <small>Fowler 1908</small>
| ''Lampreda'' <small>Rafinesque 1815 nomen nudum</small>
| ''Pricus'' <small>Rafinesque 1815 nomen nudum</small>
}}
{{collapsible list|bullets = true
|title=<small>Species synonymy</small>
| ''Lampetra marina'' <small>(Linnaeus 1758)</small>
| ''Petromyzon'' (''Bathymyzon'') ''bairdii'' <small>Gill 1883</small>
| ''Bathymyzon bairdii'' <small>(Gill 1883)</small>
| ''Petromyzon ruber'' <small>Lacepède 1800</small>
| ?''Petromyzon lampetrus'' <small>Forsskål 1775 non Pallas 1814</small>
| ''Petromyzon lampetrus'' <small>Pallas 1814 non Forsskål 1775</small>
| ''Petromyzon maximus'' <small>Cuvier 1816</small>
| ''Petromyzon americanus'' <small>Lesueur 1818</small>
| ''Petromyzon nigricans'' <small>Lesueur 1818</small>
| ''Ammocoetes bicolor'' <small>Lesueur 1818</small>
| ?''Petromyzon adriaticus'' <small>Nardo 1847</small>
| ''Petromyzon maculosus'' <small>Gronow 1854</small>
| ''Petromyzon marinus dorsatus'' <small>Wilder 1883</small>
| ''Petromyzon marinus unicolor'' <small>Gage 1928</small>
| ''Oceanomyzon wilsoni'' <small>Fowler 1908</small>
| ?''Petromyzon leucopterus'' <small>Rafinesque 1818</small>
| ?''Petromyzon maurari'' <small>DeKay 1840</small>
}}
| synonyms_ref = <ref>{{Cite web|last1=Froese|first1=R.|last2=Pauly|first2=D.|year=2017|title=Petromyzontidae |url=http://www.fishbase.se/summary/FamilySummary.php?ID=1|website=[[FishBase]] version (02/2017)|access-date=18 May 2017}}</ref><ref>{{Cite web|title=Petromyzontidae |url=http://deeplyfish.com/wp-content/uploads/2017/03/Family-Petromyzontidae-PDF.pdf|website=Deeplyfish – fishes of the world|access-date=18 May 2017}}</ref>
}}

The '''sea lamprey''' ('''''Petromyzon marinus''''') is a [[parasitic]] [[lamprey]] native to the Northern Hemisphere. It is sometimes referred to as the "vampire fish". 

It was likely introduced to the [[Great Lakes region]] through the [[Erie Canal]] in 1825 and the [[Welland Canal]] in 1919 where it has attacked native fish such as [[lake trout]], [[lake whitefish]], [[Freshwater whitefish|chub]], and [[Northern cisco|lake herring]]. Sea lampreys are considered a [[invasive species|pest]] in the Great Lakes region as each individual has the potential of killing 40 pounds of fish through its 12–18 month feeding period.
 
==Description==
{{broader|Lamprey|topic=general lamprey morphology}}
The sea lamprey has an [[eel]]-like body without paired [[fin]]s. Its mouth is jawless, round and sucker-like, and as wide or wider than the head; sharp teeth are arranged in many concentric circular rows around a sharp, rasp-like tongue. There are seven branchial or [[gill]]-like openings behind the eye. Sea lampreys are olive or brown-yellow on the dorsal and lateral part of the body, with some black marblings, with lighter coloration on the belly. Within their seven-year lifespans, adults can reach a length of up to {{convert|120|cm|in|abbr=on}} and a body weight up to {{convert|2.3|kg|lb |abbr=on}}.<ref name=fishbase/><ref name=":0">{{Cite journal |last1=Applegate |first1=Vernon C. |last2=Moffett |first2=James W. |date=1955 |title=The Sea Lamprey |url=https://www.jstor.org/stable/24944609 |journal=Scientific American |volume=192 |issue=4 |pages=36–41 |doi=10.1038/scientificamerican0455-36 |jstor=24944609 |bibcode=1955SciAm.192d..36A |issn=0036-8733|url-access=subscription }}</ref>

===Etymology===
The etymology of the genus name ''Petromyzon'' is from ''[[:wikt:petro-|petro-]]'' "stone" and ''[[:wikt:μυζάω|myzon]]'' "sucking"; ''marinus'' is Latin for "of the sea".

==Distribution and habitat==
The species is found in the northern and western [[Atlantic Ocean]] along the shores of Europe and North America, in the western [[Mediterranean Sea]], the [[Black Sea]], and as an invasive species in the [[Great Lakes]].<ref name="iucn status 19 November 2021" /> They have been found at depths up to 4000 meters and can tolerate temperatures of {{convert|1|-|20|C|F}}.<ref name=fishbase>{{cite web|url=http://www.fishbase.org/summary/Petromyzon-marinus.html|title=''Petromyzon marinus'' – Sea lamprey|website=FishBase}}</ref> 

In North America, they are native to the [[Connecticut River]] basin in the United States, and invasive to the inland [[Great Lakes]] and [[Lake Champlain]] in [[New York (state)|New York]] and [[Vermont]].<ref>{{Cite web|first=Alec |last=Snyder|title=A 'vampire fish' is spawning in Vermont's waters. Experts say most of them are nothing to worry about|url=https://www.cnn.com/2020/06/25/us/vampire-fish-vermont-trnd/index.html|access-date=2020-06-30|website=CNN|date=25 June 2020 }}</ref>
The largest European populations of sea lampreys are located throughout the southwestern areas of Europe (north-central Portugal, north-northwest of Spain, and west–southwest of France).<ref>{{cite journal | last1 = Silva | first1 = S. | last2 = Vieira-Lanero | first2 = R. | last3 = Barca | first3 = S. | last4 = Cobo | first4 = F. | year = 2016 | title = Densities and biomass of larval Sea Lamprey populations (''Petromyzon marinus'' Linnaeus, 1758) in North West Spain and data comparisons with other European regions | journal = Marine and Freshwater Research | volume =  68| pages = 116 | doi = 10.1071/MF15065 }}</ref> These countries also support the main fisheries of the species.<ref>{{cite book|author=Araújo, M.J., Silva, S., Stratoudakis, Y., Gonçalves, M., Lopez, R., Carneiro, M., Martins, R., Cobo, F. and Antunes, C. |year=2016| chapter=Ch. 20. Sea lamprey fisheries in the Iberian Peninsula|pages= 115–148|title=Jawless Fishes of the World|volume =2|editor=A. Orlov and R. Beamish|publisher= Cambridge Scholars Publishing|chapter-url=https://www.researchgate.net/publication/297740129|isbn=978-1-4438-8582-9}}</ref>

==Ecology==
Sea lampreys are [[Fish migration#Classification|anadromous]]; from their lake or sea habitats, they migrate up rivers to spawn. Females deposit a large number of eggs in nests made by males in the substrate of streams with moderately strong current. Spawning is followed by the death of the adults. Larvae burrow in the sand and silt bottom in quiet water downstream from spawning areas and filter-feed on plankton and detritus.<ref name="iucn status 19 November 2021" />

After several years in freshwater habitats, the larvae undergo a metamorphosis that allows young, post-metamorphic lampreys to migrate to the sea or lakes, and start the adult [[hematophagous]] method of feeding.<ref>{{cite journal | last1 = Silva | first1 = S. | last2 = Servia | first2 = M. J. | last3 = Vieira-Lanero | first3 = R. | last4 = Cobo | first4 = F. | year = 2013a | title = Downstream migration and hematophagous feeding of newly metamorphosed sea lampreys (''Petromyzon marinus'' Linnaeus, 1758) | journal = Hydrobiologia | volume = 700 | pages = 277–286 | doi = 10.1007/s10750-012-1237-3 | s2cid = 16752713 }}</ref> Some individuals start hematophagous feeding in the river before migrating to the sea,<ref>{{cite journal|author=Silva, S., Servia, M. J., Vieira-Lanero, R., Nachón, D. J. & Cobo, F. |year=2013|title= Hematophagous feeding of newly metamorphosed European sea lampreys ''Petromyzon marinus'' on strictly freshwater species|journal= Journal of Fish Biology|volume=82|issue=5|pages=1739–1745|doi=10.1111/jfb.12100|pmid=23639169|bibcode=2013JFBio..82.1739S }}</ref> where sea lampreys prey on a wide variety of fish.<ref>{{cite journal | last1 = Silva | first1 = S. | last2 = Araújo | first2 = M. J. | last3 = Bao | first3 = M. | last4 = Mucientes | first4 = G. | last5 = Cobo | first5 = F. | year = 2014 | title = The haematophagous feeding stage of anadromous populations of sea lamprey ''Petromyzon marinus'': low host selectivity and wide range of habitats | journal = Hydrobiologia | volume = 734 | issue = 1| pages = 187–199 | doi=10.1007/s10750-014-1879-4| hdl = 10261/98126| s2cid = 17796757 | hdl-access = free }}</ref>

The lamprey uses its suction cup-like mouth to attach itself to the skin of a fish and rasps away tissue with its sharp, probing tongue and [[keratin]]ized teeth. A fluid produced in the lamprey's mouth, called ''lamphredin'',<ref>[https://www.researchgate.net/figure/23986375_fig1_Fig-1-Effect-of-lamphredin-from-the-buccal-glands-of-lampreys-L-japonica-on-the Fig. 1 Effect of lamphredin from the buccal glands of lampreys] in {{cite journal|doi=10.1007/s00424-008-0631-1|pmid=19198874|title=Suppression of neuronal excitability by the secretion of the lamprey (''Lampetra japonica'') provides a mechanism for its evolutionary stability|journal=Pflügers Archiv: European Journal of Physiology|volume=458|issue=3|pages=537–545 |year=2009 |last1=Chi |first1=Shaopeng |last2=Xiao |first2=Rong |last3=Li| first3=Qingwei |last4=Zhou |first4=Liwei |last5=He |first5=Rongqiao| last6=Qi |first6=Zhi|s2cid=375194}}</ref> prevents the victim's blood from clotting. Victims typically die from excessive blood loss or infection. After one year of hematophagous feeding, lampreys return to the river to spawn and die, a year and a half after the completion of metamorphosis.<ref>{{cite journal|author=Silva, S., Servia, M.J., Vieira-Lanero, R., Barca, S. & Cobo, F. |title=Life cycle of the sea lamprey ''Petromyzon marinus'': duration of and growth in the marine life stage|journal=Aquatic Biology |volume=18 |pages=59–62 |doi=10.3354/ab00488 |year=2013|doi-access=free }}</ref>

Lampreys are considered a delicacy in some parts of Europe, and are seasonally available in France, Spain, and Portugal. They are served pickled in Finland.<ref>{{cite web | url=https://www.atlasobscura.com/foods/lamprey-portugal | title=Lamprey: a prehistoric sea monster sucks blood, then gets cooked in its own| website=Atlas Obscura | year=2018 | access-date=15 September 2018}}</ref> Mostly known for preparing cooked or grilled [[European river lamprey|river lamprey]], the sea lamprey occasionally is caught in the rivers of [[Latvia]] as well together with river lampreys.<ref>{{Cite web |date=2023-05-20 |title=Kas ir nēģis? Zinātniekiem vienprātības nav |trans-title=What is lamprey? Scientists are divided |url=https://www.lsm.lv/raksts/dzive--stils/vide-un-dzivnieki/20.05.2023-kas-ir-negis-zinatniekiem-vienpratibas-nav.a508833/ |access-date=2024-07-24 |website=[[lsm.lv]] |language=lv}}</ref>

== Physiology ==
[[File:Sea_lamprey_on_brown_trout_flipped.jpg|thumb|Two sea lamprey preying on a [[brown trout]]|alt=]] 
Due to its lifecycle that switches between fresh and salt water, the sea lamprey is adapted to tolerate a wide range of [[salinity|salinities]]. Cell membranes on the surface of the gills are major contributors to [[ionoregulation]]. Changes in membrane composition influence the movement of different ions across the membrane, changing amounts of components to change the membranes' environment. In some instances, the sea lamprey has adapted to living exclusively in fresh water, as evidenced by the population in the Great Lakes.<ref name=":0" />

As the larvae (called '''ammocoetes''') move towards the oceans, the ratio between [[saturated fatty acids]] (SFA) and [[polyunsaturated fatty acids]] (PUFA) in the gills shifts towards higher amounts of SFA, as they affect the fluidity of the membrane, and higher levels of SFA lead to a decrease in permeability compared to PUFA.<ref>{{cite journal|last1=João|first1=Maria|last2=Machado|first2=Maria|last3=Ferreira|first3=Ana|last4=Quintella|first4=Bernardo|last5=Almeida|first5=Pedro|title=Structural lipid changes and Na<sup>+</sup>/K<sup>+</sup>-ATPase activity of gill cells' basolateral membranes during saltwater acclimation in sea lamprey (''Petromyzon marinus'', L.) juveniles|journal=Comparative Biochemistry and Physiology|date=2015|volume=189|pages=67–75|doi=10.1016/j.cbpa.2015.07.018|pmid=26244517|hdl=10174/16601|hdl-access=free}}</ref> Lamprey ammocoetes have a relatively narrow range of salinity tolerance, but become better able to withstand wider ranges of salinity concentrations as they reach later stages of life. Tight regulation of [[Na/K-ATPase]] and an overall decrease in expression of [[Proton ATPase|H-ATPase]] assists in regulating the lamprey's internal fluid and ion balance as it moves to areas of higher salinity.<ref>{{cite journal|last1=Reis-Santos|first1=Patrick|last2=McCormick|first2=Stephen|last3=Wilson|first3=Jonathan|title=Ionoregulatory changes during metamorphosis and salinity exposure of juvenile sea lamprey (''Petromyzon marinus'' L.)|journal=The Journal of Experimental Biology|date=2008|volume=211|issue=Pt 6|pages=978–988|doi=10.1242/jeb.014423|pmid=18310123|doi-access=free}}</ref>

Lampreys also maintain acid-base [[homeostasis]]. When introduced to higher levels of acids, they are able to excrete excess acids at higher rates than most other saltwater fishes, and in much shorter times, with the majority of the transfer of ions occurring at the gill surface.<ref>{{cite journal|last1=Wilkie|first1=Michael|last2=Couturier|first2=Jennifer|last3=Tufts|first3=Bruce|title=Mechanisms of acid-base regulation in migrant sea lampreys (''Petromyzon marinus'') following exhaustive exercise|url=http://jeb.biologists.org/content/201/9/1473|journal=The Journal of Experimental Biology|date=1998|volume=201|issue=9 |pages=1473–1482|doi=10.1242/jeb.201.9.1473 |pmid=9547326|url-access=subscription}}</ref>

Sea lampreys parasitize other fishes for their diet, including [[elasmobranch]]s such as sharks and rays, which have naturally high levels of [[urea]] in their blood. Urea is toxic to most fishes in high concentrations, and is usually excreted immediately. Lampreys are able to tolerate much higher concentrations than most other fish and excrete it at extremely high rates, obtained from ingested blood. [[TMAO|Trimethylamine oxides]] present in ingested elasmobranch blood aid in counteracting the detrimental effects of high urea concentration in the lamprey's bloodstream as it feeds.<ref>{{cite journal|last1=Wilkie|first1=Michael|last2=Turnbull|first2=Steven|last3=Bird|first3=Jonathan|last4=Wang|first4=Yuxiang|last5=Claude|first5=Jaime|last6=Youson|first6=John|title=Lamprey parasitism of sharks and teleosts: High capacity urea excretion in an extant vertebrate relic|journal=Comparative Biochemistry and Physiology|date=2004|volume=138|issue=4|pages=485–492|doi=10.1016/j.cbpb.2004.06.001|pmid=15369838}}</ref>

===Immunology===
Two presumptive [[APOBEC|apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC)]]s expressed in [[lymphocyte]]s—[[CDA1 (APOBEC)|CDA1]] and [[CDA2 (APOBEC)|CDA2]]—have been discovered in ''P. marinus''.<ref name="Boehm-et-al-2018">{{cite journal | last1=Boehm | first1=Thomas | last2=Hirano | first2=Masayuki | last3=Holland | first3=Stephen J. | last4=Das | first4=Sabyasachi | last5=Schorpp | first5=Michael | last6=Cooper | first6=Max D. | title=Evolution of Alternative Adaptive Immune Systems in Vertebrates | journal=[[Annual Review of Immunology]] | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | volume=36 | issue=1 | date=2018-04-26 | issn=0732-0582 | doi=10.1146/annurev-immunol-042617-053028 | pages=19–42| pmid=29144837 | doi-access=free }}</ref>

==Genetics==
The [[genome]] of ''Petromyzon marinus'' was sequenced in 2013.<ref name="SmithKuraku2013">{{cite journal|last1=Smith|first1=Jeramiah J|last2=Kuraku|first2=Shigehiro|last3=Holt|first3=Carson|last4=Sauka-Spengler|first4=Tatjana|last5=Jiang|first5=Ning|last6=Campbell|first6=Michael S|last7=Yandell|first7=Mark D|last8=Manousaki|first8=Tereza|last9=Meyer|first9=Axel|last10=Bloom|first10=Ona E|last11=Morgan|first11=Jennifer R|last12=Buxbaum|first12=Joseph D|last13=Sachidanandam|first13=Ravi|last14=Sims|first14=Carrie|last15=Garruss|first15=Alexander S|last16=Cook|first16=Malcolm|last17=Krumlauf|first17=Robb|last18=Wiedemann|first18=Leanne M|last19=Sower|first19=Stacia A|last20=Decatur|first20=Wayne A|last21=Hall|first21=Jeffrey A|last22=Amemiya|first22=Chris T|last23=Saha|first23=Nil R|last24=Buckley|first24=Katherine M|last25=Rast|first25=Jonathan P|last26=Das|first26=Sabyasachi|last27=Hirano|first27=Masayuki|last28=McCurley|first28=Nathanael|last29=Guo|first29=Peng|last30=Rohner|first30=Nicolas|last31=Tabin|first31=Clifford J|last32=Piccinelli|first32=Paul|last33=Elgar|first33=Greg|last34=Ruffier|first34=Magali|last35=Aken|first35=Bronwen L|last36=Searle|first36=Stephen M J|last37=Muffato|first37=Matthieu|last38=Pignatelli|first38=Miguel|last39=Herrero|first39=Javier|last40=Jones|first40=Matthew|last41=Brown|first41=C Titus|last42=Chung-Davidson|first42=Yu-Wen|last43=Nanlohy|first43=Kaben G|last44=Libants|first44=Scot V|last45=Yeh|first45=Chu-Yin|last46=McCauley|first46=David W|last47=Langeland|first47=James A|last48=Pancer|first48=Zeev|last49=Fritzsch|first49=Bernd|last50=de Jong|first50=Pieter J|last51=Zhu|first51=Baoli|last52=Fulton|first52=Lucinda L|last53=Theising|first53=Brenda|last54=Flicek|first54=Paul|last55=Bronner|first55=Marianne E|last56=Warren|first56=Wesley C|last57=Clifton|first57=Sandra W|last58=Wilson|first58=Richard K|last59=Li|first59=Weiming|title=Sequencing of the sea lamprey (''Petromyzon marinus'') genome provides insights into vertebrate evolution|journal=Nature Genetics|year=2013|doi=10.1038/ng.2568|pmid=23435085|volume=45|issue=4|pmc=3709584|pages=415–421}}</ref> This sequencing effort revealed that the lamprey has unusual [[guanine-cytosine content]] and amino acid usage patterns compared to other vertebrates. The full sequence and annotation of the [http://www.ensembl.org/Petromyzon_marinus/Info/Index/ lamprey genome] is available on the [[Ensembl]] genome browser.

The lamprey genome may serve as a model for developmental biology and evolution studies involving transposition of repetitive sequences. The lamprey genome undergoes drastic rearrangements during early embryogenesis in which about 20% of the germline DNA from somatic tissues is shed. The genome is highly repetitive. About 35% of the current genome assembly is composed of repetitive elements with high sequence identity.<ref name="SmithKuraku2013" /> Northern lampreys have the highest number of [[chromosome]]s (164–174) among vertebrates.<ref>{{FishBase family |family=Petromyzontidae |month=February |year=2011}}</ref>

Two genes important to immune function—CDA1 and CDA2—were first discovered in ''P.&nbsp;marinus'' and then found to be [[evolutionary conservation|conserved]] across lampreys. See [[#Immunology|§Immunology]] above.<ref name="Boehm-et-al-2018" />

==Invasive species==
Sea lampreys are considered a [[invasive species|pest]] in the [[Great Lakes region (North America)|Great Lakes region]]. Whether it is native to [[Lake Ontario]], where it was first noticed in the 1830s, or whether it was introduced through the [[Erie Canal]], which opened in 1825 was not clear as of 2007.<ref>[https://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=836 Nonindigenous Aquatic Species Factsheet: ''Petromyzon marinus''] {{Webarchive|url=https://web.archive.org/web/20090511075840/http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=836 |date=2009-05-11 }}. U.S. Geological Survey (USGS), Nonindigenous Aquatic Species Program (NAS). Retrieved on 2007-08-04.</ref> The species was first contained to Lake Ontario due to the natural barrier formed by [[Niagara Falls]]. However, after the [[Welland Canal]] was built in the late 1800s – early 1900s, they were able to bypass Niagara Falls and invade the remaining Great Lakes: Lakes [[Lake Erie|Erie]] (1921), [[Lake Michigan|Michigan]] (1936), [[Lake Huron|Huron]] (1937), and [[Lake Superior|Superior]] (1938), where it decimated indigenous fish populations in the 1930s and 1940s.<ref>{{Cite episode|title=May 3, 1949|date=May 3, 1949|station=WKZO|last=Dunbar|first=Willis|series=Western Michigan at Work|access-date=December 17, 2019|url=http://www.lib.msu.edu/uri-res/N2L?urn:x-msulib::vvl:DB37593|language=en}}</ref><ref name=":1" />

In its original habitats, the sea lamprey coevolved with its hosts, and those hosts evolved a measure of resistance to the sea lampreys. However, in the Great Lakes, the sea lamprey attacks native fish such as [[lake trout]], [[lake whitefish]], [[Freshwater whitefish|chub]], and [[Northern cisco|lake herring]], which historically did not face sea lampreys. Elimination of these predators allowed the [[alewife (fish)|alewife]], another invasive species, to explode in population, with adverse effects on many native fish species.

The lake trout plays a vital role in the Lake Superior ecosystem. The lake trout has traditionally been considered an [[apex predator]], which means that it has no predators. The sea lamprey is an aggressive predator by nature, which gives it a competitive advantage in a lake system where it has no predators and its prey lacks defenses against it. The sea lamprey played a large role in the destruction of the Lake Superior trout population. Lamprey introduction along with poor, unsustainable fishing practices caused the lake trout populations to decline drastically. The relationship between predators and prey in the Great Lakes ecosystem then became unbalanced.<ref>{{cite journal|last=McClelland|first=Edward|title=Great Lake Invaders|journal=E – the Environmental Magazine|year=2008|volume=19|issue=2|pages=10–11}}</ref> Each individual sea lamprey has the potential of killing 40 pounds of fish through its 12–18 month feeding period.<ref name=":1">{{Cite web |title=Sea Lamprey: A Great Lakes Invader |url=http://www.glfc.org/sea-lamprey.php |access-date=2024-07-04 |website=www.glfc.org}}</ref>

===Efforts at control===
[[File:Boca de lamprea.1 - Aquarium Finisterrae.JPG|thumb|right|Mouth of a sea lamprey, ''Petromyzon marinus'']] 
[[File:Sea lamprey (Petromyzon marinus) breathing 2 - Gijon Aquarium - 2015-07-02.webm|thumb|right|Video of the breathing of sea lamprey, Gijón Aquarium]]
Control efforts, including electric current and chemical [[lampricide]]s<ref name="Dunlop-et-al-2018">{{cite journal | last1=Dunlop | first1=Erin S. | last2=McLaughlin | first2=Rob | last3=Adams | first3=Jean V. | last4=Jones | first4=Michael | last5=Birceanu | first5=Oana | last6=Christie | first6=Mark R. | last7=Criger | first7=Lori A. | last8=Hinderer | first8=Julia L.M. | last9=Hollingworth | first9=Robert M. | last10=Johnson | first10=Nicholas S. | last11=Lantz | first11=Stephen R. | last12=Li | first12=Weiming | last13=Miller | first13=James | last14=Morrison | first14=Bruce J. | last15=Mota-Sanchez | first15=David | last16=Muir | first16=Andrew | last17=Sepúlveda | first17=Maria S. | last18=Steeves | first18=Todd | last19=Walter | first19=Lisa | last20=Westman | first20=Erin | last21=Wirgin | first21=Isaac | last22=Wilkie | first22=Michael P. | title=Rapid evolution meets invasive species control: the potential for pesticide resistance in sea lamprey | journal=[[Canadian Journal of Fisheries and Aquatic Sciences]] | publisher=[[National Research Council Canada]] | volume=75 | issue=1 | year=2018 | issn=0706-652X | doi=10.1139/cjfas-2017-0015 | pages=152–168| hdl=1807/78674 | hdl-access=free }}</ref> have met with varied success. The control programs are carried out under the [[Great Lakes Fishery Commission]], a joint Canada–U.S. body, specifically by the agents of the [[Fisheries and Oceans Canada]] and the [[United States Fish and Wildlife Service]].

Genetic researchers have mapped the sea lamprey's genome in the hope of finding out more about evolution; scientists trying to eliminate the Great Lakes problem are coordinating with these genetic scientists, hoping to find out more about its immune system and fitting it into its place in the [[phylogenetic tree]].

Researchers from [[Michigan State University]] have teamed up with others from the Universities of [[University of Minnesota|Minnesota]], [[University of Guelph|Guelph]], and [[University of Wisconsin|Wisconsin]], and others in a research effort into newly synthesized [[pheromone]]s. These are believed to have independent influences on the sea lamprey behavior. One group of pheromones serves a migratory function in that when they are made by larvae, they are thought to lure maturing adults into streams with suitable spawning habitat. Sex pheromones emitted from males are capable of luring females long distances to specific locations. These pheromones are both several different compounds thought to elicit different behaviors that collectively influence the lampreys to exhibit migratory or spawning behaviors. Scientists are trying to characterize the function of each pheromone, and each part of the molecules, to determine if they can be used in a targeted effort at environmentally friendly lamprey control. However, as of 2017, the most effective control measures still involve the application of [[TFM (piscicide)|(3-trifluoromethyl-4-nitrophenol)]], or TFM, a selective pesticide, into rivers.<ref name=fsheet>{{cite web|url=http://www.glfc.org/pubs/FACT_4.pdf|title=TFM fact sheet|website=glfc.org|access-date=8 April 2018}}</ref> {{As of|2018}} no [[lampricide resistance]] has been detected in the Great Lakes. Further research and combined use of multiple control methods are needed to forestall future development of resistance.<ref name="Dunlop-et-al-2018" />

Another technique used in the prevention of lamprey population growth is the use of barriers in major reproduction streams of high value to the lamprey. The purpose of the barriers is to block their upstream migration to reduce reproduction. The issue with these barriers is that other aquatic species are also inhibited by this barrier. Fish that use tributaries are impeded from traveling upstream to spawn. To account for this, barriers have been altered and designed to allow the passage of most fish species, but still impede others.<ref>{{cite journal|last1=Pratt|first1=T. C.|last2=O’Connor|first2=L. M.|last3=Hallett|first3=A. G.|title=Balancing Aquatic Habitat Fragmentation and Control of Invasive Species: Enhancing Selective Fish Passage at Sea Lamprey Control Barriers|journal=Transactions of the American Fisheries Society|volume=138|issue=3|year=2009|pages=652–65|doi=10.1577/t08-118.1|bibcode=2009TrAFS.138..652P }}</ref><ref>{{cite web|website=Indiana State Government|author=AIS - Aquatic Invasive Species|title=Sea lamprey|url=http://www.in.gov/dnr/files/SEA_LAMPREY1.pdf}}</ref>

====Restoration====
The intent of lamprey control programs is a safer habitat and a healthier population growth for vulnerable native fish species such as lake trout. The [[Connecticut Department of Energy and Environmental Protection]] (DEEP) has taken a different path to this same goal by introducing sea lampreys to freshwater rivers and lakes of the Connecticut River watershed, and providing easier access around dams and other barriers for the lampreys to reach spawning sites high upstream.<ref>{{cite web|url=https://blog.nature.org/science/2017/12/11/recovery-why-sea-lampreys-need-to-be-restored-and-killed/|title=Recovery: Why Sea Lampreys Need to Be Restored and Killed|date=11 December 2017|website=nature.org|access-date=8 April 2018}}</ref> After preying on larger fish at sea, the adult lampreys migrate up the rivers to spawn, whereupon they quickly die of natural causes and [[decomposition|decompose]], thus providing a food source for the native freshwater fish species.

== See also ==
*[[Lamprey pie]]

== References ==
{{Reflist|30em}}

== External links ==
{{Commons category|Petromyzon marinus}}
{{Wikispecies|Petromyzon marinus}}
* [https://www.invadingspecies.com/invaders/fish/sea-lamprey-2/ Invading Species.com] Ontario Ministry of Natural Resources and Ontario Federation of Anglers and Hunters
* [https://nas.er.usgs.gov/queries/greatlakes/FactSheet.aspx?SpeciesID=836&Potential=N&Type=1&HUCNumber=DHuron GLANSIS Species Fact Sheet], United States Geological Survey
* [https://www.invasivespeciesinfo.gov/profile/sea-lamprey Species Profile – Sea Lamprey (''Petromyzon marinus'')], National Invasive Species Information Center, [[United States National Agricultural Library]]. Lists general information and resources for Sea Lamprey.
* View the [http://www.ensembl.org/Petromyzon_marinus/Info/Index/ Lamprey genome] in [[Ensembl]].
* {{UCSC genomes|petMar2}}
* [https://books.google.com/books?id=ANkDAAAAMBAJ&dq=true&pg=PA159 "Battle of the Great Lakes"] by CleLand Van Dresser, ''Popular Mechanics'', February 1950, pp.&nbsp;159–161/244.
* {{SealifePhotos|101174}}

{{Petromyzontiformes}}
{{Taxonbar|from=Q385764}}
{{Authority control}}

[[Category:Petromyzontidae|sea lamprey]]
[[Category:Fish of the North Atlantic]]
[[Category:Fish of Europe]]
[[Category:Fish of North America]]
[[Category:Fish of the Great Lakes]]
[[Category:Fish of Canada]]
[[Category:Fish of the Eastern United States]]
[[Category:Fish of the Mediterranean Sea]]
[[Category:Parasitic vertebrates]]
[[Category:Fish described in 1758|sea lamprey]]
[[Category:Taxa named by Carl Linnaeus|sea lamprey]]
[[Category:Articles containing video clips]]
[[Category:Habitats Directive species]]