name = Lamprey
image_width = 250px
Sea lampreyfrom Sweden
phylum = Chordata
ordo = Petromyzontiformes
familia = Petromyzontidae
subdivision_ranks = Subfamilies'
Geotriinae Mordaciinae Petromyzontinae
A lamprey (sometimes also called lamprey eel) is a
jawless fishwith a toothed, funnel-like sucking mouth. While lampreys are well known for those species which bore into the flesh of other fish to suck their blood, these species make up the minority. In zoology, lampreys are often not considered to be true fishbecause of their vastly different morphology and physiology.
Lampreys live mostly in coastal and fresh waters, although at least one
species, "Geotria australis", probably travels significant distances in the open ocean, as evidenced by the lack of reproductive isolation between Australian and New Zealandpopulations, and the capture of a specimen in the Southern Oceanbetween Australia and Antarctica. They are found in most temperate regions except Africa. Their larvae have a low tolerance for high water temperatures, which is probably why they are not found in the tropics.
eels, in that they have no scales, an adult lamprey can range anywhere from 13 to 100 centimetres (5 to 40 inches) long. Lampreys have no paired fins, large eyes, one nostril on the top of the head, and seven gills on each side. The unique morphological characteristics of lampreys, such as their cartilaginous skeleton, mean that they are the sister taxon (see cladistics) of all living jawed vertebrates ( gnathostomes) and are not classified within the Vertebrata itself.Fact|date=July 2007 This is disputed by some, who place lampreys within Vertebrata. [cite book
last = Liem
first = Karel F.
coauthors = William E. Bemis, Warren F. Walker, Jr., Lance Grande
title = Functional Anatomy of the Vertebrates
publisher = Thomson: Brooks/Cole
date = 2001
location = The United States of America
pages = 50
isbn = 0-03-022369-5]
Hagfish, which superficially resemble lampreys, are the sister taxon of the lampreys and gnathostomes (a clade termed the Craniata).Fact|date=April 2007
Studies reported in "Nature" suggest that lampreys have a unique type of
immune systemwith parts that are unrelated to the antibodiesfound in mammals. They also have a very high tolerance to ironoverload, and have biochemical defenses to detoxify this metal.
Lampreys begin life as burrowing freshwater
larvae (ammocoetes). At this stage, they are toothless, have rudimentary eyes, and feed on microorganisms. This larval stage can last five to seven years and so was originally thought to be an independent organism. They transform into adults in a metamorphosis which is at least as radical as that seen in amphibians. It involves a radical rearrangement of internal organs, development of eyes and transformation from a mud-dwelling filter feeder into an efficient swimming parasite/ predatorthat typically moves to the sea. The adult feeds by attaching its mouth to a fish, secreting an anticoagulantto the host, and feeding on the bloodand tissues of the host. In most species this phase lasts about 18 months.
Some lampreys are landlocked and remain in fresh water, and some of these stop feeding when they leave the larval stage. The landlocked species are usually rather small. To reproduce, lampreys return to fresh water, build a nest, spawn (that is, females lay eggs, males excrete semen), then invariably die. In "Geotria australis", the time from ceasing to feed at sea to spawning can be up to 18 months.
fossils are rare because cartilagedoes not fossilize as readily as bone. The oldest known fossil lampreys were from Early Carboniferouslimestones, [From the Mississippian Mazon Creeklagerstätte and the Bear Gulch Limestonesequence.] laid down in marine sediments in North America: "Mayomyzon pieckoensis" and "Hardistiella montanensis".
In the 22 June 2006 issue of "Nature", Mee-mann Chang and colleagues reported on a fossil lamprey from the same Early
Cretaceous lagerstätten that have yielded feathered dinosaurs, in the Yixian Formationof Inner Mongolia. The new species, morphologically similar to Carboniferous and modern forms, was given the name " Mesomyzon mengae" ("Middle lamprey"). The exceedingly well-preserved fossil showed a well-developed sucking oral disk, a relatively long branchial apparatus showing branchial basket, seven gill pouches, gill arches and even the impressions of gill filaments, and about 80 myomeres of its musculature.
Months later, in the 27 October issue of "Nature", an even older fossil lamprey, dated 360 million years ago, was reported from Witteberg Group rocks near Grahamstown, in the Eastern Cape of
South Africa. This species, dubbed "Priscomyzon riniensis" still strongly resembled modern lampreys despite its Devonianage. [cite web |url=http://web.wits.ac.za/NewsRoom/NewsItems/Lamprey.htm |title=Discovery of the Oldest Fossil Lamprey in the World |date=2006-10-26 |accessdate=2008-06-08 |publisher=University of the Witwatersrand]
The taxonomy presented here is that given by Fisher, 1994. This work classifies lampreys as the sole living members of the class
Cephalaspidomorphi. [Cephalaspidomorpha is sometimes given as a subclass of the Cephalaspidomorphi.] The lampreys entail the single order Petromyzontiformes and family Petromyzontidae. [Petromyzoniformes and Petromyzonidae are sometimes used as alternative spellings for Petromyzontiformes and Petromyzontidae respectively.]
Within this family, there are 40 recorded
speciesin nine genera and three subfamilies:
** Genus "
Pouched lamprey, " Geotria australis" (Gray,1851)
** Genus "
Mordacia lapicida" (Gray, 1851)
Mordacia mordax" (Richardson, 1846)
Mordacia praecox" (Potter, 1968)
** Genus "
Caspiomyzon wagneri" (Kessler, 1870)
** Genus "
Eudontomyzon danfordi" (Regan, 1911)
Eudontomyzon hellenicus" (Vladykov, Renaud, Kott and Economidis, 1982)
Eudontomyzon mariae" (Berg, 1931)
Eudontomyzon morii" (Berg, 1931)
Eudontomyzon stankokaramani" (Karaman, 1974)
Eudontomyzon vladykovi" (Oliva and Zanandrea, 1959)
** Genus "
Ichthyomyzon bdellium" (Jordan, 1885) - Ohio lamprey
Ichthyomyzon castaneus" Girard, 1858 - chestnut lamprey
Ichthyomyzon fossor" (Reighard and Cummins, 1916) - northern brook lamprey
Ichthyomyzon gagei" (Hubbs and Trautman, 1937) - southern brook lamprey
Ichthyomyzon greeleyi" (Hubbs and Trautman, 1937) - mountain brook lamprey
Ichthyomyzon unicuspis" (Hubbs and Trautman, 1937) - silver lamprey
** Genus "
Lampetra aepyptera" (Abbott, 1860) - least brook lamprey
Lampetra alaskensis" (Vladykov and Kott, 1978)
Lampetra appendix" (DeKay, 1842) - American brook lamprey
Lampetra ayresii" (Günther, 1870)
Lampetra fluviatilis" (Linnaeus, 1758)
Lampetra hubbsi" (Vladykov and Kott, 1976) - Kern brook lamprey
Lampetra lamottei" (Lesueur, 1827)
Lampetra lanceolata" (Kux and Steiner, 1972)
Lampetra lethophaga" (Hubbs, 1971) - Pit-Klamath brook lamprey
Lampetra macrostoma" (Beamish, 1982) - Vancouver lamprey
Lampetra minima" (Bond and Kan, 1973) - Miller Lake lamprey
Lampetra planeri" (Bloch, 1784)
Lampetra richardsoni" (Vladykov and Follett, 1965) - western brook lamprey
Lampetra similis" (Vladykov and Kott, 1979) - Klamath lamprey
Lampetra tridentata" (Richardson, 1836) - Pacific lamprey
** Genus "
Lethenteron camtschaticum" (Tilesius, 1811)
Lethenteron japonicum" (Martens, 1868)
Lethenteron kessleri" (Anikin, 1905)
Lethenteron matsubarai" (Vladykov and Kott, 1978)
Lethenteron reissneri" (Dybowski, 1869)
Lethenteron zanandreai" (Vladykov, 1955)
** Genus "
Petromyzon marinus" (Linnaeus, 1758) - sea lamprey
** Genus "
Tetrapleurodon geminis" (Alvarez, 1964)
Tetrapleurodon spadiceus" (Bean, 1887)
Some taxonomists place lampreys and hagfish in the
phylum Chordataunder the super-class Agnathostomata(without jaws). The other super-class of the phylum is Gnathostomata(jaw-having) and includes the classes Chondrichthyes, Osteichthyes, Amphibia, Reptila, Aves, and Mammalia.
Relation to humans
Lampreys have long been used as
foodfor humans. During the Middle Ages, they were widely eaten by the upper classes throughout Europe, especially during fastingperiods, since their taste is much meatier than that of most true fish. King Henry I of Englandis said to have died from eating "a surfeit of lampreys". [cite web |url=http://www.time.com/time/magazine/article/0,9171,861450,00.html |title=A Surfeit of Lampreys |publisher=Time |date=1955-05-09 |accessdate=2008-06-07] On 4th March 1953, the Queen of the United Kingdom's coronation pie was made by the Royal Air Force using lampreys.Fact|date=June 2008
Especially in southwestern Europe (
Portugal, Spain, and France), larger lampreys are still a highly prized delicacy. Overfishing has reduced their number in those parts. Lampreys are also consumed in Sweden, Finland, the Baltic countries, and South Korea.
In Britain, lampreys are commonly used as bait, normally as dead bait. Pike, perch and chub all can be caught on lampreys. Lampreys can be bought frozen from most bait and tackle shops.
Lampreys are used as a
model organismin biomedical research where their large reticulospinal axons are used to investigate synaptic transmission [Giant reticulospinal synapse in lamprey: molecular links between active and periactive zones., Brodin L. et al., Cell Tissue Res. 2006] . The axons of lamprey are particularly large and allow for microinjectionof substances for experimental manipulation.
Sea lampreys have become a major plague in the North American
Great Lakesafter artificial canalsallowed their entry during the early 20th century. They are considered an invasive species, have no natural enemies in the lakes and prey on many species of commercial value, such as lake trout. Since the majority of North American consumers, unlike Europeans, refuse to accept lampreys as food, the Great Lakes fishery has been adversely affected by their invasion. Lampreys are now found mostly in the streams that feed the lakes, with special barriers to prevent the upstream movement of adults, or by the application of toxicants called lampricides, which are harmless to most other aquatic species. However those programs are complicated and expensive, and do not eradicate the lampreys from the lakes but merely keep them in check. New programs are being developed including the use of chemically sterilized male lamprey in a method akin to the sterile insect technique. Research is currently under way on the use of pheromonesand how they may be used to disrupt the life cycle (Sorensen, "et al.", 2005). Control of sea lampreys in the Great Lakes is conducted by the U.S. Fish and Wildlife Serviceand the Canadian Department of Fisheries and Oceans. The work is coordinated by the Great Lakes Fishery Commission. Lake Champlain, bordered by New York State, Vermont, and Quebec, and New York's Finger Lakesare also home to populations of sea lampreys whose high populations have warranted control. Lake Champlain's lamprey control program is managed by the New York State Department of Environmental Conservation, the Vermont Department of Fish and Wildlife, and the U.S. Fish and Wildlife Service. New York's Finger Lakes sea lamprey control program is managed solely by the New York State Department of Environmental Conservation.
Vedius Polliowas punished by Augustusfor attempting to feed a clumsy slaveto the lampreys in his fishpond.
:...one of his slaves had broken a crystal cup. Vedius ordered him to be seized and to be put to death in an unusual way. He ordered him to be thrown to the huge lampreys which he had in his fish pond. Who would not think he did this for display? Yet it was out of cruelty. The boy slipped from the captor’s hands and fled to Caesar’s feet asking nothing else other than a different way to die—he did not want to be eaten. Caesar was moved by the novelty of the cruelty and ordered him to be released, all the crystal cups to be broken before his eyes, and the fish pond to be filled in... – Seneca," On Anger", III, 40 [http://home.triad.rr.com/warfford/Roman_Empire/slavery.html]
Christopher Warner, a character in
Philip Larkin's early novel "Jill" is said to have attended a fictional minor public school called Lamprey College.
Lamprey pies are an appreciated dish often referred in
George R.R. Martin's popular fantasy series " A Song of Ice and Fire"
Stephen King's novel
Dreamcatcherhas alien cratures that look and move like Lampreys, which are nicknamed in the novel, "shitweasles"
* [http://www.itis.usda.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=159697 ITIS report on the lampreys]
* [http://www.cfb.ie/fisheries_research/lamprey/index.htm "Lamprey conservation"]
* [http://www.tellapallet.com/tree_of_life.htm A Tree of Life diagram showing the relation of Lampreys to other organisms]
* [http://www.sciencenews.org/pages/sn_arch/8_10_96/food.htm Lampreys as food, including recipes]
* [http://scienceblogs.com/pharyngula/2006/02/lamprey_skeletons.php#more Lamprey skeletons]
* [http://english.pravda.ru/news/science/27-10-2006/85250-lamprey-0 "Scientists from South Africa discover world's oldest fish fossil"] News report on 27 October 2006 "Nature" article.
* [http://www.guardian.co.uk/science/story/0,,1803115,00.html Alok Jha, Perfect lampreys show little change in 125 m years "The Guardian" (22 June 2006)]
* [http://www.uchospitals.edu/news/2006/20061026-lamprey.html Scientists find lamprey a 'living fossil']
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