Sea Lamprey (Petromyzon marinus)
FishJawless FishAnadromous
A sea lamprey in a shallow stream in New York State during the spawning season.
Image: Stephanie Tran, CC BY 4.0, via Wikimedia Commons.
Overview
The sea lamprey (Petromyzon marinus) is a jawless, eel-like fish native to the Atlantic coasts and rivers of North America and Europe. Its larvae spend years buried in stream beds before transforming into parasites that feed on the blood of other fish, and it has invaded the Great Lakes above Niagara Falls.
It has a scaleless, cartilaginous body with two dorsal fins and no paired fins, seven gill openings behind each eye, and a round sucking mouth lined with circular rows of sharp teeth around a file-like rasping tongue. It is mottled olive or brown-yellow to dark brown or black above and paler below; breeding males develop a rope-like ridge on the back, and the blind, worm-like larvae are called ammocoetes.
Sea-run adults reach up to 120 cm and 2.5 kg, and one account says most individuals attain 60–75 cm. Landlocked adults are smaller: at most 60 cm in the Great Lakes by one account and 64 cm by another, rarely more than 64 cm by a third, and rarely over 0.6 kg.
Habitat & Range
Sea-run lampreys feed in estuaries, coastal waters and the open ocean — at sea both in open water and near the bottom, possibly to a depth of 4,099 m — and spawn in rivers over clean gravel in shallow, swift riffles; the larvae burrow in silt or sand in slow stretches of streams. Landlocked populations feed in lakes and large rivers.
The native range runs along the Atlantic coast of North America from Labrador or Newfoundland to Florida, and along the coasts of Europe, including the Baltic, the Adriatic and the western Mediterranean; it has also been recorded from Greenland, Iceland and the Barents and White seas south to northern Morocco, is absent from the eastern Mediterranean and is extinct in or absent from the Black Sea. Landlocked populations live in the Great Lakes, the Finger Lakes, Oneida Lake and Lake Champlain, and whether some of these are native or arrived through canals is disputed.
Diet
Larvae filter-feed in the stream bed on diatoms and detritus. The parasitic stage attaches to a fish — or, at sea, to a cetacean — rasps through its scales and skin, and feeds on its blood and body fluids — and, by one account, flesh — helped by an anticoagulant, although one study found blood made up almost the entire diet. Hosts range from lake trout, whitefish, sturgeon and salmon in the Great Lakes to cod, herring, mackerel, swordfish and basking sharks in the Atlantic.
In the native Atlantic, hosts typically survive, but most Great Lakes fish attacked by a sea lamprey die.
Behavior
Sea lampreys avoid light at several life stages and are mostly nocturnal as burrowing larvae and as migrating adults. Newly transformed juveniles migrate downstream to open water from fall through spring, and in one set of field studies they did so mainly at night. Sea-run fish then feed at sea, moving farther offshore as they grow, before migrating upriver to spawn — a journey that may cover 20–850 km — finding spawning streams by pheromones released by the larvae living there.
Landlocked lampreys move between streams and lakes instead, and their feeding migrations in the Great Lakes can reach 628 km.
Human Interaction & Conservation
Sea lampreys reached the upper Great Lakes after a major renovation of the Welland Canal let ships bypass Niagara Falls, which had been a natural barrier, and fed heavily on lake trout, whitefish and ciscoes: the upper lakes' lake trout catch fell from about 15 million pounds a year to about 300,000 pounds by the early 1960s. Since 1956 a binational control program run by the Great Lakes Fishery Commission has used chemicals that kill lamprey larvae, barriers and traps, cutting numbers by more than 90%.
In a large part of its native range, by contrast, the sea lamprey is threatened or endangered; in the UK it is an Annex II species, for which a series of Special Areas of Conservation has been selected. It has been fished and eaten in Europe for centuries, though high mercury levels make landlocked adults unsuitable to eat. IUCN's global assessment lists the sea lamprey as Least Concern (2024).
Reproduction & Life Cycle
Sea lampreys spawn once and die. Adults run upriver in spring and early summer, when the water is 10–18 °C, and spawn mostly on sunny days in water of at least 15 °C. Males build a nest (redd) in a shallow, swift, rocky riffle, moving stones one at a time with the sucking disc, and females help or build their own nests later in the season; up to ten lampreys have been found in one nest.
Females produce 43,997–101,932 eggs in landlocked populations and 151,836–304,832 in sea-run ones. Females leave the nest right after spawning and drift into pools, where they die, while males may stay in the nest for one to three days. The larvae emerge 11 to 31 days after spawning and settle into soft stream-bed sediment.
The whole life cycle usually takes 5 to 9 years in the Great Lakes region, though another account gives 1.5 to 5 years. The larval stage is given as three to ten-plus years in Great Lakes streams, 3–17 years, about four to 17 years, or usually at least 5 years (2 to 19 or more), and the parasitic stage as 12 to 18 or 12 to 20 months in the Great Lakes and about 20–36 months at sea. One database gives a maximum reported age of 11 years, shorter than some of the larval durations reported elsewhere.
Sourced facts
Each value below is traced to the specific reference that states it. Open a row's evidence to see the source, where to look in it, and how firmly it supports the value. Sources checked 2026-10-20.
| Fact | What the source states | Evidence |
|---|---|---|
| Distinguishing traits | Eel-like, scaleless, jawless and cartilaginous; the round sucking mouth has circular rows of sharp teeth and a file-like rasping tongue. Seven gill openings behind each eye; two dorsal fins, no paired fins. Mottled olive or brown-yellow to dark brown or black above, paler below.Its much larger size and distinctly mottled pattern set it apart from the river lamprey and brook lamprey. Breeding males develop a rope-like ridge on the back. Larvae (ammocoetes) are blind and worm-like; newly transformed juveniles are grayish blue above, grading to white on the belly. | Matches source · U.S. Geological Survey, Nonindigenous Aquatic Species Database, FishBase (Froese & Pauly, eds.), Marine Life Information Network (MarLIN), Marine Biological Association of the UK, U.S. Fish and Wildlife Service, Fisheries and Oceans Canada — how we knowU.S. Geological Survey, Nonindigenous Aquatic Species Database
FishBase (Froese & Pauly, eds.)
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
U.S. Fish and Wildlife Service
Fisheries and Oceans Canada
|
| Geographic range | Native to Atlantic coasts and rivers of North America (from Labrador, Newfoundland or the Gulf of St. Lawrence south to Florida) and Europe, including the Baltic, Adriatic and western Mediterranean seas. Invasive in the Great Lakes above Niagara Falls.sources disagreeAlso recorded from Greenland, Iceland, the Barents and White seas and south to northern Morocco; extinct in or absent from the Black Sea, and absent from the eastern Mediterranean. It had entered Lake Erie by 1921 and then spread through the upper lakes. Landlocked populations live in the Great Lakes, Finger Lakes, Oneida Lake and Lake Champlain. | Sources disagree · Fisheries and Oceans Canada, U.S. Geological Survey, Nonindigenous Aquatic Species Database, FishBase (Froese & Pauly, eds.), California Academy of Sciences (Eschmeyer's Catalog of Fishes), Government of Ontario (Ministry of Natural Resources), Ontario Freshwater Fishes Life History Database, U.S. Fish and Wildlife Service, NOAA Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS), hosted on the USGS NAS site — how we knowWhat each reading says
Western Atlantic limits differ (Labrador, Newfoundland and Labrador, Newfoundland or the Gulf of St. Lawrence, south to Florida, northern Florida, the St. Johns River or the Gulf of Mexico), and accounts disagree on whether the populations of Lake Ontario, the Finger Lakes and Lake Champlain are native or arrived through canals in the 1800s. Fisheries and Oceans Canada
U.S. Geological Survey, Nonindigenous Aquatic Species Database
FishBase (Froese & Pauly, eds.)
California Academy of Sciences (Eschmeyer's Catalog of Fishes)
Government of Ontario (Ministry of Natural Resources)
Ontario Freshwater Fishes Life History Database
U.S. Fish and Wildlife Service
NOAA Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS), hosted on the USGS NAS site
|
| Habitat | Sea-run fish feed in estuaries, coastal waters and the open ocean, and spawn in rivers over clean gravel in shallow, swift riffles; larvae burrow in silt or sand in slow stream stretches. Landlocked populations feed in lakes and large rivers.At sea it occurs both in open water and near the bottom, possibly to a depth of 4,099 m. In Britain it uses estuaries and easily accessible rivers, prefers warm water for spawning and seems to be relatively poor at passing obstacles and is frequently restricted to the lower reaches of rivers. Spawning adults also occur in creeks or lake inlets. | Matches source · FishBase (Froese & Pauly, eds.), U.S. Geological Survey, Nonindigenous Aquatic Species Database, Joint Nature Conservation Committee (UK) — how we knowFishBase (Froese & Pauly, eds.)
U.S. Geological Survey, Nonindigenous Aquatic Species Database
Joint Nature Conservation Committee (UK)
|
| Diet | Larvae filter-feed in stream beds on diatoms and detritus. The parasitic stage attaches to fish (and to cetaceans at sea), rasps through scales and skin, and feeds on blood and body fluids, and also flesh by one account, aided by an anticoagulant; it stops feeding before spawning.Blood made up almost all of the diet in one study. Any fish with enough room to attach can serve as a host: lake trout, whitefish, ciscoes, sturgeon, burbot, walleye and salmonids in the Great Lakes; cod, haddock, herring, mackerel, swordfish, sturgeons and basking sharks in the Atlantic. In the native Atlantic hosts typically survive, but most Great Lakes fish it attacks die. | Matches source · FishBase (Froese & Pauly, eds.), U.S. Fish and Wildlife Service, Great Lakes Fishery Commission — how we knowFishBase (Froese & Pauly, eds.)
U.S. Fish and Wildlife Service
Great Lakes Fishery Commission
Great Lakes Fishery Commission
Great Lakes Fishery Commission
|
| Body size | Sea-run adults: up to 120 cm. Most individuals attain 60–75 cm (form not stated). Landlocked adults: up to 60 cm TL in the Laurentian Great Lakes or 64 cm, and rarely over 64 cm. Larvae: up to 5 inches, 18 cm or 200 mm.sources disagreeCommon length 60.0 cm TL. The 120 cm maximum is a total length in one account that names no form; two others give it for marine or anadromous fish. Other adult ranges given: 305–610 mm and 14 to 24 inches (form not stated), 30.2–58.1 cm TL in Ontario, and about a metre in Ireland. | Sources disagree · FishBase (Froese & Pauly, eds.), Fisheries and Oceans Canada, U.S. Geological Survey, Nonindigenous Aquatic Species Database, Government of Ontario (Ministry of Natural Resources), U.S. Fish and Wildlife Service, Ontario Freshwater Fishes Life History Database, Inland Fisheries Ireland — how we knowWhat each reading says
The maximum length of landlocked adults is 60 cm TL in the Great Lakes in one account and 64 cm in another, while a third says they rarely exceed 64 cm; and the larval maximum is 5 inches, 18 cm or 200 mm depending on the account; typical adult lengths also differ among accounts. FishBase (Froese & Pauly, eds.)
Fisheries and Oceans Canada
U.S. Geological Survey, Nonindigenous Aquatic Species Database
Government of Ontario (Ministry of Natural Resources)
U.S. Fish and Wildlife Service
Ontario Freshwater Fishes Life History Database
Inland Fisheries Ireland
|
| Body mass | Sea-run (marine) adults: up to 2.5 kg. Landlocked adults rarely exceed 0.6 kg.A 120 cm specimen weighed 2.3 kg. Sea-run juveniles grow from about 4 g to 900 g over a 23–28-month feeding period in estuaries and coastal waters. Adults in Ontario weigh 0.07–0.37 kg. | Matches source · Fisheries and Oceans Canada, FishBase (Froese & Pauly, eds.), Ontario Freshwater Fishes Life History Database — how we knowFisheries and Oceans Canada
FishBase (Froese & Pauly, eds.)
Ontario Freshwater Fishes Life History Database
|
| Lifespan | Wild: the whole life cycle usually takes 5 to 9 years (Great Lakes region), or 1.5 to 5 years; maximum reported age 11 years. Larvae spend several years burrowed in stream beds, and adults die after spawning once.sources disagreeLarval stage: three to ten-plus years in Great Lakes streams, 3–17 years, about four to 17 years, or usually at least 5 years (2 to 19 or more); about six to eight years in Ireland. Parasitic stage: 12 to 18 or 12 to 20 months in the Great Lakes; about 20–36 months at sea, or up to three years in Ireland. No captive lifespan is reported. | Sources disagree · Government of Ontario (Ministry of Natural Resources), Ontario Freshwater Fishes Life History Database, Animal Diversity Web (University of Michigan Museum of Zoology), FishBase (Froese & Pauly, eds.), Great Lakes Fishery Commission, U.S. Geological Survey, Nonindigenous Aquatic Species Database, U.S. Fish and Wildlife Service, Inland Fisheries Ireland — how we knowWhat each reading says
Typical lifespan is five to 9 (5-9) years in two accounts but 1.5 to 5 years in another, which also says the life cycle usually spans 18 months, shorter than the larval stage alone in other accounts; a maximum reported age of 11 years in one database is likewise shorter than several reported larval durations (up to 17, or 19 or more, years). Larval and parasitic stage durations also differ among accounts. Government of Ontario (Ministry of Natural Resources)
Ontario Freshwater Fishes Life History Database
Animal Diversity Web (University of Michigan Museum of Zoology)
FishBase (Froese & Pauly, eds.)
Great Lakes Fishery Commission
U.S. Geological Survey, Nonindigenous Aquatic Species Database
U.S. Fish and Wildlife Service
Inland Fisheries Ireland
|
| Activity pattern | Mostly nocturnal as burrowing larvae and as migrating adults, avoiding light at several life stages. Newly transformed juveniles migrate downstream from fall through spring, mainly at night in one set of field studies. Adults run upriver in spring and early summer and spawn mostly on sunny days.In the Great Lakes, feeding stops in winter or early spring, when juveniles begin seeking spawning streams. Upriver runs occur at water temperatures of 10–18°C, and spawning at 15°C or more. | Matches source · PLOS ONE (Miehls, Holbrook & Marsden 2019; USGS Great Lakes Science Center and University of Vermont), FishBase (Froese & Pauly, eds.), Great Lakes Fishery Commission — how we knowPLOS ONE (Miehls, Holbrook & Marsden 2019; USGS Great Lakes Science Center and University of Vermont)
FishBase (Froese & Pauly, eds.)
Great Lakes Fishery Commission
|
| Reproduction | Semelparous: spawns once, in spring or early summer, then dies. Males build a nest (redd) in shallow, swift, rocky riffles, moving stones one at a time with the sucking disc; females help or build nests later in the season.Fecundity: 43,997–101,932 eggs per female in landlocked populations, 151,836–304,832 in sea-run ones. Larvae emerge from the nest 11 to 31 days after spawning. Up to ten lampreys have been found in one nest. Females leave the nest immediately after spawning and drift into pools, where they die; males may stay in the nest one to three days. | Matches source · FishBase (Froese & Pauly, eds.), U.S. Fish and Wildlife Service, Great Lakes Fishery Commission, U.S. Geological Survey, Nonindigenous Aquatic Species Database — how we knowFishBase (Froese & Pauly, eds.)
U.S. Fish and Wildlife Service
Great Lakes Fishery Commission
U.S. Geological Survey, Nonindigenous Aquatic Species Database
|
| Movement | Anadromous: transformed juveniles go downstream to the sea, feed there while moving farther offshore as they grow, then migrate upriver to spawn, a journey that may cover 20–850 km inland, locating spawning streams by pheromones from larvae. Landlocked populations move between streams and lakes.In one study, most downstream movement occurred during floods in March, April and May. Feeding migrations of landlocked Great Lakes adults can reach 628 km. Some Irish lakes hold landlocked sea lampreys, smaller than sea-run ones, that appear not to migrate to sea. | Matches source · FishBase (Froese & Pauly, eds.), U.S. Geological Survey, Nonindigenous Aquatic Species Database, U.S. Fish and Wildlife Service, Great Lakes Fishery Commission, Fisheries and Oceans Canada, Inland Fisheries Ireland — how we knowFishBase (Froese & Pauly, eds.)
U.S. Geological Survey, Nonindigenous Aquatic Species Database
U.S. Fish and Wildlife Service
Great Lakes Fishery Commission
Fisheries and Oceans Canada
Inland Fisheries Ireland
|
| Human interaction | Invaded the upper Great Lakes after a major renovation of the Welland Canal let ships bypass Niagara Falls, devastating lake trout, whitefish and cisco fisheries; binational control since 1956, with larva-killing chemicals, barriers and traps, has cut numbers by more than 90%.Upper Great Lakes lake trout harvests fell from about 15 million pounds a year to about 300,000 pounds by the early 1960s. Niagara Falls had been a natural barrier. The control program is administered by the Great Lakes Fishery Commission. Threatened or endangered in a large part of its native range; in the UK an Annex II species, for which a series of Special Areas of Conservation has been selected. It has been fished and eaten in Europe for centuries; high mercury levels preclude eating landlocked adults. | Matches source · Great Lakes Fishery Commission, U.S. Fish and Wildlife Service, Fisheries and Oceans Canada, Government of Ontario (Ministry of Natural Resources), FishBase (Froese & Pauly, eds.), Animal Diversity Web (University of Michigan Museum of Zoology), PLOS ONE (Miehls, Holbrook & Marsden 2019; USGS Great Lakes Science Center and University of Vermont), Joint Nature Conservation Committee (UK) — how we knowGreat Lakes Fishery Commission
U.S. Fish and Wildlife Service
Fisheries and Oceans Canada
Government of Ontario (Ministry of Natural Resources)
Great Lakes Fishery Commission
FishBase (Froese & Pauly, eds.)
Animal Diversity Web (University of Michigan Museum of Zoology)
PLOS ONE (Miehls, Holbrook & Marsden 2019; USGS Great Lakes Science Center and University of Vermont)
Joint Nature Conservation Committee (UK)
|
| Conservation status | Least Concern (LC), global assessment, 2024 | Matches source · IUCN Red List of Threatened Species — how we knowIUCN Red List of Threatened Species
|
References for the facts above
- ReferenceCalifornia Academy of Sciences (Eschmeyer's Catalog of Fishes)Supports: identity (accepted name, synonyms); range (distribution summary). Retrieved 2026-10-20.Limitations: Taxonomic catalogue (online version updated 21 Sep. 2026); distribution is a one-line summary and does not separate native from introduced occurrence.
- ReferenceFishBase (Froese & Pauly, eds.)Supports: identification, range, habitat, diet, body-size, weight, lifespan, activity, reproduction, movement, human-interaction. Retrieved 2026-10-20.Limitations: Compiled summary (page last modified 20 July 2016) drawing on Renaud (2011), Hardisty (1986) and others; its 120 cm maximum length and 11-year maximum age are not tied to a form; its 60 cm TL landlocked maximum differs from the 64 cm in two other accounts; it gives hatching after 7-14 days (not used, see notes); 'Threat to humans: Harmless' and reports of intoxication from eating the species were not used.
- GovernmentU.S. Geological Survey, Nonindigenous Aquatic Species DatabaseSupports: identification, range, habitat, body-size, lifespan, reproduction, movement. Retrieved 2026-10-20.Limitations: Fact sheet focused on Great Lakes introductions (revision date 7/10/2026). In this version 'Lake Ontario' appears as 'Lake America' throughout the body text (reference titles still read 'Lake Ontario'), so passages naming that lake were not used. Its juvenile and adult lengths (6 to 24 and 14 to 24 inches) do not say which form they describe.
- GovernmentNOAA Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS), hosted on the USGS NAS siteSupports: range (status of the Finger Lakes and Lake Champlain populations). Retrieved 2026-10-20.Limitations: Great Lakes profile sharing much text with the USGS fact sheet, including the same 'Lake America' substitution; used only for one statement on the Finger Lakes and Lake Champlain. Its first Lake Superior record (1946) differs from the 1938 date given by the Great Lakes Fishery Commission (see notes).
- UniversityAnimal Diversity Web (University of Michigan Museum of Zoology)Supports: lifespan (conflicting reading); human-interaction (European consumption). Retrieved 2026-10-20.Limitations: Student-written account (2011, last updated 2011-02-13) headed 'Eel sucker'. Several statements are contradicted by the other sources and were not used: seasonal coastal migrations to Africa and India and a native 'oriental' range, depths of 0.91 to 4.57 m, a lack of vertebrae and of a lateral line, 'groups or colonies' on hosts, hatching in 3 to 8 weeks, a larval phase of 1 to 3 years, and consumption 'in Asia and India'.
- GovernmentGreat Lakes Fishery CommissionSupports: diet, human-interaction. Retrieved 2026-10-20.Limitations: Overview page of the binational commission that runs the Great Lakes control program; Great Lakes focus. Not used: its dates for Lakes Michigan, Huron and Superior (1936, 1937, 1938; another account gives 1946 for Lake Superior) and its 'up to 40 pounds (more than 20 kilograms)' killed per lamprey (other accounts give other figures; see notes).
- GovernmentGreat Lakes Fishery CommissionSupports: diet, lifespan, activity, reproduction, movement. Retrieved 2026-10-20.Limitations: Short life-cycle summary for Great Lakes populations; durations written in words.
- GovernmentGreat Lakes Fishery CommissionSupports: diet, human-interaction. Retrieved 2026-10-20.Limitations: Short page on fishery impacts and control results; Great Lakes focus.
- GovernmentFisheries and Oceans CanadaSupports: identification, range, body-size, weight, movement, human-interaction. Retrieved 2026-10-20.Limitations: Brief aquatic invasive species identification page (date modified 2018-05-04).
- GovernmentGovernment of Ontario (Ministry of Natural Resources)Supports: range, body-size, lifespan, human-interaction. Retrieved 2026-10-20.Limitations: Invasive species fact sheet (updated June 11, 2026) about Great Lakes populations; its advice to the public was not used, nor its adult length of 30 to 76 cm, which exceeds the landlocked maximum given elsewhere.
- GovernmentU.S. Fish and Wildlife ServiceSupports: identification, range, diet, body-size, lifespan, reproduction, movement, human-interaction. Retrieved 2026-10-20.Limitations: Species profile citing mostly older literature (Applegate 1950 and others); its size figures do not say which form they describe; it dates the first Lake Superior record to 1946.
- GovernmentJoint Nature Conservation Committee (UK)Supports: habitat, human-interaction. Retrieved 2026-10-20.Limitations: UK Special Areas of Conservation species account; UK and European focus, no figures.
- GovernmentInland Fisheries IrelandSupports: body-size, lifespan, movement. Retrieved 2026-10-20.Limitations: Short species page for Ireland; figures are rounded ('about a metre', 'about six to eight years'); the URL redirects to /fish-species/sea-lamprey-petromyzon-marinus.
- ReferenceMarine Life Information Network (MarLIN), Marine Biological Association of the UKSupports: identification. Retrieved 2026-10-20.Limitations: Basic information review for the British Isles (Barnes 2008, last updated 27/03/2008); its 'August' spawning run was not used.
- ReferenceOntario Freshwater Fishes Life History DatabaseSupports: range, body-size, weight, lifespan. Retrieved 2026-10-20.Limitations: Compiled database of life-history values for Ontario with a reference list; values are not attributed to individual references; its fecundity range (13,974-107,138) differs from FishBase's landlocked range and was not used.
- ReferencePLOS ONE (Miehls, Holbrook & Marsden 2019; USGS Great Lakes Science Center and University of Vermont)Supports: activity, human-interaction. Retrieved 2026-10-20.Limitations: Peer-reviewed field study of newly transformed juveniles in Michigan streams (PLOS ONE 14(2): e0211687), read on the publisher's site; its statement that larvae and migrating adults are mostly nocturnal cites earlier work.
- ReferenceIUCN Red List of Threatened SpeciesSupports: The global Red List category and the year of the assessment. Retrieved 2026-10-20.Limitations: Read from the Red List export IUCN publishes to GBIF; iucnredlist.org itself does not answer automated reads. Categories are reassessed over time.
Frequently Asked Questions — Sea Lamprey
Is the sea lamprey a fish?
Yes, a jawless one. It has a cartilaginous skeleton, no scales, no paired fins and no jaws — instead, a round sucking mouth lined with sharp teeth.
How does a sea lamprey feed?
The parasitic stage attaches to a fish with its sucking mouth, rasps through the scales and skin with its file-like tongue, and feeds on blood and body fluids, helped by an anticoagulant. In the Great Lakes, most fish it attacks die.
Why are sea lampreys a problem in the Great Lakes?
They invaded the upper lakes after a major renovation of the Welland Canal let ships bypass Niagara Falls, and fed heavily on lake trout, whose catch fell from about 15 million pounds a year to about 300,000 pounds by the early 1960s. A control program since 1956 has cut their numbers by more than 90%.
How long do sea lampreys live?
The life cycle usually takes 5 to 9 years in the Great Lakes region, with several years spent as a larva buried in a stream bed; another account gives 1.5 to 5 years. Adults spawn once and die.
Sources and further reading
Authoritative wildlife references used for general educational context. Conservation status should always be verified against current IUCN Red List data. External links open in a new tab.
- ReferenceCalifornia Academy of Sciences (Eschmeyer's Catalog of Fishes) — Petromyzon marinus, Eschmeyer's Catalog of Fishes — identity (accepted name, synonyms); range (distribution summary)
- ReferenceIntegrated Taxonomic Information System (ITIS) — Petromyzon marinus, TSN 159722 — identity (hierarchy, authorship, common names)
- ReferenceFishBase (Froese & Pauly, eds.) — Petromyzon marinus species summary — identification, range, habitat, diet, body-size, weight, lifespan, activity, reproduction, movement, human-interaction
- GovernmentU.S. Geological Survey, Nonindigenous Aquatic Species Database — Sea lamprey, Nonindigenous Aquatic Species fact sheet — identification, range, habitat, body-size, lifespan, reproduction, movement
- GovernmentNOAA Great Lakes Aquatic Nonindigenous Species Information System (GLANSIS), hosted on the USGS NAS site — Sea lamprey, Great Lakes Aquatic Nonindigenous Species Information System — range (status of the Finger Lakes and Lake Champlain populations)
- UniversityAnimal Diversity Web (University of Michigan Museum of Zoology) — Petromyzon marinus (sea lamprey) species account — lifespan (conflicting reading); human-interaction (European consumption)
- GovernmentGreat Lakes Fishery Commission — Sea lamprey overview — diet, human-interaction
- GovernmentGreat Lakes Fishery Commission — Sea lamprey life cycle — diet, lifespan, activity, reproduction, movement
- GovernmentGreat Lakes Fishery Commission — Sea lamprey: what is at risk — diet, human-interaction
- GovernmentFisheries and Oceans Canada — Sea lamprey aquatic invasive species profile — identification, range, body-size, weight, movement, human-interaction
- GovernmentGovernment of Ontario (Ministry of Natural Resources) — Sea lamprey invasive species fact sheet — range, body-size, lifespan, human-interaction
- GovernmentU.S. Fish and Wildlife Service — Sea lamprey species profile — identification, range, diet, body-size, lifespan, reproduction, movement, human-interaction
- GovernmentJoint Nature Conservation Committee (UK) — Sea lamprey, Special Areas of Conservation species account — habitat, human-interaction
- GovernmentInland Fisheries Ireland — Sea lamprey species page (Ireland) — body-size, lifespan, movement
- ReferenceMarine Life Information Network (MarLIN), Marine Biological Association of the UK — Sea lamprey, Marine Life Information Network — identification
- ReferenceOntario Freshwater Fishes Life History Database — Sea lamprey, Ontario Freshwater Fishes Life History Database — range, body-size, weight, lifespan
- ReferencePLOS ONE (Miehls, Holbrook & Marsden 2019; USGS Great Lakes Science Center and University of Vermont) — Miehls et al. 2019, downstream migration of juvenile sea lamprey — activity, human-interaction
- ReferenceIUCN Red List — Petromyzon marinus assessment — The global Red List category and the year of the assessment