Lampreys · Petromyzontiformes · Petromyzontidae

Sea Lamprey

Petromyzon marinus

Least Concern

The species is abundant and widely distributed; it faces no significant short-term risk. See full glossary

Accidentally introduced to the North American Great Lakes in the early 20th century, it has driven at least 3 native fish species to extinction there by parasitising them to death.

Weight

300 g – 1.4 kg

Size

35 cm – 90 cm

Lifespan

8 years

Diet

Carnivore

Feeds mainly on other animals.

Activity

Nocturnal

Active mainly at night.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Easy

OceanFreshwaterCarnivore Nocturnal Solitary Ocean Freshwater

18countries 45parks 21dive sites1same family

Fun facts

It drove at least 3 native fish species in the Great Lakes to extinction after it was introduced.
It fastens onto other fish with its sucker mouth to feed on blood and body fluids.
It is semelparous: it dies shortly after spawning, which it does only once in its life.

Life cycle & biology

Skeleton type: Vertebrate - jawless cartilaginous skeleton (agnathan)
Habitat & environment: Atlantic coasts and rivers of North America and Europe; introduced and highly invasive in the North American Great Lakes
Birth weight: A tiny egg; a blind ammocoete larva 11 mm long on hatching
Size at birth: A blind ammocoete larva some 11 mm long, which stays buried in sediment for 3 years or more
Sexual maturity: 18 months to 5 years after metamorphosis, depending on how available hosts are
Gestation / incubation: 10-13 days of egg development before hatching
Litter / clutch size: Tens of thousands of eggs per female in a single spawning

Sources consulted: PubMed (life cycle marine stage study); Sea Lamprey NJ DEP fact sheet; AnAge (genomics.senescence.info); Pond Informer; Illinois DNR; Animal Diversity Web; U.S. Fish & Wildlife Service; PubMed (oxidative stress ageing study)