Bony fish · Gasterosteiformes · Gasterosteidae

Three-spined Stickleback

Gasterosteus aculeatus

Least Concern

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

The male builds a nest of water plants bound together with 'spiggin', a sticky protein he secretes through his kidneys, and defends the nest and the young fiercely.

Weight

1 kg – 4 kg

Size

3 cm – 11 cm

Lifespan

2 years

Diet

Carnivore

Feeds mainly on other animals.

Activity

Diurnal

Active mainly during the day.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Easy

OceanFreshwaterCarnivore Diurnal Solitary Fish Ocean Freshwater

55countries 141parks 19dive sites

Fun facts

It is a key model organism in evolutionary genetics.
It eats small crustaceans, aquatic insect larvae and occasionally its own eggs and fry.
It lives in coastal waters, estuaries, rivers and lakes of temperate circumpolar regions.

Life cycle & biology

Skeleton type: Vertebrate - internal bony skeleton (fish)
Habitat & environment: Coastal waters, estuaries, rivers and lakes of temperate circumpolar Europe, Asia and North America
Birth weight: Tiny larva at hatching
Size at birth: Tiny larva at hatching
Sexual maturity: 1-2 years
Gestation / incubation: 7-8 days at 18-20°C
Litter / clutch size: Up to 400 eggs per female, laid in a nest built by the male

Sources consulted: ADFG Alaska; PLOS One; FishBase; Animal Diversity Web; Wildlife Trusts; University of Puget Sound; Animalia.bio; Better Planet Education