Three-spined stickleback
The Three-spined stickleback (Gasterosteus aculeatus) is a fish that lives in both fresh and salt water of the family Gasterosteidae that grows up to 11 cm.
Widespread in the northern hemisphere in fresh, brackish and coastal water of Europe, North Asia and North America.
Want the complete picture on the Three-spined stickleback?
Description
The three-spined stickleback is a small fish of the family Gasterosteidae usually around 5 cm and at most 11 cm. It is characterised by three free spines in front of the dorsal fin, a row of bony lateral plates instead of scales, and a slender, torpedo-shaped body. Outside the breeding season it is silvery-grey to greenish; breeding males develop a bright red throat and belly and blue eyes. The species lives in fresh, brackish and coastal water across the northern hemisphere and hunts small invertebrates. In spring the male builds a nest, fiercely defends a territory and guards the eggs and young. This behaviour has made the stickleback a classic subject in behavioural biology.
Frequently asked questions
How do you recognise the Three-spined stickleback?
The Three-spined stickleback has a torpedo-shaped body, is mainly silver-grey and shows a plain pattern. Small fish with three separate dorsal spines and bony lateral plates; in the spawning season males colour bright red on the throat and belly and build a nest.
Where does the Three-spined stickleback live?
The Three-spined stickleback lives in both fresh and salt water and is mostly found around mixed bottom. Widespread in the northern hemisphere in fresh, brackish and coastal water of Europe, North Asia and North America.
How big does the Three-spined stickleback get?
The Three-spined stickleback grows to a maximum of about 11 cm. On average the species is around 5 cm.
Is the Three-spined stickleback dangerous to humans?
No, the Three-spined stickleback is harmless to humans. None required: harmless, though the dorsal spines can lightly prick if handled carelessly.
Is the Three-spined stickleback edible?
The Three-spined stickleback is not usually eaten.
More photos
Easily confused with
These species look like the Three-spined stickleback and live in the same waters.
Want the complete picture on the Three-spined stickleback?
Point your camera at the fish and Fin names the species in seconds. Free, and the Three-spined stickleback is one of 12,519 species in the app.
Or scan with your phone
All data
Identification
Appearance
Habitat & distribution
Behaviour & biology
For anglers
Safety
Status & sources
Same genus Gasterosteus
More from the family Gasterosteidae
Want the complete picture on the Three-spined stickleback?
Point your camera at the fish and Fin names the species in seconds. Free, and the Three-spined stickleback is one of 12,519 species in the app.
Or scan with your phone