Three-spined Stickleback

Gasterosteus aculeatus

  1. Wildlife
  2. Freshwater fish
  3. Three-spined Stickleback


The three-spined stickleback is a small fish found in ponds, lakes, ditches and rivers. The stickleback is an aggressive predator, feeding on invertebrates and other small animals including tadpoles and smaller fish. In the spring the male develops a bright red throat and belly and performs a courtship dance to attract a mate. He builds a sheltered nest out of vegetation, under which the female will lay up to 400 eggs. The male then defends the nest from other fish until the young hatch up to four weeks later.

How to identify

Brownish above with silvery sides and belly, the three-spined stickleback is the fish that is most likely to be caught when pond-dipping. Identified by the three sharp spines on the back.

Where to find it

Found throughout the country.


When to find it

  • January
  • February
  • March
  • April
  • May
  • June
  • July
  • August
  • September
  • October
  • November
  • December

How can people help

To help to look after sticklebacks and other fish species, The Wildlife Trusts work with landowners, statutory bodies, water companies and other organisations to help manage river and wetland habitats sympathetically. You can help by supporting your local Trust and becoming a member; you'll find out about exciting wildlife happenings, events on your doorstep and volunteering opportunities, and be helping local wildlife along the way.

Species information

Common name
Three-spined Stickleback
Latin name
Gasterosteus aculeatus
Freshwater fish
Length: 4-7cm Weight: 1g Average Lifespan: 3 years
Conservation status