Three-spined stickleback
Scientific name: Gasterosteus aculaeatus
A diminutive but aggressive predator, the three-spined stickleback hunts tadpoles and small fish. It is also known for fiercely protecting its nest of eggs until they hatch. Look for it in ponds, lakes and rivers.
Top facts
Stats
Length: 4-7cmWeight: 1g
Average Lifespan: 3-5 years
Conservation status
Common.