Not furry, but we like them anyway.
Three-spined Stickleback
Gasterosteus aculeatus
Also called Threespine stickleback, Tiddler, Tittlebat
From Northern Hemisphere coastal and fresh waters north of about 30 N, from Greenland to Japan and south to the Black Sea, Iberia and North Africa12
At a glance the quick version
Looks how to spot one
Small spined fish with bony side plates
A small, streamlined fish with three sharp spines along its back, from which it takes its name. Sea-going forms wear a row of bony plates along their sides, while many freshwater forms have few or none.23
Personality what they are like
A bold little predator. In spring the males become territorial, dancing to court females and seeing off rival males from their nest area.23
Grooming and care the hands-on bits
A coldwater fish; FishBase lists a temperature range of about 4-20 C. Breeding males need plant material to build their nests.12
Home where they are happiest
Shallow, plant-rich water over mud or sand, in ponds, lakes, ditches, rivers and coastal waters.13
Food basics what goes in the bowl
A meat eater that takes worms, small crustaceans, insect larvae and adult insects, plankton and even tiny fish or tadpoles.123
Company who they like around
Forms schools outside the breeding season; breeding males become territorial around their nests.12
The story where it all began
The species has lived around the northern oceans for millions of years and has repeatedly moved into fresh water, where it has adapted fast to local conditions. That makes it a favourite of evolutionary biologists, and Niko Tinbergen's famous behaviour studies used the male's red throat to show how a simple signal triggers a response.2
Fun facts for the dinner table
- 1
The male glues his nest together with spiggin, a sticky protein made in his kidneys.2
- 2
After spawning, the male fans the eggs with his fins day and night until they hatch about a week later.2
- 3
Niko Tinbergen showed that the red belly of a male acts as a signal that triggers attacks from rival males and attracts females.2
- 4
It is the fish most likely to turn up in a net when pond-dipping in Britain.3
- 5
Some populations lost and then regained their bony armour plates within decades, a well studied case of rapid evolution.2
Recognised by the official bits
- IUCN Red List
- Least Concern (assessed 30 May 2022)1
- FishBase
- Listed as used in public aquariums1
The care rhythm Furry Diary remembers it for you
A typical home-care rhythm for a Three-spined Stickleback. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- Feedingevery day
- Water changeAbout 25 to 30% of the waterevery week
- Water testevery week
- Glass cleanevery week
- Filter rinseevery month
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Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at [email protected] and we will fix it.
- FishBase: Gasterosteus aculeatus fishbase.seused for size, max age, distribution, temperature, diet, reproduction, IUCN status
- Wikipedia: Three-spined stickleback en.wikipedia.orgused for size, body, colours, breeding, history, fun facts, other names
- The Wildlife Trusts: Three-spined stickleback wildlifetrusts.orgused for size, weight, lifespan, habitat, identification, fun fact
Checked 2026-09-30. Text is written in our own words from these sources.