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
Owner questions the things everyone asks
How often should I feed my Three-spined Stickleback?
Feed your stickleback daily, as they are active little predators. Offer small live or frozen meaty foods like worms, insect larvae, and tiny crustaceans. For exact amounts, check the food label and ask your vet if unsure.231 Furry Diary plan
What does a Three-spined Stickleback eat, and what should it never eat?
They thrive on meaty foods such as worms, small crustaceans, insect larvae, and even tiny fish. Avoid anything not suited for a carnivorous fish, like plant-based flakes. For a complete list of safe foods, consult a good breeder or exotic-pet vet.231
How much space does a Three-spined Stickleback need?
These fish enjoy a spacious, shallow tank with plenty of plants and hiding spots. The exact size depends on how many you keep, so ask a good breeder or an exotic-pet vet for guidance.31
What temperature, light or water does a Three-spined Stickleback need?
As a coldwater fish, keep the water between 4 and 20°C. Provide a well-planted tank with gentle filtration and moderate lighting. They prefer shallow, plant-rich water over mud or sand.21
How often should I clean a Three-spined Stickleback's home?
Furry Diary's starting plan suggests a weekly 25, 30% water change, weekly glass cleaning, and a monthly filter rinse. Adjust the schedule based on your tank's size and how many fish you have. Furry Diary plan
Can a Three-spined Stickleback live with others?
Yes, they form schools outside the breeding season, but males become territorial in spring when nesting. Provide plenty of plants and hiding spots, and avoid very small tank mates that might be eaten.231
How long does a Three-spined Stickleback live?
With good care, they can live between 2 and 8 years. A stable, clean environment and proper diet help them reach their full lifespan.231
Can I handle a Three-spined Stickleback?
It's best not to handle them, they have sharp spines that can hurt you and stress the fish. Use a soft net only when necessary, and always move them gently.23
Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Furry Diary's own starting care plan. A friendly guide, not a vet's advice.
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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 support@furrydiary.app 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
- VCA Animal Hospitals: Feeding times and frequency for your dog vcahospitals.comused for owner questions
- ASPCA: Dog grooming tips aspca.orgused for owner questions
- ASPCA: Cat grooming tips aspca.orgused for owner questions
- ASPCA: People foods to avoid feeding your pets aspca.orgused for owner questions
- RSPCA: What to feed your rabbit rspca.org.ukused for owner questions
Checked 2026-09-30. Text is written in our own words from these sources.