Brook Stickleback (Culaea inconstans) in a freshwater aquarium
Varies carePeacefulMid dwellerNorth America

Brook Stickleback

Culaea inconstans

The Brook Stickleback (Culaea inconstans) is a peaceful fish that's rewarding to keep. Give it a tank of at least 75 litres (20 US gallons), water held at 50-68°F, and a pH of 6.5-7.5.

Care levelVaries
TemperamentPeaceful
Min tank size19.8 US gal
pH range6.5-7.5
Temperature50-68°F
Max size1.8 in (4.5 cm)
Captive lifespan2-5 years
SchoolingNo
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Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.

Natural distribution

North America

  • Central America & Mexico

Regional colours match the stocking calculator's origin map.

Brook Stickleback Tank Setup

A tank of at least 75 litres (20 US gallons) works well. Keep the water at 50-68°F with a pH around 6.5-7.5, and set up both cover and open swimming space where they spend most of their time (Mid).

What Do Brook Sticklebacks Eat?

They're not fussy eaters - feed a varied diet, rotating good-quality dry, frozen, and gel foods rather than the same thing every day, and match the food size to their mouths.

Brook Stickleback Tank Mates

The Brook Stickleback is peaceful, which is the first thing to weigh up when you choose tank mates. Good matches come down to the whole stocking list working together - temperature, tank size, and temperament - not any single label. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.

Are Brook Sticklebacks Good for Beginners?

Care demand varies by line and setup. Match the care level to how often you actually test and change water.

Brook Stickleback - frequently asked questions

What size tank do Brook Sticklebacks need?

Brook Sticklebacks need a tank of at least 75 litres (20 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.

What water parameters do Brook Sticklebacks need?

Keep them at 50-68°F with a pH of 6.5-7.5, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.

What do Brook Sticklebacks eat?

Brook Sticklebacks are omnivores and aren't fussy eaters. Feed a varied mix of good-quality dry, frozen, and gel foods, and match the food size to their mouths. Feed small amounts once or twice a day, and remove anything they don't eat.

Are Brook Sticklebacks good for beginners?

It depends on the setup. Match Brook Sticklebacks to how often you actually test water and perform maintenance.

Building a community? Run the full list through the stocking calculator before you add anything else.

Fish to avoid mixing with Brook Sticklebacks

These well-known species are commonly sold alongside this fish but are not recommended tank mates - verify before purchasing.

  • AxolotlPredator - Axolotl will eat or injure smaller tank mates
  • Common GoldfishGoldfish - prefer cooler, harder water that tropical fish cannot tolerate