All fish / Eleotridae

Fat Sleeper

Dormitator maculatus

Also known as fat sleeper goby, spotted sleeper, sleeper goby, guavina, fat sleeper gudgeon, dormitator, 斑点塘鳢

A stocky, thick-bodied sleeper with a broad head, brown mottled flanks and a bright blue spot behind the gill cover, with males showing blue and red edging on the fins. It is kept by brackish fish enthusiasts for its hardy nature and its habit of resting motionless on the substrate before darting after food.

Care at a glance

Care level

Moderate

Temperament

Semi

Adult size

25 cm

Temperature

22 to 28 °C

pH

7 to 8.5

Smallest tank

300 litres

Keep as

Singly or as a group in a large tank

Diet

Omnivore: sinking pellets, frozen bloodworm, shrimp, earthworms and vegetable matter including algae wafers

Swims

Bottom of the tank

Lifespan

5 to 10 years

Water

Brackish

Wild range

Western Atlantic coasts from North Carolina through the Gulf of Mexico and Caribbean to Brazil

Breeding

Spawning happens in estuaries, where females scatter large numbers of tiny eggs that hatch into minute planktonic larvae. Breeding in home aquariums is very rarely achieved because the larvae need marine or brackish conditions and very small live foods.

Good to know

Often sold small as a freshwater fish, but it grows to 25 cm or more and does best in brackish water. It will eat any fish or shrimp small enough to swallow.