Matt Clarke with some need to know facts on an unusual fish.
Common name: Crazy fish
Scientific name: Butis butis
Origin: Found across the Indo-Pacific from Fiji to the coast of East Africa.
Habitat: Usually found in weedy rivers, swamps and mangroves. Found in marine, brackish and freshwater environments.
Water: These were being kept in a centralised system containing freshwater with salt added to a rate of around 3g/l. They should adapt to freshwater if done slowly.
Diet: A micropredator which eats shrimps, prawns and fish. The one shown here accepts flakes.
Size: Up to about 15cm/6".
Aquarium: Needs a tank of about 90cm/36" or more, containing some shelter from plants or bogwood. Do not keep Butis with fish small enough to eat.
Notes: The eleotrid, also known as the Bony-snouted gudgeon or Duckbill sleeper, is a master of disguise and colouring will depend on the substrate and its surroundings. It often hangs motionless in mid-water, often upside down, giving it the appearance that it has died. It's capable of an amazing turn of speed. There are five Butis species: B. amboinensis, B. gymnopomus, B. humeralis, B. koilomatodon and B. melanostigma.
Availability: On sale at Maidenhead Aquatics in Harlestone Heath. Shops who import their own fish should be able to order it.
Rarity rating: Rarely seen.
Price: 6.50 for a 5-8cm/