Butis Butis

Datasheet

General Description

B. butis is a nocturnal ambush predator with cryptic patterning to blend into surroundings, capable of adjusting body coloration. It aligns itself with surfaces, including swimming upside-down. Belonging to Eleotridae family within Perciformes order, it is commonly known as the Crazy Fish.

Aquarium Setup

Maintained best in brackish water, B. butis requires structures like driftwood, rocks, and low lighting. A gravel substrate can be used, but sand is preferable to prevent ingestion. Plastic plants are recommended, as most aquatic plants aren't suitable. Dried leaf litter can also be added. A tank size of at least 90 liters is needed.

Behaviour

Crazy Fish are territorial and aggressive towards similar species, preying on smaller fish and invertebrates. They are unsociable with conspecifics and should usually be solitary. Suitable tankmates are non-territorial brackish species like Monodactylus and Toxotes.

Feeding and Diet

As ambush predators, they feed on smaller fish, worms, and crustaceans. In captivity, they accept various prepared foods like prawn, mussels, or chironomid larvae. Avoid feeding mammalian/avian meat and live feeder fish to prevent health issues.

Reproduction & Dimorphism

Reproduction rarely occurs in aquarium settings. Sexual dimorphism is unknown. Butis spp. have distinct features, including ctenoid body scales, fewer than 30 rows of predorsal scales, and a protruding chin.

Habitat and Distribution

Found in coastal brackish environments like estuaries, lagoons, and mangroves, B. butis inhabits Indo-Pacific regions widely. Its distribution includes areas from Madagascar to Fiji, with the type locality being the Ganges River in India.

Water Conditions

B. butis prefers water conditions with a hardness of 179-357ppm, pH of 7.0-8.5, and a temperature range of 22-27°C. They thrive in brackish water, adapting to varying salinity levels but may not do well in either full marine or freshwater conditions.