Dartfish are a peaceful species of fish and do best when kept in groups of 4 or more. They also make excellent additions to most community aquariums. However, they should not be housed with larger, more aggressive tank mates that could harass or prey on them. If kept with larger, more aggressive tank mates, dartfish can sometimes stay hidden for long periods of time and eventually end up starving to death.
They are known jumpers and should be housed in aquariums equipped with tight fitting lids. They are also easily startled and can attempt to jump out of an aquarium in flashes of panic.