Rainbow Shark Fact Sheet

The rainbow shark, a popular freshwater aquarium fish, has always been among my favorites. When I first began keeping fish, I was amazed by the amount of sentience and personality that these hardy cyprinids display. While rainbow sharks are fairly forgiving, I learned the hard way that they must be kept within good water parameters. Furthermore, rainbow sharks require an adequate amount of space and a healthy diet.

Know these facts about rainbow sharks before purchasing one of these red-tailed beauties.

Adult Size

Most rainbow sharks in pet stores are still very young. A rainbow shark may exceed six inches.

Tank Size

Rainbow sharks become boisterous when they are kept in tanks that are too small. A large tank of 55 gallons or above is necessary to maintain proper health and stimulation.

Social Behavior

The rainbow shark is not a social fish; do NOT keep more than one in a tank. They are very aggressive toward one another and to similar "shark" species, such as the red-tailed shark.

Tank Mates

Keep rainbow sharks with fish of similar size. They may bully small fish, such as danios or tetras, unless there is adequate swimming space. Very large fish may try to eat rainbow sharks, and bottom-dwellers like the pleco may compete excessively for territory.

Life Span

Well-kept rainbow sharks have an average life expectancy of 5-7 years, though many die prematurely from poor water conditions.

Diet

Don't let the name fool you-- this "shark" is a vegetarian. Rainbow sharks need algae, pellet food and herbivore flake food.

Breeding

Rainbow sharks are very difficult to breed in home aquariums because they fight excessively; one fish is likely to die before the pair gets around to laying eggs. Most rainbow sharks are bred on commercial fish farms.

Water Parameters

The rainbow shark prefers a pH of about 7, though a pH as high as 8 or as low as 6 can be tolerable for brief periods of time. These fish are relatively sensitive to nitrates and ammonia; keep both levels as low as possible.

Temperature

A heater is a must-have for these tropical fish. Keep rainbow sharks at a temperature between 75-80 degrees at all times.

Variations

Albino rainbow sharks are a popular alternative to the traditionally pigmented wild specimens. These fish are white with red fins and eyes.