I added a rainbow shark to my 150 gallon tank a few months ago, and I have really fallen in love with the bright flashes or color she adds to the tank.

Watching her munch on every leaf and wood surface around is also rather adorable. I’d never really seem a creature forage the way that the rainbow shark does, making her a favorite member of my 150 to watch. They make great aquarium cleaner fish of sorts – finding uneaten food bits in every nook and cranny of the tank.

Though called a shark by name, Rainbow Sharks are not true sharks. They fall under the category of ray-finned fish instead. These guys can grow up to 9 or so inches, but usually fall short around 7 inches or so in most aquarium environments.

Males are sleaker than females and have black lines along their tailfins, unlike females. Given this, I think that I have a female.

Rainbow shark can be difficult to care for given their possibilities for aggression and need for larger tank sizes. 55 gallons or more is highly recommended for a single Rainbow shark,with typical community pH around 7.0 and a temperature of 72 to 79 degrees Fahrenheit.

Mine loves to swim the entire length of my six foot 150 gallon tank, and she sure is fast! She is one of the more aggressive fish in the tank, occasionally chasing my gold barbs or other fish in a sudden burst of speed. Keeping multiple rainbow shark in the same tank is generally a bad idea unless their environment has been carefully planned and researched.

Breeding rainbow shark hasn’t been well documented or recorded in the aquarium setting, but I’m still tempted to try adding a second rainbow shark in the future if I lower the stocking of my 150. It would be a nice experiment, and I’d love to watch two of these fast, brightly colored fish zip around my tank. If you’ve ever tried having more than one of these in your tank, let me know how it went!