Resource Center Menu

Freshwater Shark

includes rainbow, redtail, bala, apollo, silvertip and black shark species

The generic term "Shark" is applied to many unrelated fish with a similar body shape found all over the world. Freshwater Sharks are not true sharks, but are typically catfish or relatives of carp. Freshwater Sharks add personality and character to an aquarium.

Freshwater Shark

Freshwater Shark Facts

average adult size: 5 to 13+ inches long, depending on species
average life span: depends on species
diet: omnivore
minimum aquarium size: 20+ gallons, depending on species
water temperature: 72-82°F


A well-balanced Freshwater Shark diet consists of:

  • Flake, pellets or freeze dried foods.
  • Live or frozen brine shrimp.


Things to remember when feeding your Freshwater Shark:

  • Feed small amounts two to three times daily, no more than fish will eat in 3-5 minutes.
  • Thaw frozen food before feeding.


  • Keep in an appropriate size aquarium; provide plenty of space for swimming and hiding places.
  • Stable water quality, water temperature, and pH levels are critical to the health of the aquatic life. If you are unsure of your water quality or pH levels, Petco provides free water testing.


  • Some species, such as rainbows and red-tails, are territorial and should be kept individually in a community tank.
  • Some species, such as balas, should be kept in schools of at least three Sharks of the same species.

Habitat Maintenance

Daily: check filter, water temperature and other equipment.

Weekly: check water quality at least once a week.

Monthly: change 10-25% of the total volume of water every 2-4 weeks, or as needed.

Introduce new inhabitants to the aquarium gradually.


Generally, Sharks are compatible with like sized fish of a similar temperament (community with community, semi-aggressive with semi-aggressive).


Signs of a Healthy Shark

  • Clear eyes
  • Eats vigorously
  • Active swimming
  • Good color

Avoid overcrowded conditions; they are a major cause of stress and disease. Maintain good water quality with regular water changes and adequate filtration.

Red Flags

  • loss of appetite
  • spots or fungus on
  • body or mouth
  • listlessness
  • frayed fins
  • clouded eyes

Common Health Issues

Health Issue Symptoms or Causes Suggested Action
Health IssueFin rot Symptoms or CausesFrayed or disintegrating fins; the base of the fins usually reddens. Suggested ActionImprove water quality; consult your aquatic veterinarian for treatment.
Health IssueIch Symptoms or CausesWhite spots appear on fins and body; fish rubs against hard objects or swims awkwardly. Suggested ActionQuarantine fish immediately; use commercial ich remedy for at least two weeks.


Ask an associate about Petco's selection of books on Freshwater Sharks and the variety of Petco Brand products available for the care and happiness of your new pet. All Petco Brand products carry a 100% money-back guarantee.

Because all aquatic life are potential carriers of infectious diseases, such as Salmonella, always wash your hands before and after handling your aquatic life and/or habitat contents to help prevent the potential spread of diseases.

Pregnant women, children under the age of 5 and people with weakened immune systems should contact their physician before purchasing and/or caring for aquatic life and should consider not having aquatic life as a pet.

Go to the Centers for Disease Control at for more information about aquatic life and disease.

This care sheet can cover the needs of other species.

Note:The information on this Care Sheet is not a substitute for veterinary care. If you need additional information, please refer to the sources on the following page or contact your veterinarian as appropriate.

Developed with and approved by a qualified veterinarian.