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Freshwater Shark Care Sheet

Developed with and approved by a qualified veterinarian.

This care sheet covers a variety of freshwater shark species, including: 


Freshwater sharks are shark imposters; the generic term "shark" is applied to many unrelated fish with a shark-like appearance found all over the world. Freshwater sharks are not true sharks but are typically catfish or relatives of carp. Freshwater sharks have a variety of temperaments, ranging from peaceful to semi-aggressive, depending on species. These active mid- to bottom-swimmers can add personality and character to an aquarium.

Typical freshwater shark appearance and behavior  

  • Some species, such as rainbows and red-tails, are territorial and should be kept as the only shark in a community tank 
  • Some species, such as balas, should be kept in schools of at least three sharks of the same species 
  • Freshwater sharks have a torpedo-shaped body with pointed dorsal fin and forked tail 
  • Many shark species are territorial 
  • Most sharks have down-turned mouths designed for bottom feeding 
  • Many sharks are scaleless 
  • Most species have sensory organs on the sides of their mouths called barbels  
  • Some species, like the Columbian shark, have a venom gland attached to their dorsal fin, which can inflict a painful sting



Care difficulty Ranges from beginner to advanced, depending on species
Average life span 5–15 years when properly cared for, depending on species
Average adult size 5–13+ inches long, depending on species
Diet: Omnivore
Minimum habitat size 20+ gallons, depending on species
Water temperature: 72-82°F



Habitat size

Keep in an appropriately sized aquarium based on the adult size of the species selected, which can range from a 20-gallon aquarium for smaller species to 300+ gallons for a species like an adult high fin banded shark.

Building your habitat 

  • Water health   
    • Provide proper filtration to ensure optimal water quality to help maintain health. Moderate water circulation should be provided to mimic water currents and high oxygen levels found in the sharks' natural habitat. Stable water quality (pH, ammonia, nitrate, nitrite) and water temperature are critical to the health of aquatic life. If you are unsure of your water quality, bring a sample to Petco for free testing.  
    • An aquatic heater should be used to stabilize water temperature, ensuring it does not fluctuate more than 2 degrees in either direction in a 24-hour period.  
    • Many freshwater sharks will benefit from the addition of freshwater salt to the aquarium; the specific gravity should be kept at 1.004. Always research your species-specific needs before adding freshwater aquarium salt. Do not allow specific gravity to fluctuate more than 0.001 in either direction in a 24-hour period 
  • Décor - Many freshwater sharks become territorial as they mature and should be provided rock caves, hollow logs or other safe hiding spaces 
  • Substrate - Many freshwater sharks have barbels or whiskers, and a less abrasive substrate is recommended to prevent damaging these sensitive appendages 

What does a freshwater shark eat?

A well-balanced freshwater shark diet consists of:

Things to remember when feeding your freshwater shark:

  • Feed small amounts two to three times daily, no more than your fish will eat in 1–2 minutes
  • Thaw frozen foods before feeding

Freshwater shark care 

  • Water care: Maintaining great water quality with regular water changes and adequate filtration is important to help keep your sharks healthy 
    • Daily: Check filter, water temperature and other equipment 
    • Weekly: Test water quality at least once a week 
    • Weekly to monthly: Change 10–25% of the total volume of water every 2–4 weeks, or as needed; change filter media monthly 
  • Avoid overcrowded conditions, which are a major cause of stress and disease 
  • Some species, like the Columbian shark, need brackish water and will require a specific gravity between 1.005 and 1.012 to remain healthy

Where to buy 

Various freshwater sharks are available for purchase at Petco online and in-store; availability varies by location. If visiting your local location, please call ahead to check availability. 

Freshwater shark supplies 

Tank mates 

Generally, sharks are compatible with like-sized fish of a similar temperament (community with community, semi-aggressive with semi-aggressive). Introduce new inhabitants to the aquarium gradually. Due to some of their territorial temperament, it is best to add most sharks as the last fish in the tank. Some species get large enough to eat aquatic life smaller than their mouth; verify adult size when selecting compatible fish. 


Signs of a healthy animal

  • Clear eyes
  • Eats vigorously 
  • Active swimming
  • Good color
  • Free of parasites or disease 


Red flags (If you notice any of these signs, contact your local aquatic specialist or veterinarian.)

  • Loss of appetite
  • Loss of color 
  • Spots or fungus on body or mouth 
  • Listlessness
  • Frayed or discolored fins
  • Clouded eyes or pop-eye
  • Elevated scales
  • Labored breathing
  • Erratic swimming
  • Weight loss
  • Bloating


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 local aquatic specialist or aquatic veterinarian for treatment
Health IssueIch Symptoms or CausesWhite spots appear on fins and body, fish rubs against hard objects or swims erratically, rapid respiration Suggested ActionQuarantine fish immediately; add freshwater aquarium salt and use a commercial ich remedy as directed (some sharks are scaleless, so be sure you select a medication safe for the species you are treating); consult your local aquatic specialist or aquatic veterinarian for treatment
Health IssueBacterial infections Symptoms or CausesCloudy eyes, open sores and/or reddening of the skin Suggested ActionImprove water quality; add aquarium salt; use a commercial antibacterial remedy as directed; consult your local aquatic specialist or aquatic veterinarian for treatment
Health IssueCottonmouth or columnaris Symptoms or CausesCottony white growths along the body and/or gills, frayed fins and gills turn brown and necrotic in late stages; caused by bacterial infection Suggested ActionQuarantine fish; improve water quality; lower aquarium temperature to 72°F to deter bacteria from growing; medicate as directed; consult your local aquatic specialist or aquatic veterinarian for treatment



  • Can sharks live in freshwater? Freshwater sharks are not the same as marine sharks. These shark-like fish are members of either catfish or carp families.  
  • What kind of sharks can live in freshwater? There are several species of freshwater shark-like fish such as Redtail, Rainbow, Apollo, Bala and Iridescent.  
  • How big do rainbow sharks get? Rainbow sharks can reach an adult size of 6” 
  • What do rainbow sharks eat? Rainbow sharks are omnivores and can be offered flake, pellets or freeze-dried foods and live or frozen brine shrimp as well as other frozen diets.  
  • How big do bala sharks get? Bala sharks can reach an adult size of 10” to 13”  
  • How big do redtail sharks get? Redtail sharks can reach an adult size of 6” 
  • How big do silvertip sharks get? Colombian, aka Silvertip shark can reach an adult size of 10” 


Additional care sheets


Notes and resources

Ask a Pet Care Center associate about Petco's selection of products available for the care and happiness of your new pet. All products carry a 100% money-back guarantee.

Because all aquatic life are potential carriers of infectious diseases, such as atypical Mycobacterium and 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, senior citizens 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.

The information on this care sheet is not a substitute for veterinary care. If you need additional information, please contact your veterinarian as appropriate.