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Pet Owner Version

Introduction to Fish


Ruth Francis-Floyd

, DVM, DACZM, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida;

Barbara D. Petty

, DVM, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida

Reviewed/Revised Feb 2020 | Modified Oct 2022

Aquariums bring the beauty and wonder of the underwater world into your home. Although the average fish owner may not typically think of veterinary care for fish, aquatic medicine is becoming more mainstream, especially with the growth in popularity of the Japanese koi and Chinese fancy goldfish show industries. These show-quality fish can cost thousands of dollars, and veterinary care is common. Although a relatively small number of veterinarians throughout the United States work with fish, the numbers are increasing. To find a veterinarian who works with fish, contact the American Veterinary Medical Association or your local veterinarian for a recommendation.

Veterinary care for pet fish, exhibit animals, and valuable breeding stock includes radiology, ultrasonography, laboratory procedures including blood tests, and drug therapy. Advances in surgery have also improved diagnosis and treatment of diseases in fish.

The world of home aquariums is vast and varied. Aquariums and their inhabitants can be selected to be feisty or serene, showy or subdued, social or solitary. They can also be low maintenance or require lighting schedules, intricate filtration systems, and precise environmental and nutritional management.

The 2 basic types of aquariums are freshwater and saltwater. A water environment in which saltwater and fresh water mix is known as brackish. In nature, this occurs in estuaries, marshes, and mangrove swamps.

Many different species of fish can be kept together in saltwater or freshwater worlds. For example, certain African river species can be kept with some Australian species; some types of Pacific reef fish can be kept with certain fish from Caribbean coastal flats. However, different species may have requirements that differ greatly, and therefore they cannot be kept together. For example, water temperature and pH requirements can differ between species. Also, more aggressive species might attack or eat other fish in the tank. Therefore, you should learn as much as possible about the types of fish you are considering for your aquarium before purchase.

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