Both the freshwater and saltwater hobby include fish called sharks. In freshwater, fish sold as "sharks" are usually more closely related to goldfish than real sharks. In the saltwater side of the hobby, true sharks are available for pets, but most true sharks are poorly suited to home aquariums. A few species of saltwater sharks can thrive under the careful care of experienced hobbyists.
Pet shops sell several freshwater species with "shark" in their common names. While several species of freshwater sharks exist, none of the fish that show up in the freshwater aquarium hobby are really sharks. Instead, carp and catfish with triangular dorsal fins are labeled shark fish. Still, these fish who superficially look like sharks can make a nice conversation pieces. Research the specific aquarium shark you want to keep, since they can range from a few inches to a tank-busting several feet as adults.
Saltwater sharks are among the most expensive and challenging aquarium fish. The first big expenses is that sharks need huge aquariums, several times their lengths. At minimum, the smallest true shark needs an aquarium of at least 100 gallons. Sharks require aquariums with rounded corners to prevent damage to their noses. Sharks also require pristine water with no heavy metal contamination. Shark tanks should contain a minimum of decorations to keep their inhabitants from injuring themselves.
Feeding sharks requires special attention. Many sharks refuse food, especially when first introduced to captivity or after shipping. In order to get sharks to eat, you'll have to spear some seafood on ridged aquarium tubing and wiggle the food near the shark to get his attention. Don't move toward the shark with the food; let him come to you. Most species only need one or two feedings per week in aquariums.
Of the hundreds of shark species, only a handful are suitable for captivity. Of these, only a handful can thrive in the absolute best home aquariums. Unless you want to spend hundreds of dollars on a chiller unit, you should stick to tropical species. The epaulette shark, bamboo shark and banded cat sharks all stay small, come from the tropics and adapt to captivity better than most sharks. Even these "easier" species still require the pinnacle of aquarium care to survive in the home aquarium.
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