Spectrum Brands Pet has added GloFish Sharks to its line of GloFish fluorescent fish. GloFish Sharks are a sleek and elegant addition to any freshwater aquarium—whether fish keepers are adding to a tank with other fish or completely transforming their aquarium to a GloFish tank. GloFish Sharks are members of the minnow family, not actual sharks. Because these fish can reach up to 4 in. in length, they should only be placed in aquariums 20 gal. or larger. They exist peacefully with other GloFish and nonfluorescent community fish. They come in sunburst orange and galactic purple. They get their natural color from their parents and are not injected, painted or dyed.