Aquarium Fish Identification

Aquarium fish are valued pets. They are often expensive and require a great deal of time and effort. Knowing about the types of fish in your aquarium is crucial to determining the kinds of food, habitat and co-inhabitants you'll need to maintain a functional aquarium.

  1. Types

    • There are two types of aquarium fish: saltwater and freshwater. For a home aquarium, the biggest difference between these two types of fish is price. Saltwater fish, such as anglers and butterfly fish, are often captured in the ocean and sold to pet stores. They are sold for prices as high as several hundred dollars. Freshwater fish, like the colorful betta, are usually bred in tanks or ponds and cost much less.

    Physical Characteristics

    • Body shape, color and size are helpful ways to identify aquarium fish. The rainbow shark is easily recognizable, with a gray body, bright red or orange fins and a black spot at the end of its body. Some species of fish vary greatly in color, though body type often gives them away. The corydoras, or cory, catfish is a miniature catfish that can be striped, spotted, gray, green or bronze. Their short bodies and set of front whiskers are unique to the species.

    Features

    • Aquariums can house a variety of creatures, including invertebrates, coral and aquatic plants. Starfish and sea urchins are popular additions to home aquariums. These invertebrates come in a wide variety of colors and often bury themselves in the sand or attach themselves to the glass. The Sally Lightfoot crab is a popular aquarium choice thanks to its spider-like legs and routine cleaning of the tank bottom.

    Diet

    • Many aquarium fish must follow certain diets. Some fish, like the bi-color parrot fish, are carnivorous and eat shrimp, plankton and smaller fish. Most angelfish, on the other hand, eat primarily aquatic plants and corals. It is important to keep plenty of vegetable matter in their diet. Eels have a fondness for invertebrates, such as shrimp, krill and starfish. It is not a good idea to mix species that might eat each other. As a general rule, any fish large enough to swallow another fish most likely will do so. Keep carnivorous fish in tanks with fish their own size, and away from invertebrates like shrimp and starfish.

    Behavior

    • Occasionally, aquariums house fish that operate at different times of day. Nocturnal fish, such as catfish and knife fish, are most active after the sun has set or when the aquarium light has been turned off. These fish particularly love lunar tank lighting. Others are most active during the day and retreat to hiding places during the nighttime hours.