Fish in the wild don't forage for multicolored flakes of nutritionally balanced, store-bought food. Instead they nibble on plants, swallow an insect now and then, or eat whatever other nutritious morsels they find floating around in their lake, stream or reef.

Lucky for us, pet fish aren't too picky. Although some choosy eaters aren't easily pleased, most willingly partake of prepared foods. To ensure your finny friends eat a well-balanced diet, weigh these considerations before picking a menu:

Food Types

Prepared foods, also known as canned foods, are designed to provide a complete and balanced diet for your fish. Canned foods come in a variety of forms.

Floating flakes are the most common prepared food and are available in a wide variety, depending on the type of fish and the needs of the fish. For example, some flakes are designed to counter nutritional imbalances and some can enhance color or growth. Sinking pellets or granules are appropriate for fish who like to feed at the bottom of the tank, while floating pellets are for those fish who like to feed at surface. Additionallly, floating pellets make it easier for you to monitor how much your fish are eating.

Although preservatives help prevent spoilage, the food's vitamins and nutrients deteriorate over time. Purchase only enough food to last one month, or freeze excess food to help preserve nutrients. But be careful-foods spoil quickly or grow mold in moist environments, so always use airtight containers. Most foods meet the needs of multiple species, but some fish may crave and need additional nutrients. Spice up your pet's diet with crustaceans, worms, plants, and other healthy treats. Your pet will appreciate the variation. Carnivorous fish like cichlids, oscars, or piranhas may turn up their noses at prepared food, but with time and patience, they can be trained to eat many of the fresh, pelleted and frozen diets specially prepared for carnivorous fish.

Like their carnivorous counterparts, some smaller tank species also consume cultured brine shrimp, tubifex worms and microworms. Many saltwater fish don't order off the standard menu. For blue tang, algae is the dish du jour. Only coral polyps will satisfy the butterfly fish's particular taste buds. Certain wrasses feed off minute crustaceans that live on larger fish.

Feeding Stimuli

What causes fish to seize and swallow food? The stimulus varies among species, and the cue may be visual or chemical.

Environmental factors such as temperature, water quality, and the type and duration of lighting affect appetite. Of course, health is also a significant factor. Sick fish will forage less despite exposure to feeding stimuli.

Dietary Habits and Preferences

Feeding your finned companions involves more than just sprinkling a few flakes in the tank. You need to learn their feeding habits and preferences. While some fish like to nibble food floating at or near the water's surface, others prefer cruising the aquarium's midrange for dinner. Bottom-feeding catfish are not likely to venture to the surface for a floating pellet, just as other species would never dream of rooting in gravel after a sinking morsel.

If you're unsure of what your picky pet prefers, consult an Aquatic Specialist at your local Petco or a reference guide.