What do Fish Eat?

By PetMD Editorial on Feb. 11, 2016

By Kali Wyrosdic

There are thousands of different types of fish in all different colors and shapes, so it makes sense that there is no one universal fish food to satisfy them all. Fish can be found living in all different parts of the world, in all different kinds of ecosystems, and their living, eating and breeding habits evolve as a direct result of the environments that they live in.

Catfish are perhaps one of the best illustrations of how differently some fish eat. Catfish are omnivorous scavengers, and live in sluggish-to-stagnant muddy waters, eating whatever they get their fins on. Other fish, like blennies, gobies and damselfish, are marine reef fish, which means that they make coral reefs their homes and feed on a variety of algae, plankton and small invertebrates. One type of fish, the gar, has a diet that consists entirely of other fish, making it a piscivore.

We’ve established that different fish like to eat different things, but what does that mean when it comes to feeding pet fish? Below you’ll find an overview of the different types of common fish foods that are commercially available at pet stores.

Flake Fish Food

Flake fish food is available for all types of fish. Marine flake food is manufactured for saltwater fish diets, while tropical flake food is for freshwater fish that like to live in groups (called community fish). Bettas, cichlids and goldfish have their own specially formulated flake foods and shouldn’t be fed generic foods.

Flakes are the easiest kind of fish foods to use; simply sprinkle a few on top of the water and watch your fish come to feed. Be careful not to overfeed your fish!

Pelleted Fish Food

Pelleted fish foods can be bought in floating or sinking varieties and are also manufactured to meet the nutritional requirements of specific types of fish. Pellets are better for larger breeds of fish like oscars, groupers and cichlids. Never feed your fish pellets that are too big, as this can cause serious digestion issues.

Freeze Dried, Frozen and Live Foods

Freeze-dried and frozen foods including bloodworms, brine shrimp, krill and plankton all make great treats to supplement your fish’s normal diet with. They are available at pet stores nationwide and can be kept in your freezer. Fish love these tasty treats, but it’s best to use only the freeze-dried or frozen varieties, as live food (like worms) can transmit diseases to your pet.

Other Treats for Fish

For fish that are herbivores and omnivores, spirulina is extremely nutritious and should be given as part of the fish’s complete diet. Dried sheets of seaweed can also be purchased and fed to your fish as treats, but should be given sparingly.

Image:  / Shutterstock

Help us make PetMD better

Was this article helpful?

Get Instant Vet Help Via Chat or Video. Connect with a Vet. Chewy Health