Skip to content Skip to sidebar Skip to footer

What Do Crabs Eat In Fish Tanks?

What Do Crabs Eat In Fish Tanks?

Many aquarists come across the idea of keeping a crab in their fish tank but are put off by the lack of information about the foodstuffs a captive crab consumes in fish tanks. This comprehensive guide will get you up to speed on the dietary requirements of crabs in aquariums so that you can make an informed decision on whether or not a crab is a suitable pet for you!

What Do Crabs Eat In The Wild?

Many crab species are omnivores and typically eat plants and meat. The food sources they usually depend on vary according to their species and environmental factors, such as water temperature and salinity. Some of the more common foods they eat in the wild include algae and vertebrate muscle tissue.
  • Algae
  • Kelp
  • Aquatic plants
  • Animal Carcasses
  • Live Seafood
  • Insects and Insect Larvae
The foods your pets consume in the crab tank must provide them with the vital nutrients they require. By way of example, they should eat a variety of foods.

Feeding Your Crab In The Fish Tank

As a crustacean's appetite can be fierce, be careful not to overfeed your crab.
The most common foods suitable for fish tanks include crustaceans.

Frozen Seafood

Frozen seafood is nutritious and tasty, making it ideal for satisfying your crab's hunger. Additionally, you will not need to be concerned about potential illnesses being transferred from live seafood to frozen seafood.

Its convenience makes it an excellent alternative food for crabs. It can be stored in the freezer and doesn't need to be thawed. Just defrost and feed!

When shopping for frozen crab food for your crabs, be cautious about trying to avoid added preservatives, particularly Ethoxyquin and Sodium Benzoate, in the food listing. These chemicals are added to preserve the food and prevent it from spoiling, but they are especially harmful to your pets and fish.

Live Seafood

Livebearer fry or feeder fish that are not within you can provide sustenance to your crabs. Crabs are drawn to fry, so if you just birthed a litter, try dropping them in the tank with your crabs.

Don't forget that you shouldn't feed your crab creatures living in the tank previously, as these fish are infamous for causing problems for your crab. In addition, refrain from feeding your dead crab fish, as this may expose it to illnesses.

Apart from using fish as food, you can also feed your crab with live seafood, such as snails and shrimp. Be aware that if you provide your crab with live foods, you'll need to be careful when partaking with them, as it is likely that your crab will still want more!

Brine Shrimp

Brine shrimp are good food for crabs if a tank contains crustaceans. They are packed with nutrients and minerals required for crabs, giving them an even healthier meal.

Live brine shrimp or their larvae can usually be bought in your local aquatics store. If you would like to add shrimp to your saltwater aquarium, either drop some into the tank or begin spawning them in it. Within a few days, your aquarium will blossom with lots of shrimp to feed your crabs.

Crabs, on the other hand, need to be fed a little more work than egg-laying shrimp larvae before they are ready to eat. You'll need to raise these crabs to feed your shrimp, so you should get brine shrimp eggs online (for approximately $15) and invest in a brine shrimp hatchery (with the shrimp eggs). You'll need to let the eggs hatch, and after a couple of days of incubation, you should have plenty of living shrimp.

Mysis Shrimp

Mysis shrimp are an excellent alternative to brine shrimp. They are high in protein and go down well with staple foods like TetraFin flakes and Hikari Crab Cuisine.

You can pick up Mysis shrimp at your local aquatic store. You can also place your order online. Mysis shrimp are very easy to prepare; you must peel the shells and feed them to your crabs.

It's essential to keep in mind there are certain times of the year when Mysis shrimp aren't available, so you may wish to shop around.


If you have ever fed livebearer fish fry to your fish, then it's likely that the local aquatic retailer you visited supplied the bloodworms you used in their crab food recipe. Bloodworms are a very healthy food that makes excellent crab food.

You've got several options: You could use just a few of them out of their container, and they will definitely like you for it, or you can likewise try treating them with dried blood worms purchased at most pet stores. They're cheap and come in various sizes, so just be sure to buy the proper size for your crabs!

Parasites can be carried by bloodworms, so if you feed your crabs with them, make sure to give your worms a quick rinse.

Crustacean Pellets

Crabs eat most other crustaceans in the wild, so it makes sense to feed them a similar food source in a fish tank. Crustacean pellets are typically shrimp or krill, making for a great source of crab food since they are high in protein and minerals.

These pellets have a reasonably long shelf life compared to other foods, so you won't have to constantly replace them. Most happen to be packed with all the nutrients crabs are supposed to have, so they won't have to worry about missing anything in their diet.

Consider big versus small-sized pellets when choosing a crab breed. For wet fish food, I favor using Zoo Med s Krill and Shrimp Pellets, although Hikari is likewise a good choice.

Algae Wafers

Crabs typically like algae wafers, another excellent option for supplementing their diet. Rich in fiber, these wafers are a perfect staple food for any crab, and they also supply them with a source of healthy vegetable matter. The fact that many crabs forage for aquatic algae in their natural habitats makes this a great choice as a food.

Crustacean wafers are most often made from Macrocystis Pyrifera seaweed, found in oceans across the globe. The seaweed is dried, ground, and shaped into a powder before being shaped into wafers. That truly is pretty neat.

When serving crabs, select the right size for your crab and give the meal a quick rinse.

Aquatic Plants

Some crabs are very interested in their aquatic plants if you have plants in your aquarium, and your pets might be curious about them.

My plants aren't chemically treated, so crabs will be able to eat them.

You can be sure to find an aquatic plant suitable for a marine aquarium. If you observe unusual behavior in your crabs due to eating underwater plant leaves, you shouldn't further feed them.

Lean Meat

You can supplement the crabs' diet with lean meat, such as beef or chicken. The activity is that there are numerous options for serving these meats, such as you can simply serving them raw, cooking them in a pan briefly to kill any parasites, or steaming them.

Remove the bones from the meat before serving it to your crabs, and be mindful of this not constituting a whole portion of their diet. While it's a great way of supplying them with much-needed protein, you should not over-incite them to consume it, as it's inefficient for hauling fuel.

Like any other meat, be sure to purchase it from your local grocery store or butcher so you can ensure that there are no chemicals on or near them. Also, remember that if you're cooking the meat, ensure you do so thoroughly. Undercooked or raw meat can carry parasites that are harmful to your crabs!

Unsweetened Cereal

Even if your crabs aren't technically a food source, their favorite treats might be cereal! You'll find quite a few various varieties of this type of food available throughout most grocery stores, but be sure not to buy grains that contain added sugar.

Make sure to first offer them cereal that contains whole-grain wheat or bran, and the grain is unsweetened. In my experience, most crabs will eat until they no longer detect cereal smell in the water.

Other options include rice and puffed popcorn (unseasoned), and you could even provide your crab's PCA calcium.
Crabs construct their exoskeleton out of rigid but porous calcium ions. If you do not supply your crabs with the correct amount of calcium, their skeletons won t grow and develop normally, and if severe conditions occur, the crabs can even lose some or all of their limbs!

Some good sources of calcium include a coral-based substrate, eggshells (including the shells themselves and the white portions), oyster shells, cuttlebone, and other types of calcium-rich rock or mineral. Animal bones benefit from being crushed before using.

Like some other things in your crayfish tank, it's most effective to purchase most of these items from a trusted pet store so that you know they weren't treated with harmful chemicals. Otherwise, purchasing them online will provide you considerable variety in pricing and where you get them!

Final Tips

To keep your crabs healthy, you must always feed them various foods. Don't feed them the same food all the time, and remember that they should eat anything at all, except for prohibited things (including chocolate and other hazardous foods).

Make sure your crabs find comfortable hiding places that are appropriate for hiding from snails and other predators, just as with humans. Your crabs glom on the most pleasing areas, which is why you should do your best to make their environment as comfortable as possible for them.

Remember that crabs are filter feeders, so they don't need to eat daily. But instead, the survival of crabs depends on the quality of the food they've eaten in the past. Providing them with a balanced diet will provide you with solid and healthy pets.


We hope you have really enjoyed this article about what crabs eat! Crabs are fascinating animals that can be kept as pets. We recommend giving them a try if you're looking for a new pet. Always research your exact type of crab before the acquisition, so you can be mindful of their specific requirements.

Have we found this article to be helpful? If you've any questions or updates, just leave them in the section below. We will get back to you as soon as we can! And, if you found this article to be helpful, then please help us out by sharing it on social media! See you next time, and best of luck with your crabs!

Post a Comment for "What Do Crabs Eat In Fish Tanks?"