In the list of reef dwellers, crabs are frequently ignored by beginners for saltwater aquariums. However, their advantages cannot be understated. Crabs are decapod crustaceans, found across every ocean in the world. There are many reef-safe options that are suitable for every level of experience of saltwater tank owners. Depending on the species, they have a variety of diets and can be incredibly vivid and a fascinating addition to any saltwater tank.

Should I Be Considering Adding Hermit Crabs To My Aquarium?

If you’re struggling to manage the algae in your aquarium, or if you’re thinking of bringing more interest and color to your set-up, then hermit crabs could be the ideal solution! Hermit crabs have been essential reef additions for many years as aquarists are searching for more time-efficient, affordable, simple and natural ways to keep up with tank upkeep. Hermit crabs are omnivorous scavengers, meaning they’ll clean up any leftovers that have fallen down to the bottom of your tank. Additionally, because of their compact size, they can really dig into all the small crevices within your rocks and corals to completely clear out any algae lurking to take over your tank. Their behavior is also fascinating to watch as they move their portable home around your tank. Our favorite reef safe options include the Blue Leg Hermit Crab (Clibanarius tricolor), the Mexican Red Leg Hermit (Clibanarius sp.) and the Scarlett Leg Hermit Crab (Paguristes cadenati).

Popular Saltwater Crab Species

Blue Leg Hermit Crab

The Blue Leg Hermit Crab (Clibanarius tricolor) is a colorful and reef-safe addition to every saltwater reef tank as it is an incredibly successful detritus eater that helps to extract unwanted food and waste from your aquarium. It is also very effective in moving into live rock crevices and eating algae and cyanobacteria. Named after its vivid and vibrant red-banded blue legs, the blue leg of the hermit crab has claws of similar size, finding its home in abandoned snail shells.

Scarlet Leg Hermit Crab

There are quite a few crabs that are perfect for keeping on top of your hair algae in your marine tank, particularly the Scarlett Leg Hermit Crab. This crab is easy to look after and a peaceful species of hermit crab. It’s reef-friendly and popular with a lot of aquarium hobbyists because it doesn’t ask you a lot, but it gives you so much back! When introduced to a healthy saltwater tank, this animal will need minimum care from you as long as they have the food they need and a large selection of shells that they can grow into.

Left-handed Hermit Crab

The left-handed hermit crab is another lovely crab and a very fascinating species! This form of hermit crab is renowned for possessing a huge left claw. This claw is used to shield the entrance to the shell of the crab as it is concealed within. It is the second-largest family of hermit crabs, with over 400 species of species distributed all over the world. It’s a very common choice for inexperienced hobbyists, as they are docile and hardy crustaceans. They’re good to have in the coral reef, too. Growing up to an inch, these crabs are also known as zebra hermit crabs, whose legs have black and white stripes.

Emerald Crab

Their dark green exoskeleton is extremely eye-catching, and they’re wonderful to look at. They are really hardy crustaceans, too, and they can be kept content easily enough. As long as they have enough food to eat, these crabs are happy and peaceful. If you’ve got problems with bubble algae, these are the crabs to go to because they love the slimy stuff! Bubble algae can be difficult to work with, so it’s nice to get a helping hand (or a pincer). Emerald crabs don’t grow too large and are docile, seldom disturbing other fish or invertebrates as long as they have enough food.

Porcelain Anemone Crab

The Porcelain Anemone Crab is one of the first to pop to mind for aquarium lovers. Beautiful, vibrant, and useful – they will make a perfect addition to a lot of saltwater tank setups. They are versatile, robust and low maintenance and are a joy to take care of. The Porcelain Anemone Crab (Neopetrolisthes maculatus) are native to Indo-Pacific waters but are now commonly known as ‘aquarium regulars’ all over the globe. They have a distinctive red polka dot pattern on a bright white shell body. They have one of the most unusual habits of feeding in the aquatic world, which makes them very interesting to watch.

Saltwater Crab Care

When you want to introduce hermit crabs to your aquarium, you need to make sure that there are larger shells in the tank, so that they can step in when they’re ready. You can give them a number of shells, since often these crabs can be picky. This will freak the crab out, and they could be hostile against other inverts in the tank, attacking them for a home. You can order twenty, fifty, or a hundred empty shells to make sure you’re well stocked!

These lovely coral dwellers are easy to take care of. They don’t have a particular diet, and they feed on tiny bits of frozen Shrimp Reef Roids that feed your food. When these floating bits are settled, the crabs will munch them up. Just note to add a little extra feed when you’ve got crabs.

The majority of hermit crabs are typically reef-safe, but if algae amounts (and other food sources) are inadequate, this opportunistic feeder can be used to steal food from sea anemones and other tank mates. If there is insufficient algae, make sure to add dried algae or other quality pellet fish food to your diet. Be sure to research the compatibility of adding crabs to your tank as well as their specific tank requirements for each species. 

We always love to see your reef aquariums, especially with beautiful additions such as Zoa corals! Don’t forget to send us your pictures via our website here, or find us on Facebook, Twitter and Instagram!