Reef Safe Crabs

When you are picking out reef safe crabs, make sure you know what species you are getting. Many different types of crabs will attack and eat other crustaceans and invertebrates. Some grow very large and will even attack your fish. Buyer beware is the order of the day.

Crabs are scavengers and will eat most any kind of algae and leftover foods they can find.

The ones I will mention here are thought to be reef safe. Just remember, each animal is different and may behave differently.

The emerald green crab is one of the best reef safe crabs you will find. These guys will chow down filamentous (hair) and Valonia (Bubble) algae.

He has a bright green body with somewhat hairy legs. Both front claws are the same size. I’ve read that they can grow up to three inches, but I have never seen one bigger than 2 1/2 inches.

They are constantly active, searching your live rock and substrate looking for algae or leftover food to eat. The fact that they eat the dreaded bubble algae is reason enough to include them in your cleanup crew.

How many you should have in your reef? I would say, only one.

The Sally Lightfoot crab, also known as the Nimble Spray crab, is a pretty good candidate for your reef. Their diet consists of many kinds of algae as well as meaty items that can be found in your aquarium. Mine even ate some bubble algae that started to appear in my nano tank.

He has a brownish body with orange/yellow rings on the legs. His carapace (body shell) is really flat, so he is able to crawl into small crevices between rocks. Mine reminds me of a spider, the way he walks.

The maximum size for the Sally Lightfoot is around 3 inches. It has been reported that they can be semi aggressive when they get big. Mine is almost full grown and he is not the least bit aggressive.

Like all crabs, he is a scavenger and will search your tank for any scraps he can find. At feeding time he is not shy and comes right out to get his share of food.

These are my picks for reef safe crabs. There are many more crabs to choose form. Just make sure you do your research before you buy one.