What Is Emerald Crab Lifespan? How To Take Care Properly?

Interest in crabs in aquariums has increased over the past decade. One of the most heavily traded crabs in the ornamental fish industry is the Emerald crab. They are known for their ability to control nuisance algae, algae cleaning crew. While they can be very beneficial to keep in your tank, the question is, what is the emerald crab lifespan?

This article will discuss emerald crab lifespan in depth and how to properly care for emerald crab so that they can stay healthy and live as long as possible.

See also:

  1. What Is The Emerald Crab Max Size? Interesting Facts.
  2. Top 5 Cute and Fun Facts About Saltwater Hermit Crab Eggs.
  3. Can Hermit Crabs Live Out of Water? (Impressive Answers).

What Is Emerald Crab Lifespan?

Typically, the life span of a emerald crab is between two and four years. It’s not that they’re the longest-lived invertebrates, but they’re still better than most cheap cleaner shrimp.

As always, there is no guarantee as to how long one can expect to live. In the end, crabs are dependent on the environment in which they grow and the care they receive from you.

It is very important that you maintain the tank properly as well as feeding the crabs a healthy diet. The lifespan of your crabs may be dramatically shortened if you do not take proper care of them.

How To Take Care Of Emerald Crab Properly?

When living in the right conditions, these crabs are quite self-sufficient. That said, you can’t trust them to take care of everything! You must do your part to provide a healthy environment where they can thrive.

Here are some guidelines to help you know to take proper care of them.

Tank Size

It is recommended that each Emerald Grab be kept in a tank that holds at least 20 to 30 gallons of water.

Even though these crabs can live in small tanks and thrive in large ones, they do still require a little bit of scavenging space to survive. In cramped quarters, Emerald crabs can become very territorial.

Water Parameters

Almost all standard coral reef tank and marine tank configurations work well with Emerald crabs. However, they also have some preferences which they follow when choosing tank.

Warm waters are ideal for the crabs, since they live in shallow waters in the wild. It is also best for them if the pH level of the water is more on the alkaline side.

If you want good results, make sure that the water quality is near the following.

  • Water temperature: 72°F to 82°F (above 75 degrees is best)
  • pH levels: 8.0 to 8.4
  • Water hardness: 8 to 12 dKH
  • Specific Gravity: 1.020 to 1.025 (around 1.023 is ideal)

What To Put In Their Tank

Kind of environment emerald crab like should have live rock
Kind of environment emerald crab like should have live rock

The emerald crab lives in rocky areas teeming with life, and this is the kind of environment they prefer. In order to make your crabs as comfortable as possible in captivity, it is recommended that you recreate this natural environment as closely as possible in their aquariums. First, a sand layer should be laid down. You can then arrange live rocks.

If emerald crabs are introduced to the tank for the first time, they are primarily nocturnal animals. The majority of the day will be spent hiding in crevices and caves.Eventually, your chances of encountering them at daytime will increase as they become more familiar with your tank. Don’t remove those rocky outcrops, though. They are still important for your crabs to hide

Algae on rocks is also able to accumulate, turning it into a valuable food source for the animals. There’s no need to add coral, you can do so if you want to create a more beauty. Adding some other simple plants is also good. Crabs can eat organisms that live on the leaves of plants.

Food & Diet

Emerald crabs are very easy to feed. Emerald crabs are not picky eaters. They always have an appetite and can consume most foods.

Not all aquarium cleaners will eat algae. But this species is known to eat algae, like bubble algae and hair algae. In addition, they also eat detritus and other edible creatures

You may even see them nibbling on food that collects on their leg hairs!

If your tank does not have enough algae to feed them, provide supplemental foods such as dried seaweed, commercial pellets and chopped shrimp, … in its diet

The most important thing you could possibly do for your crabs is to make sure they are well-fed, or else they may turn to their tankmates to eat.

Do emerald crabs kill fish?

The emerald crabs will not attack and kill fish, thay are incapable of catching a fish that is healthy.

Will emerald crabs kill each other?

Emerald crabs have a strong tendency to get aggressive with other crabs. For that reason, if you have a small tank, it would be better to only have one crab or a pair of crabs that are of the opposite sex.

What are Emerald crabs compatible with?

You can place emerald crabs in the tank with most kinds of fish and invertebrates. This means that, as long as you provide them with food sources, these crabs should not bother any fish, invertebrates, or coral in your aquarium.


In conclusion, Emerald crabs live for two to four years in the wild, but they have the potential to live a few more years captively, such as in an aquarium or marine tank with proper care. You must take care and provide the best conditions, care for them to live healthy and long lives. We hope you enjoyed this guide and feel more prepared to own an emerald crab in your home tank!

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