Mantis Shrimp

Most mantis shrimp species are moe colorful than
this.

Mantis shrimps are also known as Stomatopods and they are often introduced involuntarily to reef aquariums with live rock. The mantis shrimp hides in the rock and is thereby brought into the aquarium. This can be a problem since mantis shrimps are ferocious predators capable of attacking preys larger than themselves. A common way to discover that a mantis shrimp has been introduced is actually that fish and other reef life start disappearing from the tank.

The mantis shrimp is equipped with a special growth that it will use to impale its victims and it can also deliver devastating blows with its claws knocking the prey unconscious or even into pieces. The power in their claws is another problem for aquarists since these shrimps are strong enough to break aquarium glass with their claws. It is said that the Californian mantis shrimp can break double security glass and that their attack is as powerful as a 22 calibre bullet.

As you might have guesses already, the mantis shrimp is often considered a pest and many aquarists try their best to catch and remove it from their aquariums. These shrimps can however, as more and more aquarists discover, be fascinating aquarium inhabitants if one gives them their own acrylic aquarium to live in. Never try to keep a mantis shrimp in glass aquariums or in a community tank.

Mantis shrimps are not only fascinating pets they are usually also very beautiful creatures. Add to this the fact that they are very hardy compared to most other saltwater creatures which makes them an ideal choice for those who are just starting to keep saltwater aquariums. In fact, mantis shrimps are often referred to as sea cockroaches due to their hardiness and adaptability.  

Mantis Shrimp Aquarium

If you want to setup an aquarium for a mantis shrimp you should start by getting an acrylic aquarium, because the shrimp can't break an acrylic tank the way it can break the glass in a glass aquarium. It is recommended that you let the aquarium stand empty at least a day before putting the mantis shrimp into the tank (preferable longer but one might not want to leave a newly discovered mantis in another tank any longer than one have too.) Make sure to prepare the water by removing ammoniac, metals etc before introducing the shrimp. The salinity should ideally be kept around 1.022 and the temperature around 24-28°C / 75-82°F. Decorate the aquarium so that the mantis shrimp has a lot of caves, nooks and crannies to hide in.

You will need to change about 25-35% of the water in your mantis aquarium every two weeks. You will also need to replace water that has evaporated on a regular basis to keep the salinity level stable. It is recommended to check the salinity at least twice a week and regulate the level if necessary.  You might have to change water more often if the water quality deteriorates. Feed your mantis shrimp small fish, shrimps, worms and other meaty food. They usually accept almost anything meaty they are presented with. 

How do I know if I got a mantis shrimp in my tank?

I am sorry to say that the most common sign of a mantis shrimp in an aquarium is that fish starts to disappear.  With a little luck you might however be able to find the shrimp before it starts consuming your fish.  If you hear strange knocking sounds from your tank at night there is a real chance/risk that a mantis shrimp have been brought into the tank. The sound is the mantis shrimp knocking on the coral while hunting.

Moving/removing the mantis shrimp

The best and most secure way to remove a mantis shrimp is to remove all coral from the aquarium during daytime and locate the shrimp. The shrimp will be hiding somewhere among the live rock during the day.

If you don't want to remove all the rock (it can be quite a daunting task) you can use a mantis shrimp trap instead. It can however take several days or even more before the shrimp falls for the trap and by then it might have killed several more of your precious fish and sea life. Mantis shrimp traps can sometimes be hard to come by, especially in smaller towns and cities. They are however available online and can be ordered to your home. This might however not be an attractive solution if you already have a mantis shrimp wrecking havoc in your beloved tank. 

A third way to remove mantis shrimp is to lure them out using bait and then catching them when they go for the bait. They are however very quick so you shouldn't be surprised if this method fails and the mantis shrimp takes the bait and retreats again before you get a chance to catch it.