Stomatopoda (Mantis shrimp)

Mantis shrimp (Stomatopoda) have an interesting way of hunting their prey whilst also sometimes being very pretty, making them a very interesting animal. 

There are two types of Mantis shrimp:

"Smashers":
Will crush even the hardest of shells of various invertebrates, but will also occasionally go for fish.

To give them the opportunity to break some shells, try feeding them raw crustacean which have a hard shell. 

They may hit the aquarium's glass as a way of extending their cave. By placing plexiglass on the bottom of the tank, and ensuring their cave is not placed next to the sides, one can eliminate this problem. 

Smashers live in caves between the rocks, but they may also dig into the sand.

"Spearers":
Have very long barbed arms, which they use to catch softer prey, like fish for example.

As they live on the bottom of the tank, the substrate must be deep enough to accommodate the Mantis' size. 

What they both have in common is that unless one buys a very small species, they will often require a dedicated aquarium. When attempting to keep them with other fish one should know that the larger species will eat most of the other animals in the tank. 

Mantis shrimps should be fed every couple of days, and will only eat when hungry.
Their food should be varied and enriched with omega-3 and vitamins. They are not usually choosy about their food, and can be fed all types of raw seafood. 

After changing their shell, they will often hide and refuse to eat for about a week. 

Read more about the many different species here.