This is one of the small mantis shrimps that we occasionally collect here in the Keys.  I believe it is Pseudosquilla ciliata, but I’m not absolutely certain.  The specimens we get are usually 1 to 2” long, but we also get them as large as 5” long (see the listing for large ones to get a big one if they are available).  This species of shrimp can vary in appearance quite a bit, from the more common lime green to a bright red to green with a white stripe.

 

Mantis shrimp are very aggressive and are usually reserved for a species only tank.  I would not recommend mixing them with any other fish, shrimp, crab, or thin-shelled snail.  I would also not recommend handling them.  For more information on mantis shrimp, go to Dr. Roy Caldwell’s excellent site dedicated exclusively to mantis shrimp.  Copy and past this link to go directly to this shrimp on his site. 

 http://www.ucmp.berkeley.edu/arthropoda/crustacea/malacostraca/eumalacostraca/royslist/species.php?name=p_ciliata