I can't really tell but it looks like a tiger pistal shrimp I have 2 of them in my 55gal. My experience with pistal shrimp is once they find a rock to live under they pretty much stay their. Your not going to see the pistal walking around the tank looking for fights. They are very cool to watch so I recommend getting a goby to see them in action. A pistal shrimp is not itself without a goby and a goby is not them self with out a pistal shrimp. I can never wait around and see if they pair up on their so I usally help the goby find the pistals burrow. So if you were to put the pistal in your tank once he is settled in try to get a watchmen or a high-fin goby. (High-fin gobies are more active then watchmens) I've had 4 pistal shrimp and they all matched up pretty easy. If you buy a goby try to put him in right next to the pistal for a easy meetting. You might here a few clicking sounds. I should also add I had to pay $20 a piece for mines and sometimes you can't find them for months.