coul this be a mantis?

[pomme]

i have had my tank for over 6 months now, and since i can remember i occaisionally get a 'crack' sound coming from the tank, it sounds like the tank glass is cracking. this at first time of hearing made me jump up and run over to the tank to make sure it was okay, but after doing this a few times i know its something in the tank now making the noise.

Today whilst looking at one of my acro colonies i saw this:
http://www.reefsuk.com/member_images/0314.jpg

http://www.reefsuk.com/member_images/0315.jpg

it has two bit claws at the fron and has bright white eyes, and is a green fluorescent colour.

Could this be a mantis or a pistol shrimp, or could i have a mantis and pistol?

sorry a bit lost about this.

andrew

[pomme]

i have been searching around and this seems to be what i have:

http://www.wading-in.net/Tank/Pistolshrimp.html

are these bad for the tank?

[slylie]

no pistol shrimps are pretty harmless. i have had one in my tank for a year.. never seen it, just hear it everynight

[Herbert T. Kornfeld]

pair it up with a watchman goby and the two will have a nice long life together...