Found some info about the peacock shrimp, or the peacock mantis shrimp as you said roberta.
The latin name is odontodactylus scyllarus, here is an image of this absolutely stunning animal:
I was writing from what I remembered earlier, so I found out that it doesn't use two of its claws to make these vaccum bubbles, rather a hammer-like claw that can strike with forces thousands of times its own body weight. Even capable of shattering bullet proof glass!
Each hammer strike is followed by the collapse of the cavitational bubbles, which creates an additional explosion that might prove to be even more powerful than the impact itself.
O. scyllarus has more colour pigments in its eyes than found in any other animals, a whopping eight pigments. In comparison humans only have three. These eight pigments, in addition to some other traits, gives O. scylliarus the best colour sight in the animal kingdom. It also has two 'sets' of eyes, which makes it capable of seeing polarized light. I'm not really sure what polarized light is, but it sure sounds cool. :wink: