yeah.. hope he's all right.. and also that he's legal.. he
should be covered by insurance...
wow.. the mantis shrimp bashed the crab so hard the crab
shattered 
and there are 2 hits... the impact of the club and a cavitation
bubble which shockwave causes a whole world of hurt!
Hmm.... cavitation bubble....
For that to occur, the shrimp's limb had to be moving so fast
that the pressure in the water flow surrounding the limb would drop
below the vapour pressure, allowing for dissolved (cavitation)
bubbles to come out of the solution.
When cavitation bubbles collapse, very high local temperatures
and pressures can result.
In extreme cases, they can damage turbines and impellers..... in
less extreme cases, cavitation bubbles are in fact used in
ultrasonic cleaning equipment.
