[StirCrazy]

Originally Posted by justinl

steve, the species seen in the video is Lysiosquillina maculata, a spearer. It isn't capable of cavitation. It could still do major damage witth those great big sharp raptorial appendages and spined telson though.

If the mantis in question were a smasher, still no cavitation would occur. the claw is a small enclosed fixed volume space. No cavitation will occur within the claw or outside it because air is too thin to form such a steep pressure gradient. The claw may still be damaged simply due to the extreme forces the muscles exert on it. The damage would likely be severe if the animal had just moulted, but would also be more reluctant to strike as well. My guess is that the animal was freshly moulted or very unhealthy.

actualy lots of things are capable of producing cavatation.. smashers do, my point was the discription of cavitation on the page with the video.. it is back wards. cavatation forms in a low pressure zone where the entrained gases in the water come out of solution and form a air bubble, then when the pressure returns to normal the bubble colapes upon its self causing quite a powerfull implosion in a relitive scale. if anyone has a boat and dinged the propeller a timy bit this disrups the flow across the blade and creats a low presure zone which inturn causes cavatation. left long enough you get what is called cavatation burn which looks like streaks of rust, then eventualy it burns little holes in the blade. this can also be caused by operationg a propeller outside of its design preamiters. this is also a common ocurance in diesel engins around the cylinder liners which is why there is an anti cavitation additive added to diesel antifreeze. but I digress.

it has been documented that a smasher will cause cavatation on a strike, I simply was stating that what the guy posted was wrong as it is created behind the strike not infront of it so there can be no implosion dammage to the prey. I would be willing to bet a spearing type mantis would be able to create cavatation also, unless there apendages are naturaly shaped to prevent it which would mean if it had a dammage edge on its apendage then it could produce cavatation other wise no.

Steve