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imcosmokramer
02-23-2010, 10:12 PM
This guy is out of his mind... I don't care how much he's done this before

http://reeftools.com/news/holding-a-zebra-mantis-shrimp/
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Zoaelite
02-23-2010, 11:28 PM
Wow after hearing all of the horror stories about people having there fingers cut off while collecting wild coral I don't see this being a smart idea. Then again they are extreamly smart inverts so who knows :neutral:.

StirCrazy
02-23-2010, 11:45 PM
neat video, needs to read up on cavatation a bit though, it can't forma bubble between the claw and the surface being struck as this is a high pressure zone, the bubble would actualy form on the back side of the claw and whould implode when the claw stopped moving fast enough to maintain the low pressure zone behind it. the effect of the implosion would affect the claw of the mantis more than the prey, but there could be some sound wave generated that might be able to stun suseptable prey.

Steve

PACMAN416
02-23-2010, 11:46 PM
wow, intense!! I would not be able to do that as I would fear my finger getting chopped off!:laluot_14:

PACMAN416
02-23-2010, 11:48 PM
FYI stircrazy, your website Island Aquatics (http://www.islandaquatics.ca/) doesnt work

globaldesigns
02-23-2010, 11:57 PM
Not a very smart person. He will get it one day...

RuGlu6
02-24-2010, 12:10 AM
This guy is out of his mind... I don't care how much he's done this before

http://reeftools.com/news/holding-a-zebra-mantis-shrimp/

How about this...
What if Mantis just recently dropped his old exoskeleton and new one is still soft?
There is no way to tell for sure but Mantis will not strike in times like these.

StirCrazy
02-24-2010, 12:13 AM
FYI stircrazy, your website Island Aquatics (http://www.islandaquatics.ca/) doesnt work

yup, I know.. it is under construction anyways.. one of these years I may finnish it...

justinl
02-24-2010, 12:46 AM
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.

superduperwesman
02-24-2010, 12:50 AM
Crazy!

bignose
02-24-2010, 01:28 AM
That guy is insane! I wonder if he did research before buying that shrimp? He will (or my have) learned his lesson the hard way:lol:

viperfish
02-24-2010, 03:09 AM
If the mantis in question were a smasher, still no cavitation would occur..

Smasher type Mantis Shrimp such as Peacocks certainly do produce enough velocity in their strike to cause cavitation. http://imladris.bio.umass.edu/biology/pateklab/extreme-impact-and-cavitation-forces-biological-hammer-strike-forces-peacock-mantis-shrimp-odontodac

StirCrazy
02-24-2010, 04:18 AM
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

imcosmokramer
02-26-2010, 12:24 AM
I think either way, spearing or smashing, I'd rather keep my hands out. It may have just molted also
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ScubaSteve
02-26-2010, 01:47 AM
So, I guess this is how people frag finger coral?