14 replies to this topic

[Grayscale]

Hi.

Found this link on a diveforum, and thought some here might want to see it. Think it's new to this forum since I couldn't find it while searching...

16min41sec

http://www.ted.com/t...st_animals.html

Edited by Grayscale, 14 June 2009 - 01:43 PM.

[JTemple]

And know we know exactly how and why they can break a dome port!
Cool stuff, thanks for posting that.

[sgietler]

hey, did a Mantis shrimp break your dome port?

[JTemple]

Not mine. But I've heard it has happened.

[bmyates]

Great link! Also explains why one of their nick-names is "thumb-cracker" - can you imagine reaching for one?!?! OUCH!

[JackConnick]

Supposedly hits with the speed and force of a .22 cal bullet.
Jack

[drsteve]

Supposedly hits with the speed and force of a .22 cal bullet.
Jack

Well, according to the presentation the snapping speed is 20m/s. A .22 caliber bullet goes 330 m/s. The mantis shrimp, while fast, is no bullet. Similarly, I am pretty sure that a .22 cal bullet has quite a bit more energy behind it. The mass of the .22 caliber slug is between 2 and 4 grams. I don't know what the mantis shrimp smasher arm weighs, but I would be very surprised if it was this much especially since it isn't made of lead. The energy expended is 1/2 m v^2 and since both the bullet mass and velocity are higher than the shrimp, it is pretty clear that the bullet wins on all counts. Still the mantis shrimp is a very impressive creature. I really enjoyed the lecture and loved the info about the induced cavitation bubble that creates a second strike.

Another fun fact about them is that while humans have three different types of color sensors in our eyes (which gives us a three dimensional color space i.e. RGB), the mantis shrimp has 7 distinct color sensors which gives it a 7 dimensional color space. It can distinguish between many colors that look identical to us. In other words we are all extremely color-blind compared to the shrimp!

Edited by drsteve, 16 June 2009 - 10:18 PM.

[reefnet]

Another fun fact about them is that while humans have three different types of color sensors in our eyes (which gives us a three dimensional color space i.e. RGB), the mantis shrimp has 7 distinct color sensors which gives it a 7 dimensional color space. It can distinguish between many colors that look identical to us. In other words we are all extremely color-blind compared to the shrimp!

In many ways, the mantis has the world's most complex eye. Have a look at the article "Mantis Shrimp Eye Structure and Function" at http://scubageek.com/ .

Les

[Stephen Colquitt]

Very interesting video!

[Cal]

Awesome vid!!

"Well, according to the presentation the snapping speed is 20m/s. A .22 caliber bullet goes 330 m/s. The mantis shrimp, while fast, is no bullet. Similarly, I am pretty sure that a .22 cal bullet has quite a bit more energy behind it. The mass of the .22 caliber slug is between 2 and 4 grams. I don't know what the mantis shrimp smasher arm weighs, but I would be very surprised if it was this much especially since it isn't made of lead. The energy expended is 1/2 m v^2 and since both the bullet mass and velocity are higher than the shrimp, it is pretty clear that the bullet wins on all counts"

- I think the old "mantis vs bullet" idea came about because the mantis shrimp is underwater where its exerted force meets such heavy resistance. So above water the movement rate would be a great deal faster - No idea if it would be bullet fast though.

They've also been known to break aquarium glass on a number of occasions!

Cal

[ce4jesus]

That was cool but I thought that the 22 analogy was for another crustacean that snapped its claw together creating a percussion which would render pray unconscious.....can't recall the name though.

[Tjsnapper]

Really interesting, thanks for posting

[jonhanson]

Interesting video. I also liked the scuba geek article.

[S.Honig]

That was cool but I thought that the 22 analogy was for another crustacean that snapped its claw together creating a percussion which would render pray unconscious.....can't recall the name though.

I think you were thinking about pistol shrimps

http://en.wikipedia.org/wiki/Alpheidae

[melia01]

WOW that video presentation is incredible! great science!