Shrimpy superboxer
by Jonathan Sarfati
Published: 28 June 2006 (GMT+10)
This is the pre-publication version which was subsequently revised to appear in
Creation 30(2):12–13.
For pound-for-pound boxing records, look not to ‘Sugar’ Ray Robinson
or Rocky Marciano. Rather, the 6–10 cm (4–6 inch) long mantis shrimp
or stomatopod has the fastest punch of all. Crustacean1
expert Shiela Patek and her team at the University of California, Berkeley, needed
high-resolution video at 5,000 frames per second to analyse this.2 They showed that the peacock mantis shrimp (Odontodactylus
scyllarus) can punch with a force ‘well over a hundred times
the mantis shrimp's body weight.’2
The club-like limb reaches a top speed of 14–23 metres per second (31–51
mph), and a peak acceleration of 65–104 km/s2 (6600–10,600
g, where 1 g is the acceleration due to gravity; astronauts and jet fighter pilots
will pass out at only 10 g).3 They
use this to crush the shells of snails they prey on, and in captivity, have shattered
the glass walls of their tanks.2
Catapult
To reach such speeds, ordinary muscles won’t do. Rather a catapult mechanism
is required—that is so lots of energy can be built up in an elastic material, then
released suddenly. Thus the shrimp has a specialized saddle-shaped spring in the
hinge of the shrimp’s striking appendage.
The peacock mantis shrimp can punch with a force ‘well over a hundred times
the mantis shrimp's body weight.
Its shape has the technical name hyperbolic-paraboloid, but resembles a
Pringles chip. It is a very strong and efficient structure. Indeed, it is used in
engineering and architecture because it distributes stresses and resists buckling,
while the nautilus uses this structure to strengthen its shell.1
However, no other animal uses it as a spring.3
But a spring isn’t enough for a catapult. There must also be muscles to load
it, and a click or latch mechanism to release it. If all these parts were not in
place, the mechanism would not work at all. This could not have formed by random
small changes and natural selection, because the latter would not work since the
changes confer no advantage until the whole system is complete.
Bubble blast
In fact, each blow is a one-two punch. Dr Patek’s team found that there were
two force peaks for every strike, less than half a millisecond apart. The second
one is caused by a destructive process called cavitation.4 This is where high-speed water flows irregularly,
causing tiny bubbles of water vapour to form. When the pressure is restored, they
collapse at supersonic speeds, forming shock waves with huge pressures, as well
as sound and even light. In fact, the cavitation forces may be almost four times
those of the actual limb impact. Cavitation can destroy steel surfaces and boat
propellers, and would have destroyed hard rock during the Flood.5 Even the shrimp’s heel is not immune—even
though it contains tough minerals, they moult frequently to regenerate.3
Chance or design?
Instead of throwing a shrimp on the Barbie, I want to put a prawn into space.
The mantis shrimp with the catapult puncher that exploits cavitation defies evolution.
But how does crushing snails fit with a creation described as ‘very good’?
First, invertebrates such as snails are not ‘living’ in the sense of
being ‘soulish’, as vertebrates are #8212; the Bible never calls them
nephesh chayyāh (Hebrew נֶפֶשׁ
חַיָּה living souls/creatures). Indeed,
scientific evidence suggests that invertebrates do not experience pain.6 Second, this could have been a latent feature programmed
into the genes by the Creator who foreknew the Fall.7
Super sight
The mantis shrimp also ‘has one of the world’s most complex colour vision
systems’, according to Justin Marshall of Queensland University’s research
centre for vision (Australia).1 While
humans have three different types of colour receptor (red, green and blue), the
shrimp has 12. Four of these can see in the ultraviolet, which we can’t.2 Furthermore, they can tune their
vision with special transparent colour filters to compensate for the way water absorbs
different colours differently.3
Dr Marshall said that understanding the shrimp’s eyes could help us design
cameras for satellites. ‘Instead of throwing a shrimp on the Barbie, I want
to put a prawn into space.’1
Update, 26 October 2009: these eyes could also revolutionize DVD technology,
according to
‘Sexy’ shrimp eyes help DVD technology:
They can see in 12 primary colours, four times as many as humans, and can also detect
different kinds of light polarization — the direction of oscillation in light
waves. Now a team at the University of Bristol have shown how the shrimps do it,
using remarkable light-sensitive cells that rotate the plane of polarization in
light as it travels through the eye.
Manmade devices do a similar thing in DVD and CD players but they only work well
for one colour, while the shrimp’s eye operates almost perfectly across the
whole visible spectrum from near ultra-violet to infra-red. Transferring the same
multi-colour ability into a DVD player would result in a machine capable of handling
far more information than a conventional one.
“The mechanism we have found in this eye is unknown to human synthetic devices.
It works much, much better than any attempts that we've made to construct a device,”
said researcher Nicholas Roberts. He believes the “beautifully simple”
eye system, comprising cell membranes rolled into tubes, could be mimicked in the
lab using liquid crystals.
Details of the mantis shrimp research were published in the journal Nature Photonics.
References
- Prawn of a new era, Sunday Telegraph, 16 September 2001.
Return to text.
- Marshall, N.J. and Oberwinkler, J., The colourful world of the
mantis shrimp, Nature 401(6756):873–874, 1999; this
shrimp was Neogonodactylus oerstedii. Return to text.
- Cronin, T.W., Marshall, N.J., Caldwell, R.L., Tunable colour vision
in a mantis shrimp, Nature 411(6837):547–548, 2001;
this shrimp was Haptosquilla trispinosa. Long wavelength light such as
red is absorbed more than short wavelengths like blue, so very little red reaches
the shrimps in deep water, so its filters are tuned to shorter wavelengths.
Return to text.
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Related article
References
- Weston, P., Creation’s crustaceans,
Creation 23(3):10–13, 2001;
creation.com/crust. Return to text.
- Sanders, R.,
Mantis shrimp may have swiftest kick in the animal kingdom, UCBerkeley News,
www.berkeley.edu/news/media/releases/2004/04/21_shrimp.shtml, 21 April 2004.
Return to text.
- Patek, S.N., Korff, W.L. and Caldwell, R.L., Deadly strike mechanism
of a mantis shrimp, Nature 428(6985):819, 22 April 2004.
Return to text.
- Patek, S.N. and Caldwell, R.L., Extreme impact and cavitation forces
of a biological hammer: strike forces of the peacock mantis shrimp Odontodactylus
scyllarus, Journal of Experimental Biology 208:3655–3664,
2005. Cavitation is somewhat like boiling. Even non-boiling liquids have some molecules
escaping as gas, and some of these molecules return to the liquid. At equilibrium,
the gas has a certain vapour pressure. Boiling occurs when the liquid is
hot enough to raise its vapour pressure above atmospheric pressure. At high altitude,
it takes a lower temperature to boil because the atmospheric pressure. Cavitation
takes this a step further: the fast flow of a liquid lowers the pressure by the
Bernoulli effect, and when the pressure drops below the vapour pressure,
bubbles of vapour are produced. Shallow water is worse because there is less pressure
from the weight of the liquid. The damage is caused when the bubble bursts, since
the pressure of the surrounding liquid is very high for small bubbles (inversely
proportional to the radius). Return to text.
- As long as the water was fast (over 30 m/s, 70 mph) and shallow
(under 10 m or 30 feet deep); Cardno, S. and
Wieland, C., Clouds, coins and creation: An airport encounter
with professional scientist and creationist Dr Edmond Holroyd, Creation
20(1):22–23, 1997; creation.com/holroyd.
Return to text.
- ‘Some insects normally show no signs of painful experience
at all. A dragonfly, for example, may eat much of its own abdomen if its tail end
is brought into the mouthparts. Removal of part of the abdomen of a honeybee does
not stop the animal’s feeding. If the head of a blow-fly (Phormia) is cut
off, it nevertheless stretches its tubular feeding organ (proboscis) and begins
to suck if its chemoreceptors (labellae) are brought in touch with a sugar solution;
the ingested solution simply flows out at the severed neck.’ ‘Sensory
Reception: Mechanoreception’, Encyclopædia Britannica (Electronic
edition on CD). Return to text.
- See also Batten, D. (Ed.),
Catchpoole, D., Sarfati, J. and
Wieland, C., The
Creation Answers Book,
chapter 6, Creation Book Publishers, USA; and Q&A: Death
and Suffering, creation.com/curse.
Return to text.
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