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’ 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
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.
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.
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
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—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
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.
Update, 24 January 2014: more recent research shows that the mantis shrimp are not especially good at fine distinctions in colour. It’s important to note that colour vision requires not only the right eye design to pick up light signals but also the brain to process these signals. Our own ability to discern different colours is the result of our brains processing the relative intensity of the signals from the three types of colour receptors. E.g. yellow light stimulates both the red and green receptors, which is why TV and computer screens can simulate yellow with tiny red and green pixels shining together. A small change in the shade results in a slightly different intensity ratio. This three-pigment system combined with brain processing enables very fine colour discernment.
The mantis shrimp eye is designed instead to identify only the basic colours, but to do so speedily and with minimal requirements on its shrimpy brain. Its 12 different photoreceptors are arranged in a sequence, and when the eye scans an object with a sweeping motion of its eyes, the image will be picked up by different receptors that will respond differently. The colour is determined by the sequence of responses instead of intensity comparisons.
All the same, this is still an intricate design, and Dr Marshall says “I tried to convince NASA that they designed satellites wrong and should be using the [mantis shrimp] design for their sensors.” He also thinks it could be good for DVD technology. While normal DVDs use a red lasers, and Blu-Ray disks use a blue laser, “Mantis shrimp could inspire a ‘rainbow ray’ disc, where information can be packed into the entire spectrum. It would allow a lot more data to be stored in the same amount of space.”3