 Hammer and Lance
While vertebrates mostly rely on teeth and claw to subdue prey, invertebrates possess a most impressive array of weaponry, each deadly in a different way. From the nail-tipped tentacles of large squid to snapping mandibles of a trapjaw ant, from poison-tipped, launchable harpoon-teeth of cone snails to the eversible, elastic stomach of starfish, invertebrates utilize countless bizarre ways to hunt. However, to me, one animal stands above all others with abilities more suited to war machines than a small shelled critter. The creature is named mantis shrimp, and the reason it is impressive shall be the topic for this week's column.
The humble mantis shrimp is a rather small, lobster-like animal. Its front legs take the form of a pair of claws, which it holds close to its body, indeed resembling a mantis in that stance. Some are flamboyantly colored, with bright reds and greens, yet others are fluorescent. Despite being easily visible, few predators dare to attack it - the reason lies in its claws.
There are two forms of claws, spearing and smashing types. Both can strike in a blink (Wikipedia gives 23m/s and compares the claw with a bullet) and pierce through flesh or crush glass. The strike generates shockwaves in its wake, which can kill prey from a distance. The strike also generates light and heat (the latter comparable to the surface temperature of the sun) as the cavitation bubbles formed by the claw collapses, though this doesn't affect the animal's hunt as the actual effects are not significant.
As mantis shrimps need to aim their claws, good vision is expected, though nature went overboard with the eyes as well. Humans generally have four photoreceptor types for vision. Mantis shrimps have at least sixteen and see well into ultraviolet as well as infrared. The eye is further divided into three regions, each acting in a way as a separate eye. There are also regions specializing in certain wavelengths of light, making the mantis shrimp eye rival complex camera arrays.
In addition to their frightening sensory arsenal and weaponry, they're also smart. Their bright colors and fluorescence allow them to recognize one another and communicate, even recognizing those they have met before. Some species are monogamous and show parental care. They are also famous for their tenacity in aquariums, especially when they're unwelcome (many can sneak inside a coral), earning them the nickname "roaches of the sea".
Long story short, if mantis shrimps ever try to take over the Earth, I know which side I will be supporting. Humans have no chance.
BY ALPER ÖZKAN (MBG/III)
d_ozkan@ug.bilkent.edu.tr
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