Crysomallon squamiferum, commonly known as the scaly-foot gastropod, was discovered in 1999 in the Kairei "black smoker" field on the Central Indian Ridge, at a depth of 2420 metres.
Christine Ortiz at the Massachusetts Institute of Technology and her colleagues studied the snail's three-layered shell to find out how it defends itself from crab attacks.
To assess the shell's strength and stiffness, they penetrated it with diamond-tipped probe – applying the same amount of force that an attacking crab's claws might use. They then used the data to model the shell's layers and launched a virtual crab attack on it.
Iron hard
It turns out that the snail employs some unique tricks to protect itself. For example, the shell's outermost layer consists of strong particles of iron sulphide created in the hydrothermal vents, each around 20 nanometres across, embedded in a soft organic matrix secreted by the snail. This structure is designed to crack when hit, but in a way that absorbs energy.
Cracks spread only by fanning out around the iron sulphide particles. This "microcracking" not only absorbs energy, it also ensures that larger cracks do not form. What's more, the particles of iron sulphide may blunt and deform intruding claws, the study suggests.
0 comments:
Post a Comment