SHELLSThe bodies of some creatures are protected by strong shells. They include all kinds of animals ranging from crabs to armadillos, but the most well known are marine molluscs such as winkles, cockles, and clams. These animals absorb chalky minerals from their food or sea water and turn them into beautiful, sculptured, often vividly coloured “seashells”. These are sometimes lined with iridescent, gleaming mother-of-pearl.
Spines are as sharp as needles, and break off easily if they pierce another animal
1
NAUTILUS
A relative of the octopuses, with big
eyes and up to 90 tentacles, the nautilus can retreat into its pearl-lined shell for safety. The inner chambers of the shell act as flotation tanks.^2
VENUS COMB MUREX
Named for its comb-like appearance,
this sea snail of the tropical Indian
and Pacific oceans has up to 100 sharp spines that protect it from predators
such as shellfish-eating rays.^3
PAPAL MITRE
This is one of about 800 known species of mitre shells, which all have a pointed form similar to the ceremonial hats worn by bishops and popes. The papal mitre may be up to 15 cm (6 in) long.^4
CUBAN LAND SNAIL
Some land snails are brightly coloured too, but their colours are usually similar to those of the places where they live. Snails that have noticeably different colours are soon eaten by birds.
A nautilus can
adjust its buoyancy by pumping fluid in and
out of gas-filled shell chambers
This delicately ribbed
seashell was once
highly valued, which
explains its name
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44
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Cowrie shells are glossy where partly covered by the animal’s body
Distorsio shells are
found mainly in tropical waters
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