Molluscs: Clams, Mussels, Oysters, Scallops, Squid, and Relatives
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watched carefully and removed from salt water as soon as they shed their old shell, since their new cuticle would otherwise become leathery within hours and calcified hard in two or three days Molluscs: Clams, Mussels, Oysters, Scallops, Squid, and Relatives Molluscs are the strangest creatures we eat Take a close look sometime at an intact abalone or oyster or squid! But strange or not, molluscs are plentiful and delicious Judging by the massive prehistoric piles of oyster, clam, and mussel shells that dot the planet’s seacoasts, humans have feasted on these conveniently sluggish creatures from the earliest days This highly successful and diverse branch of the animal kingdom got its start half a billion years ago and currently includes 100,000 species, double the number of fish and animal species with backbones, from snails just a millimeter across to giant clams and squids The secret to the molluscs’ success — and their strangeness — is their adaptable body plan It includes three major parts: a muscular “foot” for moving; an intricate assembly that includes the circulatory, digestive, and sexual organs; and enveloping this assembly, a versatile sheet-like “mantle” that takes on such jobs as secreting materials for a shell, supporting eyes and small tentacles that detect food or danger, and contracting and relaxing to control water flow into the interior The molluscan shellfish that we eat have combined these parts in very different ways Abalones, the most primitive, have one cup-like shell for protection, and a massive, tough muscular foot for moving along and clinging to the seaweed on which their rasping mouths feed Clams are enclosed in two shells, and ... supporting eyes and small tentacles that detect food or danger, and contracting and relaxing to control water flow into the interior The molluscan shellfish that we eat have combined these parts in very different ways Abalones, the most primitive, have one.. .of fish and animal species with backbones, from snails just a millimeter across to giant clams and squids The secret to the molluscs’ success — and their strangeness — is their adaptable body... Abalones, the most primitive, have one cup-like shell for protection, and a massive, tough muscular foot for moving along and clinging to the seaweed on which their rasping mouths feed Clams are enclosed in two shells, and