Of the 15,000 species of bivalves known as clams, some have life cycles of only one year. Individuals of one species called the ocean quahog, or Arctica islandica, however, are among the oldest living animals on Earth, with one captured specimen measured to be more than 500 years of age.Know More
Researchers usually measure the age of clams by the growth rings on their hinge ligaments or the outside of the shell. An ocean quahog clam found off the coast of Iceland in 2006 was first determined to be 405 years old. However, a later, more comprehensive analysis confirmed that the clam was actually 507 years old. Because the clam had to be opened to determine its age, it died, or it might have lived even longer. The clam was nicknamed Ming because it was conceived during the Chinese Ming Dynasty. Ming's status as the world's oldest animal was confirmed using the carbon-14 dating method.
Clams have two equal shells that are held together with a ligament and opened and closed with muscles. They have strong, burrowing feet that they use to bury themselves in sand. They are filter feeders that use siphons to draw water into themselves for feeding and breathing. They vary in size from nearly microscopic species to giant clams that can weigh more than 440 pounds. Many clam species inhabit shallow fresh and salt waters, but one species of clam in the Pacific Ocean has been found at a depth of 16,000 feet.Learn more about Marine Life
The differences between clams, mussels and oysters lie mostly in the shapes of their shells. Many types of clams have the classic clam-shaped shell with ridges or concentric rings. They also come in many colors and sizes, though the ones sold at the fishmonger's are only a few inches long. Razor clams resemble straight razors.Full Answer >
There are many different oceanic mollusks, such as clams, octopus and oysters, but there are also mollusks that live on land, such as snails and slugs. Mollusks are the second largest group of invertebrates in the world, with somewhere between 50,000 and 200,000 living species.Full Answer >
Sharks are found in every ocean in the world and are sometimes found out of their habitat in rivers and streams. There are around 368 species of sharks in the world.Full Answer >
Giant stingrays eat mainly clams and crabs. Stingrays often bury themselves in the mud on the bottom of a river to await prey. They have a sensor that allows them to detect the electrical field of approaching animals.Full Answer >