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
Clams reproduce by releasing gametes, or eggs and sperm, into the water. Male and female clams have no direct contact. The clams are prompted to reproduce by changes in the water's temperature and pH. In the quahog clam, spawning usually happens during neap tides, which is the lowest point of a high tide.Full Answer >
Freshwater clams filter food and nutrients out of the water. If they are in an aquarium, their diets can also include invertebrate food to supplement their natural food intake.Full Answer >
All hard clams start out their adult lives as males. In later years, the larger clams often switch from the production of sperm to the production of eggs, effectively changing their sex to female.Full Answer >
Some squid species live in shallow waters near coastlines, but others live in deeper ocean waters. The California shoreline and Florida coast are popular spots. The lifespan of species that live in deeper waters is often longer because these spots offer more plentiful food and less hunting by humans.Full Answer >