Clams vs Oysters
Despite the taxonomic classification and other characteristics resemblance, there are many distinctions between clams and oysters. Morphological, behavioural, anatomical, and physiological characteristics are important to consider in exploring the difference between clams and oysters.
Clams
Clams are usually the edible bivalve molluscs living in burrows. However, some countries use this as a term to refer to other bivalves depending on the local referring. Amongst the most considerable discrepancies, the United States and the United Kingdom could be considered, because the term clam is used to refer the entire taxonomic class of Bivalvia or some other types of bivalves.
Clams have two equally sized shells that are broad and wide with a more or less round shape. They can close their shells when they are threatened or alarmed. They can close their shell so tight that even had some influence to the English language with some phrases such as “happy as a clam” or “clam up”. Usually clams do not have heads, and they are blind without eyes, but Scallops have eyes.
Clams have been useful as seafood with an incomparable taste. Different cultures of the world (Asian, American, and European) have developed numerous types of foods with clams. In addition to their usefulness as food, clams have been used in the garments industry (buttons in clothes), aquaria, and even as money in some countries.
Oysters
Oyster is a common name that is used to refer few groups of marine and brackish water bivalves (Phylum: Mollusca). When it comes to oysters, their uses for the humans are very significant. In fact, they elevate the values of some human requirements, especially through providing ornaments and jewelleries. After a couple of weeks from the hatching out of the egg, they live temporarily attached to a host (Glochidia stage). After that, each individual finds a safe home and live there for the rest of the life. When there is a place where hundreds or thousands of oysters have made it their home, it is called an Oyster Bed or Oyster Reef. Oyster beds provide a great habitat for many types of animals and plants to create stabilized ecosystems. Hard shells of oysters provide substrates for a number of sea grass as well as for hundreds of small marine animals such as sea anemone, mussels, barnacles, and many more.
Oysters being filter feeders, many pollutants in marine water are removed including nitrogen-compounds, suspended particles, and phytoplankton. They are very efficient in filtering the water with an average rate of five litres per hour by only one individual. On the other hand, oysters could be considered as a self-growing “water filters” in the sea, as they are capable of producing both eggs and sperms inside the same individual. In fact, they are quite rapid in multiplying; millions of self-fertilized eggs develop into larvae in about six hours, find the permanent substrate within a couple of weeks, and mature in about a year.
Oysters are well known for their precious pearls, and pearl oysters have been cultured nowadays.
What is the difference between Clams and Oysters?
• Clams live inside crevices and burrows whereas oysters prefer to live on exposed substrates.
• Clams can move around their habitat using their foot, but oysters are attached to a particular place forever.
• Clam shell is broad and round while oyster shell is usually long and rough.
• Both are edible bivalves, but clams are more popular than oysters as food.
• Male and females are separated in clams but not in oysters.
• Oysters are more valuable than clams for the economy.
• Oysters can produce pearls but not clams.
• Clams are found in both freshwater and saltwater, but oysters are largely marine.