One of most people’s fondest childhood memories is going to the beach, strolling along the shore and picking up seashells. And, I believe none of us thought that they are different from each other. They might come in different shapes, colors and sizes, but if you are a six-year old, they are all the same creatures with hard and colorful shells.
This article aims to further explain the world of clams. From the small creatures on the shore, we will look at them in a more precise perspective.
What are Clams? Some Basic Info
Clams are edible infaunal bivalve mollusks. They spend most of their life buried in the sand of the ocean floor. They come in different colors and shapes, but they have something in common in terms of their physical appearance. All clams have two bilaterally symmetrical shells that are joined together and opened by an internal or external ligament and two adductor muscles.
You’ve heard that right. They have structures that are similar to that of human’s anatomy. You see, humans also have ligaments that attaches muscle to another muscle and we also have adductor muscles that are located on our arms and thighs. Come to think of it, we are from a remotely related kingdom, however, we somewhat share a similar feature with them. Isn’t that spectacular?
How do Clams Breathe?
If you want to study on an underwater animal, this is one of the most basic things that you should be familiar with. How do they breathe in spite of being submerged in the deep seas and rivers? This is indeed new for us, who spend most of our lives in land, but this capacity of taking in Oxygen in the waters has already been with them since day one.
Marine animals breath in the oxygenated water through their mouths. They gulp a large amount of it, then acquire the dissolved oxygen in it through their gills. The water has higher concentrations of dissolved oxygen compared to their blood, so it is absorbed in their body. The deoxygenated water from the water they took in and from their blood will then be pushed out through their gills.
Interestingly, clams also have gills. Their respiration process is similar with that of fishes, so when you see bubbles floating around them, it is probably because they are breathing. However, they also have siphons or necks, a tube-like structure, which they extend when they respire.
What are the Different Types of Clams?
Hard Shell Clams or Round Clams (Mercenaria mercenaria)
Chowder, top neck, middle neck and cherry stone clams are classified as hard shell clams. They are often found in the oceans, especially on Atlantic Ocean, along the coasts of US and Canada. They are often cooked or served in raw.
Soft-Shell Clams or Steamers (Mya arenarya)
These clams are lighter in color than hard-shell clams, with more brittle and elongated shells. These clams are often found on the east shores of Canada, US and UK. They are also edible, and is often served with chowders.
Manila Clams or Steamers (Venerupis philippinarum)
Manila clams are much more similar to hard shell clams, only that they are more oval in shape and their shells are sculptured with radiating ribs. They are often commercially harvested, however, they originated in the shores of Pacific Ocean.
Razor Clams or Pacific Clams (Siliqua patula)
These clams have long and thin shells which often bury themselves in the sand vertically. They are also cooked and served in restaurants, however they should be thoroughly cleaned since they are sandy and gritty due to their position in the sand.
Ocean Quahogs (Arctica islandica)
These clams are darker in color compared to the hard-shells, although they resemble hard-shell clams closely. They are called ocean quahogs because their natural habitats is in the depths of the oceans.
Surf Clams or Bar Clams (Spisula solida)
These clams are called surf clams since the waves bring them to the shore. They are often found in the Pacific and they are also a good clam to use for chowder.
Donax Clams or Coquinas (Donax Trunculus)
Originated in Europe, these clams are also edible and are often included in pasta. Their distinct triangular shape makes them unique if compared to other seashells.
What Do Clams Eat?
We’ve mentioned earlier that clams use their siphons in taking in water. Now this anatomical structure is also used by mollusks to take in their food. They tend to acquire their food by extending their siphons during high tide, the time when ocean clams eat. Freshwater clams, however, take in their food whenever they want, since they have enough supply of water.
By nature, clams are filter-feeders. They feed on suspended particles that are floating on the water. These particles may include planktons, algaes, and other microorganisms present in water. It is safe to say that clams are indiscriminate feeders. They are never picky with what they eat.
When you think of keeping them as a pet, it is important to know that although they are indiscriminate feeders, they do not readily adapt to changes in their environment. Salt water clams, for example, should not be fed when they are commercially cultivated, and more so the freshwater clams when they are kept in private fish tanks. This is due to the change of composition and microorganisms that are present in the water that they might ingest.
The Danger of Clams
Clams are not only eye-candy but they are tasty and delectable, too. Who would ever not know about clam chowder, buttered clams and clam soup? However, no matter how good they taste, they could be dangerous too, since their diet makes them susceptible to contaminants.
The Red Tide, for example, has created a loud noise in the news world wide. These are rampant when their habitat becomes polluted with oil or hazardous chemicals which they eventually ingest. Many people have been harmed because of this, and some even died when they ate the clams that were contaminated with these pollutants.
At this point, you are now well-acquainted with these creatures. You can now have fun collecting them from sea shores, making them your pets, or even putting them in your dinner plate.