Getting to know three … Bivalve edition

Ever know instinctively that some animals are ‘related’ and just can’t pinpoint their similarities? On the third day of every month I explain three features that are common among three animals of a certain group. Of course, generally each group has more than three representatives and even  many more similarities and then even more differences, but I am going to choose three similarities that link threes to keep it simplified. This month is focused the mussel, scallop, and clam. These three animals are all part of the bivalve group which is the second largest group of mollusks. The largest group of mollusks are the gastropods. Mollusks are well-known for their soft, unsegmented bodies and shell covering (although cephalopods do not have this feature). Check out the image below to learn what the featured animals all have in common.




How does an oyster make a pearl?

Chargrilled oysters

Image via Wikipedia

Oysters are another bivalve animal. In the case of all bivalves, the part of the animal that lines the shell is known as the nacre and the part of the animal that make up the outer shell is known as the mantle. A pearl is created rather by accident when something foreign gets stuck inside the mantle, thus the nacre builds up to protect the animal. This build up is known as the pearl.

Oysters, mussels, and clams all make pearls. However, they are most often seen in oysters. My theory is that the oyster shells are typically not as uniform in shape as clams and mussels and tend to grow according to their surroundings, making it easier for foreign junk to accumulate.