Difference Between Mussels and Clams

Mussels vs Clams

Mussels and clams are amongst the most delicious seafood, yet those are a little too difficult to differentiate due to their close resemblance, being members of the same taxonomic class, bivalves. Therefore, understanding the difference may be important. Their habitats and habits with the external morphology are amongst the best characteristics, to explore differences between them.


Mussel is technically used to refer many types of bivalves living in both freshwater and saltwater ecosystems. However, most often mussels are the edible bivalves of the Family: Mytilidae. The great majority of those edible mussels live attached to the substrates in the intertidal zone. They prefer to keep attached to substrates that are mostly exposed, and their byssal threads are used for the attachment. However, some species prefer to live around deep-sea hydrothermal vents.

Mussels have a long pair of shells and the muscular foot is prominent out of all the organs. When powerful waves are thrashed against their bodies, it would be easy for them to detach and washed away, but they clump together on to substrates so that they are attached well enough. These can be referred as symbiotic colonies; individuals at the middle of the clump are saved from dehydration during the low tide by sharing the water collected by the other individuals.

Mussels have separate males and females; their fertilization takes place externally, the eggs develop into larvae, and those larvae live attached to gills or fins as temporary parasites, which are known as Glochidia. It is important to know that these glochidia have specific fish species as their hosts. After the glochidia stage (two weeks after), they start their independent lifestyle. Predators are a main threat that they have to survive, and humans are the unbearable problem for the mussels. That is because of the unmatched taste of mussels, and now the mussels have been grown to yield this delicious protein source.


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.

What is the difference between Mussels and Clams?

• Mussels have a long shell, while clams have a broad and round shell.

• Mussels have a temporary parasitic stage, called glochidia, in their life cycle but not in clams.

• Clams can keep their shell closed tighter than that of mussels.

• Mussels usually live on the exposed substrates of coasts, whereas clams prefer to live in burrows.

• Mussels can withstand the thrashing against powerful waves, but clams do not face such challenges.