Mussels vs Oysters
Similarities in the taxonomic classification and external appearances would lead someone to understand that both mussels and oysters are the same type of animals with no difference, yet many distinctions could be understood between them. Morphology, ethology, anatomy, and physiology would be helpful to consider in finding the difference between mussels and oysters.
Mussels
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.
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 Mussels and Oysters?
• Both live in large colonies, but oysters do not usually clump themselves as oysters do.
• Both oysters and mussels have long shells, but the edge and surface are rough in oysters unlike in mussels.
• Taxonomic diversity is higher among mussels than in oysters.
• Both are edible bivalves, but mussels are more popular than oysters as food.
• Male and females are separated in mussels but not in oysters.
• Oysters pose more value than mussels for the economy.
• Oysters can produce pearls but mussels cannot.