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Open oyster on a market in Lyon
pearl oyster
The oyster is a sessile (immobile) mollusc that is commonly found clinging onto shipwrecks, debris and harbour walls around the world. Oysters are bivalve molluscs meaning that they are closely related to other animals such as scallops, clams and mussels.

Oysters are found in salt water environments all around the world but are more commonly found in more temperate regions where the shallows are richer in nutrients. Oysters are thought to be among the oldest animals on the planet although their exact evolutionary path remains unclear.

As with other molluscs, oysters filter water in and out of their protective shells so that their vulnerable bodies inside are never put in danger. The hard shell of the oyster is primarily made up from calcium.

Despite there being numerous different species of oyster, oysters are generally split up into four distinct groups, which are true oysters (the ones eaten by humans), pearl oysters (produce pearls), thorny oysters (also known as spiny oysters) and saddle oysters (have very thin shells).

Oysters are filter-feeders so collect their nutrients by taking in water and their gills filter and collect food that the stomach then digests, dispersing the remaining water out of it's shell. Oysters are thought to be able to process up to 10 litres of water an hour so can vary in quality depending on the quality of the water.

Due to their small size and the fact that they don't move once they are adults, oysters are preyed upon by numerous different predators both in the sea and on the land. Humans, birds, marine mammals, sea turtles and various species of fish all prey upon the oyster.

Oysters have varying methods of reproduction. as some oyster species are hermaphrodites and some have separate sexes. Female oysters release millions of eggs into the water, where fertilization occurs externally. The oyster larvae develop within a matter of hours, and spend their first few weeks swimming around until they finally settle and attach themselves to objects, where they remain for the rest of their lives.

Today, although now commercially farmed, wild oysters are becoming rarer mainly due to increasing levels of pollution. Although many oysters have adapted to life in poor quality water, they are not as healthy as those oysters that are filtering water that is chemical-free.

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"awsome article"

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Oyster Facts

Five groups that classify all living things...
A group of animals within the animal kingdom...
A group of animals within a pylum...
A group of animals within a class...
A group of animals within an order...
Common Name:
Most widely used name for the species...
Scientific Name:
Comprised of the genus followed by the species...
What kind of foods the animal eats...
Size (L):
How long (L) or tall (H) the animal is...
3cm - 15cm (1.2in - 6in)
The measurement of how heavy the animal is...
50g - 200g (1.7oz - 7oz)
Number of Species:
The total number of recorded species...
Average Lifespan:1 - 3 years
Conservation Status:
The likelihood of the animal becoming extinct...
Least Concern
The colour of the animal's coat or markings...
Black. Brown, Yellow, Tan, Silver, White
Skin Type:
The protective layer of the animal...
Favourite Food:Plankton
The specific area where the animal lives...
Reefs and rocky shores
Average Litter Size:
The average number of babies born at once...
Main Prey:
The food that the animal gains energy from...
Plankton and Nutrients in Water
Other animals that hunt and eat the animal...
Fish, Birds, Humans
Distinctive Features:
Characteristics unique to the animal...
Filter water through their hard shell

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