Last updated: May 27, 2024
Verified by: AZ Animals Staff
© aquapix/Shutterstock.com

They have eyes all over their bodies


Oyster Scientific Classification

Scientific Name

Read our Complete Guide to Classification of Animals.

Oyster Conservation Status

Oyster Locations

Oyster Locations

Oyster Facts

Algae and other food particles
Group Behavior
  • Colony
Fun Fact
They have eyes all over their bodies
Estimated Population Size
Biggest Threat
Crabs, seabirds, humans, starfishes
Most Distinctive Feature
Gestation Period
7-10 days
Reefs and rocky shores
Crabs, seabirds, humans, starfishes
Average Litter Size
Favorite Food
Algae and other food particles
Marine creatures
Common Name
Number Of Species
Can process up to 10 litres of water an hour!

Oyster Physical Characteristics

  • Grey
  • White
  • Silver
Skin Type
20 years in captivity
50 grams (medium-sized oyster)
62 to 64 mm

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Oysters make up a family of a large number of salt-water bivalve mollusks.

Oysters are marine animals that are often found in brackish habitats. They are very irregular in shape and the valves of some are highly calcified. They belong to the phylum Mollusca.

Oysters are animals that eat algae and other food particles that are usually drawn to their gills. They are known to reproduce through broadcast spawning in warm waters and are also capable of changing their gender. Every oyster is capable of making at least one pearl in its lifespan.

Incredible Oyster facts!

Animals With Exoskeletons-oyster

Humans have been eating and cultivating oysters for thousands of years.


  • Can filter water: These marine animals can filter up to 1.3 gallons of water per hour.
  • Ancient beings: Oysters have been used and fed on by humans for thousands of years.
  • Too many eyes: Oysters are animals with eyes all over their body. These eyes help them escape their predators.
  • Shell-hiding: These creatures are known to hide in their shell upon sensing danger. The shells then close tightly to protect them.
  • No central nervous system: These animals do not have a central nervous system. Therefore, they cannot feel pain like humans.

You can check out more incredible facts about oysters.

Evolution and Origins

According to zoologists, the initial oyster species emerged during the Triassic era, more than 200 million years ago, when dinosaurs were prevalent on Earth. Based on fossil evidence, oysters have been traced back to around 145 million years ago. Hence, it can be inferred that oysters have existed since the beginning of human civilization.

Researchers have potentially discovered the individuals who were the first to consume shellfish. While excavating a cave in South Africa, scientists found indications of shellfish meals that date back to 164,000 years ago.

Furthermore, to be able to reproduce, oysters generate larvae, which float for a period of two to three weeks. During this time, a large number of them are consumed by minor predators or perish due to other reasons, while the surviving ones settle on a surface.

Preferably, they anchor themselves onto an established oyster reef where they remain for the rest of their lives. Upon attachment to any surface, the larvae are referred to as “spat”.

Different Types

  • Ostrea edulis
  • Chilean oyster
  • Akoya pearl oyster
  • Eastern oyster
  • Windowpane oyster
  • Pinctada maxima
  • Pinctada margaritifera
  • Saccostrea glomerata
  • Ostrea lurida
  • Spondylus gaederopus
  • Ostrea denselamellosa
  • Ostrea angasi
  • Suminoe oyster
  • Portuguese oyster
  • Ostrea conchaphila
  • Pinctada albina
  • Saccostrea echinata
  • Dendostrea sandvichensis
  • Crassostrea gryphoides
  • Pinctada nigra
  • Saccostrea kegaki
  • Dendostrea folium
  • Spondylus squamosus
  • Enigmonia Monia zelandica
  • Anomia trigonopsis
  • Crassostrea echinata
  • Dimya maoria

Classification and Scientific Name


©Anthere / Creative Commons – Original

These animals go by the scientific name Ostreidae and belong to the class Bivalvia and subclass Pteriomorphia. They belong to the kingdom Animalia and Phylum Mollusca.

The scientific name Ostreidae is a combination of two words – Ostrea and the suffix -idae. The suffix is fairly common in ocean life, coming from the ancient Greek word eîdos for “appearance” or “resemblance.” In this case, the suffix refers to the Latin word for oyster (“Ostrea”).

Ostrea goes further back to predate ancient Greek language from the word “ὀστέον,” which means “bone.” The name is likely a reference to the uniquely shaped shell.


There are about 200 species of oysters around the globe. The oysters make a large family of a bivalve mollusks. In the United States, there are only five species that are typically sold to consumers as food. Those species include Pacific -, Atlantic -, Kumamoto -, Olympia oysters, and European flats.

Many species can change their gender at some point. While some may only switch genders once or twice, this process can be repeated multiple times.


Many oysters are irregular in shape with oval and/or pear-shaped shells. The shells are usually whitish-grey and the inside of the shell is usually white.

These animals are known to have very strong adductor muscles that help them in shutting their shells when they hide inside them upon sensing danger. They are usually 62 to 64 mm long and a medium oyster usually weighs about 50 grams.

Open oyster on a market in Lyon

Open oyster on a market in Lyon

©Chris 73 / Wikimedia Commons / Creative Commons – Original

Distribution, Population, and Habitat

These marine creatures are usually found in the brackish and salty waters across the US coasts. They usually exist in clusters and are often found on shells, rocks, or any other hard surface.

The clusters often fuse together and eventually form rock reefs that eventually also become a habitat for many other marine animals.
The total number of their populations around the globe is not known. However, the bivalve mollusk exists in large numbers in water bodies around the world and these marine creatures are not yet threatened or endangered.

Predators and Prey

oyster vs mussel

They may not have a brain, but an oyster’s ability to make pearls is notable.

©Pix Box/Shutterstock.com

Like almost all other living animals, they are also an integral part of the environmental food chain and are eaten by other creatures. The main predators of oysters include crabs, starfish, humans, and seabirds, due to the amount of protein and other nutrients that they offer.

Not all predators go after these creatures for their meat. The boring sponge, for example, will infiltrate the shell to kill the animal and take it over for its own home. The oyster flatworm (a.k.a. the oyster leech) will go after young oysters when they eat, sneaking into the shell. After the flatworms have eaten the meat, they use the shell to protect their eggs.

Meanwhile, these marine creatures are not known to feed on other animals and are known to usually eat algae and other food particles as water rushes over them.

Reproduction and Lifespan

These animals are known to reproduce using broadcast spawning which means that the female and male release the eggs and sperm into warm waters, which is where they hatch. The gestation period lasts about 7 to 10 days before the live oyster is released.

While in captivity, the typical lifespan for these animals is 20 years, but proper care is needed. They are not currently considered to be endangered, but much of the impact on their lifespan in the wild has to do with the fishing of these animals.

Fishing and Cooking

Oysters can very well be caught and cooked. In fact, they are widely eaten across the world. However, if not cooked properly, they could make you ill. Cooking them well kills unnecessary bacteria and also eliminates the risk of infection. If prepared properly, these animals offer an excellent source of protein and vitamins.

Differentiating between the species is crucial since they all have different flavors and ways to prepare them. For example, Eastern oysters in the United States are much saltier than Pacific oysters, but the latter has a more savory taste for a complex palate.

Oysters are an incredibly flexible dish since they can be steamed, pan-seared, poached, smoked, fried, or prepared in nearly any way. They can even be baked. Most interestingly, their flavor can make them an excellent aphrodisiac for a romantic dinner for two.

Some vegans will opt to eat oysters as well. Though it is a living things, oysters lack a central nervous system. Without these nerve endings, they cannot experience pain and they do not move.

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About the Author

Rebecca is an experienced Professional Freelancer with nearly a decade of expertise in writing SEO Content, Digital Illustrations, and Graphic Design. When not engrossed in her creative endeavors, Rebecca dedicates her time to cycling and filming her nature adventures. When not focused on her passion for creating and crafting optimized materials, she harbors a deep fascination and love for cats, jumping spiders, and pet rats.

Oyster FAQs (Frequently Asked Questions) 

Where are oysters found?

Oysters can mostly be found in the salty and brackish waters along the US coasts.

Do oysters have eyes?

Yes, these marine creatures have eyes all over their bodies that allow them to escape their predators.

Can you eat oysters?

Yes, you can eat oysters. However, if not cooked properly, they can make you ill.

Who eats oysters?

Seabirds, starfishes, humans, and crabs are the major predators of the oysters.

What do oysters eat?

Oysters feed on algae and other food particles that are drawn to their gills.

Can every oyster produce a pearl?

Yes, every oyster is capable of producing at least one pearl.

What Kingdom do Oysters belong to?

Oysters belong to the Kingdom Animalia.

What class do Oysters belong to?

Oysters belong to the class Bivalvia.

What phylum to Oysters belong to?

Oysters belong to the phylum Mollusca.

What family do Oysters belong to?

Oysters belong to the family Ostreidae.

What order do Oysters belong to?

Oysters belong to the order Ostreoida.

What type of covering do Oysters have?

Oysters are covered in Shells.

How many babies do Oysters have?

The average number of babies an Oyster has is 1,000,000.

What is an interesting fact about Oysters?

Oysters can process up to 10 liters of water an hour!

What is the scientific name for the Oyster?

The scientific name for the Oyster is Ostreidae.

What is a distinguishing feature of the Oyster?

Oysters have shells.

How many species of Oyster are there?

There are 200 species of Oyster.

What is the biggest threat to the Oyster?

The biggest threats to the Oyster are crabs, seabirds, humans, and starfish.

How many Oysters are left in the world?

The population size of the Oyster is unknown.

How do Oysters have babies?

Oysters lay eggs.

What's the difference between an oyster and a mussel?

There are many differences between an oyster and a mussel, including their size. Oysters are larger than mussels and have a much thicker shell. Mussels are also found in both saltwater and freshwater, while oysters only live in saltwater.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.


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  2. Tom Jackson, Lorenz Books (2007) The World Encyclopedia Of Animals / Accessed May 17, 2010
  3. David Burnie, Kingfisher (2011) The Kingfisher Animal Encyclopedia / Accessed May 17, 2010
  4. Richard Mackay, University of California Press (2009) The Atlas Of Endangered Species / Accessed May 17, 2010
  5. David Burnie, Dorling Kindersley (2008) Illustrated Encyclopedia Of Animals / Accessed May 17, 2010
  6. Dorling Kindersley (2006) Dorling Kindersley Encyclopedia Of Animals / Accessed May 17, 2010
  7. National Geographic / Accessed November 27, 2020
  8. Wikipedia / Accessed November 27, 2020
  9. Oyster House / Accessed November 27, 2020
  10. Food & Wine / Accessed November 27, 2020
  11. NOAA Fisheries / Accessed November 27, 2020
  12. HuffPost / Accessed November 27, 2020

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