Atlantic Bay Scallop

argopecten irradians

The Atlantic Bay Scallop is a charismatic marine bivalve native to the shallow estuaries and bays of the western Atlantic Ocean. Renowned for its culinary value, this scallop is even more fascinating in its natural environment. Unlike many sedentary bivalves like oysters or clams, the bay scallop is a highly active swimmer. It propels itself through the water by rapidly clapping its shells together, ejecting water to escape predators like crabs and sea stars. This unique behavior makes it a dynamic resident of seagrass meadows. Beyond its mobility, the bay scallop is famous for its ring of bright blue eyes nestled along the edge of its mantle, which can detect light changes and movement, helping it stay vigilant in its vibrant marine home.

Habitat: Found in shallow, protected coastal bays and estuaries, particularly nestled within dense eelgrass beds that provide shelter and substrate for juveniles.

Appearance

This scallop features a symmetrically fan-shaped, ribbed shell with 17 to 22 radiating ridges. The shell's color varies widely, ranging from dark gray, black, or brown to beautiful shades of orange, yellow, or white, often with mottled patterns. A key identifying feature is the row of 30 to 40 bright, iridescent blue eyes lining the outer edge of its mantle inside the open shell, flanked by small, sensitive sensory tentacles. The shell typically measures between 5 and 9 centimeters in width.

KingdomAnimaliaPhylumMolluscaClassBivalviaOrderPectinidaFamilyPectinidaeGenusArgopecten

Atlantic Bay Scallop

Interesting facts

A bay scallop's swimming speed is powered by its large central adductor muscle, which is also the main part harvested for seafood lovers.

Atlantic Bay Scallops have up to 40 glowing blue eyes that utilize mirrors made of guanine crystals instead of lenses to focus light.

They are hermaphroditic, possessing both male and female reproductive organs, and can release both eggs and sperm into the water to reproduce.

Unlike oysters and mussels, bay scallops cannot close their shells tightly for long periods and will die quickly if kept out of water.

Special abilities

Rapidly claps its shells together to force water out from its mantle cavity, allowing it to swim backward in short, energetic bursts to escape predators.

Possesses up to 40 complex blue eyes equipped with double retinas and parabolic mirrors, capable of detecting subtle shadows and nearby movement.

Juveniles secrete strong, temporary silk-like threads called byssus to anchor themselves securely to blades of eelgrass, preventing them from being washed away by strong currents.

Measurements & details

Length: 5-9 cm
Weight: 0.03-0.12 kg
Lifespan: 1-2 years
Top Speed: 2 km/h

Diet & Feeding

It is a filter feeder that actively pumps seawater through its gills to trap microscopic nutrients and organisms.

Age differences: Larvae consume smaller planktonic organisms, while adults filter larger microalgae and organic particles from the water column.

Primary Foods

Phytoplankton
Microalgae
Organic detritus
Bacterioplankton

Foraging Method

Filtering

Ecological connections

host plant

Eelgrass

Zostera marina

Young bay scallops attach to eelgrass blades to stay off the muddy bottom and avoid predators.

eaten by

Blue Crab

Callinectes sapidus

Blue crabs are major predators of young and adult bay scallops, easily crushing their shells.

eaten by

Forbes' Sea Star

Asterias forbesi

Forbes' sea star preys on scallops by wrapping around them and using suction to pry open the shells.

Traits

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Also known as

No aliases listed yet.

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Safety

Danger

1/5 · Very low

No special safety notes yet.

Frequently Asked Questions

How to identify Atlantic Bay Scallop?

The easiest way to identify Atlantic Bay Scallop is to use the Snappit nature identifier app.

How long is Atlantic Bay Scallop?

5-9 cm

How much does Atlantic Bay Scallop weigh?

0.03-0.12 kg

How long does Atlantic Bay Scallop live?

1-2 years

How fast can Atlantic Bay Scallop move?

2 km/h

What does Atlantic Bay Scallop eat?

It is a filter feeder that actively pumps seawater through its gills to trap microscopic nutrients and organisms.

Where is Atlantic Bay Scallop usually found?

Found in shallow, protected coastal bays and estuaries, particularly nestled within dense eelgrass beds that provide shelter and substrate for juveniles.

How does Atlantic Bay Scallop hunt?

Filtering