Pecten maximus

The great scallop lives in the sea.

It has a hard shell. The shell can be pink or red. It can also have spots. This animal has many tiny eyes. It uses a strong muscle to snap its shell. This helps it swim to escape. It also eats tiny bits of food from the water. The shell shows how old it is. It grows new lines every year.

The great scallop is a saltwater clam. It lives in the Atlantic Ocean.

Its shell has two parts. One part is flat. The other part is curved. The shell can be many colors. It may have pink, red, or yellow spots. The shell also has ribs. These ribs show how the scallop grows.

Scallops have many tiny eyes. These eyes sit on long tentacles. They use a very large muscle to move. This muscle opens and closes the shell. By snapping the shell, the scallop can swim. This helps it escape from predators like starfish.

To eat, the scallop uses tiny hairs. These hairs help it pull food from the water. This way of eating is called filter feeding. The scallop also makes a small hole in the sand. It does this by shooting water out of its shell. This lets it hide under the mud. Most scallops live for over 20 years. They can grow to be 21 cm long.

The great scallop is a fascinating saltwater clam found in the Atlantic Ocean.

People call it many names, like the king scallop or the St James shell. It is a marine bivalve, which means it has a shell made of two parts. The top shell is flat, while the bottom shell is curved. These shells can be very colorful with pink, red, or yellow spots. Large scallops can grow to be 21 cm long. They often live in offshore waters deep below the surface.

To stay safe, the scallop has a clever way of hiding. It uses its shell to shoot water into the sand. This creates a small hollow for the scallop to lie in. Once it settles, sand or mud covers the top shell. Only the tentacles and eyes stay visible to the world. The scallop is also a filter feeder. It uses tiny hairs called cilia to pull food from the water. These hairs move food along the gills to the mouth.

Scallops are not slow creatures when they are in danger. They have a very large and powerful adductor muscle. This muscle is used to open and close the shell. If a predator like a starfish approaches, the scallop can swim. It does this by clapping its valves together very fast. This action pushes jets of water out of the sides. This sudden movement helps the scallop jump forward to escape.

These animals have lived in the Atlantic for a long time. They can be found from Norway all the way down to the Iberian Peninsula. In the United Kingdom and Ireland, they live all around the coast. Some scallops can live for more than 20 years. They reach maturity when they are about 2 or 3 years old. Scientists have even studied their DNA to understand them better.

A draft genome was presented by Kenny et al. in 2020.

Humans have a long history with the great scallop. Many people enjoy eating them as a food source. In 1999, the United Nations reported a catch of 35,411 tonnes. The United Kingdom and France were the biggest catchers that year. The scallop shell is also very famous in our culture. The Shell plc company uses a scallop in its logo. Even pilgrims used these shells to honor Saint James.

The great scallop, known scientifically as Pecten maximus, is a marine bivalve mollusc. This means it is a saltwater clam with a shell made of two parts. It belongs to the Pectinidae family and is the type species for its genus. These animals are found throughout the northeast Atlantic Ocean. They are highly valued as an edible species in many parts of the world.

The anatomy of the shell is very distinctive. The right valve, or lower shell, is convex and slightly overlaps the flat left valve. Large specimens can reach a length of 21 cm. The shells feature 12 to 17 wide radiating ribs. These ribs create a crenulated or scalloped edge. Numerous concentric lines also appear on the valves. These lines serve as a growth history for the animal. The shells can show many colors. The left valve is often reddish-brown. The right valve may be white, cream, or pale brown. It can also show pink, red, or bright yellow tints. Some shells even display zigzag patterns or spots.

Inside the shell, the scallop has specialized organs for survival. A very large and powerful adductor muscle allows the animal to open and close its valves. The mantle, which is the soft body tissue, has a unique edge. The outer layer of the mantle features long tentacles. At the base of these tentacles are 30 to 36 simple eyes, also called ocelli. These eyes can be dark blue or green. The scallop also has a finger-like foot. This organ spins byssal threads. These threads are used to attach the animal to the seafloor through a small opening called the byssal notch.

Scallops use several clever mechanisms to live on the ocean floor. They are filter feeders that extract particles from the water. Small hairs called cilia create a feeding current. This current draws water across the gills. The gills trap food particles in a stream of mucous. This mucous then carries the food to the mouth. To hide, the scallop creates a small hollow in the sediment. It does this by opening and closing its valves to eject water from the mantle cavity. This raises the shell at an angle. Water then jets into the sediment to create a recess. Once settled, sand or mud covers the upper valve. Only the tentacles and eyes remain visible to the world.

While they often stay still, scallops can swim to escape predators. Starfish like Asterias rubens and Astropecten irregularis are main predators. When a threat is detected, the scallop performs an escape reaction. It rapidly claps its valves together. This action expels jets of water from each side of the hinge. The scallop jumps forward using the curved edge of the shell. This swimming is usually limited to these sudden bursts of movement. The ability to grow depends on the environment. Scallops in sheltered habitats grow faster than those in high wave action. High waves can make it hard for the feeding apparatus to work. Strong currents can also disturb the delicate process of larval settlement.

The reproductive biology of Pecten maximus is quite complex. They are hermaphroditic, meaning they have both male and female reproductive organs. These are called gonads and are shaped like tongues. The female gonads are red or orange, while the male gonads are white. Spawning is often influenced by temperature and age. Mature scallops generally spawn from April or September. A three-year-old scallop can release 15 to 21 million oocytes per emission. Fertilization happens externally in the water column. The larvae can drift for up to a month. This long larval stage helps the species distribute itself across wide areas.

Humans have a significant relationship with this species through fisheries and aquaculture. In 1999, the United Nations reported a total catch of 35,411 tonnes. The United Kingdom and France were the largest producers that year. In the UK, scallop fishing is one of the top five fisheries by value. Some scallops are caught using Newhaven scallop dredges. Others are gathered by hand by divers. Aquaculture, or farming, is also practiced in countries like Norway and France. However, scientists monitor scallops closely for domoic acid. This is a toxin that can cause Amnesic Shellfish Poisoning in humans.