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What is an Antarctic Cod?

Angie Bates
Angie Bates

The Antarctic cod is a large fish that lives in the open ocean around Antarctica. Also called the Antarctic toothfish, this fish is not actually a species of cod, which is in the family Gadidae. Instead, it belongs to the family Notothenidae. This toothfish is often called a cod, however, because its flesh tastes similar. The scientific name for the Antarctic cod is Dissostichus mawsoni.

Normally found in the Ross Sea, the Antarctic cod often lives at depths of about 5,000 feet (1,524 m), though some have been documented as deep as 6,500 feet (1,981 m). In order to live in the extremely cold waters of its environment, this fish has glycoprotein, an antifreeze, in its blood, which allows it to swim without freezing. All members of the Notothenidae family possess glycoprotein.

The open ocean around Antarctica is home to the Antarctic cod.
The open ocean around Antarctica is home to the Antarctic cod.

The Antarctic cod is silvery-brown and can have spots. It has a large head, a narrow body and eyes adapted for low light. Unlike many fish, this toothfish does not have a swim bladder. Instead, it has fatty deposits that it uses to store energy. Its skeleton is cartilaginous and lightweight, and its white flesh has a high concentration of oil.

On average, these fish can be as big as 5.7 feet (1.7 m) and weigh about 176 pounds (80 kg). The largest recorded Antarctic cod was more than 6.5 feet (2 m) long and weighed about 300 pounds (136 kg). These fish live 20-25 years and do not reach maturity until they are about eight years old.

Antarctic cods mainly eat fish and are the primary predator of fish in their habitat. They will also eat crustaceans and squid, however. Antarctic cods are preyed on by sperm whales and some species of seals and killer whales.

An Antarctic cod's diet might occasionally include small squid.
An Antarctic cod's diet might occasionally include small squid.

These fish are commercially fished and are sometimes marketed in the United States as Chilean sea bass. As of 2010, they were in danger of being over-fished. The Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) put restrictions on fishing them. In addition, the environmental action group Greenpeace added them to its seafood red list.

Hypothermia treatment might benefit from an understanding of the slow heartbeat of the Antarctic cod.
Hypothermia treatment might benefit from an understanding of the slow heartbeat of the Antarctic cod.

In addition to being used for food, the Antarctic cod is also useful in medicine. Its heart has been studied in conjunction with cardiac medicines because of its slow beat. Beating only once every six seconds, the Antarctic cod's heart might help researchers discover better ways to deal with hypothermia and surgeries in which the heart must be slowed.

Frequently Asked Questions

What is an Antarctic cod and where can it be found?

Killer whales prey on Antarctic cod.
Killer whales prey on Antarctic cod.

An Antarctic cod, also known as the Antarctic toothfish, is a large fish species native to the cold waters surrounding Antarctica. It thrives in the Southern Ocean and can be found at depths ranging from the surface to 2,200 meters. This species is well-adapted to the frigid environment, with antifreeze proteins in its blood to prevent ice crystal formation.

How does the Antarctic cod adapt to its cold environment?

The Antarctic cod has developed several adaptations to survive in sub-zero temperatures. It possesses antifreeze glycoproteins in its blood and body fluids to prevent ice crystal formation. Additionally, it has a slow metabolism and a large liver that stores energy, allowing it to endure long periods without food in its harsh habitat.

What is the size and lifespan of an Antarctic cod?

The Antarctic cod can grow to impressive sizes, with some individuals reaching up to 2 meters in length and weighing over 100 kilograms. They have a relatively long lifespan, with some living up to 50 years. Their growth rate is slow, which is typical for species living in such cold environments.

What is the diet of an Antarctic cod?

The Antarctic cod is a predatory fish that primarily feeds on other fish, krill, and squid. Its diet is rich in protein, which is essential for maintaining its large size and muscle mass in the cold Antarctic waters. The toothfish uses its sharp teeth to capture and consume its prey efficiently.

Is the Antarctic cod an important species for the ecosystem?

Yes, the Antarctic cod plays a crucial role in the Southern Ocean ecosystem. It is a top predator and thus helps maintain the balance of marine life by controlling the populations of its prey. Its presence also provides food for other predators, such as seals and large seabirds, making it an integral part of the food web.

Are Antarctic cods threatened or endangered?

Antarctic cods, particularly the Patagonian toothfish, face threats from illegal, unreported, and unregulated fishing, which can lead to overfishing. Conservation measures, including the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), have been established to manage fishery practices and protect these species. However, their status requires ongoing monitoring to ensure sustainable populations.

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    • The open ocean around Antarctica is home to the Antarctic cod.
      By: axily
      The open ocean around Antarctica is home to the Antarctic cod.
    • An Antarctic cod's diet might occasionally include small squid.
      By: hiphoto39
      An Antarctic cod's diet might occasionally include small squid.
    • Hypothermia treatment might benefit from an understanding of the slow heartbeat of the Antarctic cod.
      By: Sergey Rusakov
      Hypothermia treatment might benefit from an understanding of the slow heartbeat of the Antarctic cod.
    • Killer whales prey on Antarctic cod.
      By: desertsolitaire
      Killer whales prey on Antarctic cod.