Nototheniidae

Nototheniidae is a family of fish that are commonly known as Antarctic toothfish. They are a group of perciform fish that reside in the Southern Ocean surrounding Antarctica. The family includes several subfamilies and numerous species, many of which are uniquely adapted to the cold, harsh conditions of their environment.

Taxonomy

The family Nototheniidae is part of the order Perciformes, a diverse group of ray-finned fish. Within the family, there are several subfamilies, including Artedidraconinae, Bathydraconinae, Channichthyinae, and Nototheniinae. Each of these subfamilies contains multiple species, with the Nototheniinae subfamily being the most diverse.

Distribution and Habitat

Nototheniidae are endemic to the Southern Ocean, the body of water surrounding the continent of Antarctica. They inhabit a range of depths, from shallow coastal waters to the deep sea. The extreme cold of this environment has led to the evolution of several unique adaptations among Nototheniidae species.

Adaptations

One of the most notable adaptations of Nototheniidae is the presence of antifreeze glycoproteins in their blood. These proteins prevent the fish's blood from freezing in the extremely cold waters of the Southern Ocean. Some species also have a reduced hemoglobin content in their blood, which is thought to be an adaptation to the high oxygen content of cold water.

Conservation

While some species of Nototheniidae are commercially fished, others are considered threatened due to overfishing and the impacts of climate change on their cold-water habitat. Conservation efforts for these species are ongoing.

See Also

• Antarctic toothfish
• Antifreeze protein
• Perciformes