Carp

Carp is a common name for many species of freshwater fish. These fish belong to the family Cyprinidae. This is a very large group of ray-finned fish. Most of these species are native to Eurasia.

People view carp in many different ways depending on where they live. In the Old World, they are often valued as food or ornamental fish. However, in places like Australia, Africa, and much of the United States, they are seen as invasive pests. This means they can move into new areas and out-compete local species.

Many carp belong to a group called the Ostariophysi. This superorder includes the Cypriniformes family. These fish share specific anatomical features. They live mostly in fresh water. They also possess Weberian ossicles. These are special structures made from the first five vertebrae. They also include corresponding ribs and neural crests. The third pair of ribs touches the labyrinth and the swim bladder. Scientists believe these structures help transmit vibrations. This process likely helps the fish perceive sound. This explains why many of these fish have a great capacity for hearing.

Carp species vary greatly in size and behavior. The common carp, or Cyprinus carpio, can reach 110 centimeters in length. It can weigh up to 40.1 kilograms. The grass carp is even larger, reaching 150 centimeters. Other species include the silver carp and the bighead carp. Some carp are quite hardy and can survive extreme conditions. For example, some species can live for months without much oxygen. This happens under ice or in stagnant water. They do this by metabolizing glycogen into lactic acid. They then convert that acid into ethanol and carbon dioxide. The ethanol eventually diffuses into the water through their gills.

Humans have a very long history with carp. Aquaculture is the practice of farming fish. In China, people have practiced aquaculture for at least 2,400 years. A text by Fan Li from the fifth century BC describes how to raise carp in ponds. Different species were domesticated independently in different parts of Eurasia. The common carp is native to Central Europe. Other species, known as Asian carp, were domesticated in East Asia. Some species from South Asia are called Indian carp.

Selective breeding has changed how carp look. This is when humans choose specific fish to breed. In Japan, people have bred the Amur carp for ornamental purposes since the early 19th century. These are known as koi. In China, people began breeding goldfish for color over a thousand years ago. Goldfish were originally domesticated from a dark greyish-brown carp. Scientists also use selective breeding to improve food fish. In the USSR, researchers selected carp for better growth and cold tolerance. They created the Ropsha carp, which showed up to 77.4% better cold tolerance. In China, scientists developed the Jian carp. This variant grows rapidly and has a high feed conversion rate.

In the United States, the history of carp is complicated. They were introduced to the country in the 1880s. For a long time, they had a poor reputation as a "rough fish." Many people saw them as a damaging invasive species. However, many states are changing their view. Some now see them as a great target for recreational fishing. These fish are strong and fight hard on a line. Groups like the American Carp Society promote carp angling as a unique sport.

Carp are connected to many different parts of human life. They are vital to the global food system through aquaculture. In Asia, carp farming surpasses the volume of intensive sea-farmed species like salmon. They are also central to the ornamental fish industry. You can see this in beautiful koi in garden ponds or goldfish in aquariums.

Even the way people study biology is linked to them. Their unique ability to survive low oxygen provides a fascinating look at animal metabolism. Whether as a food source, a pet, or a challenge for anglers, carp remain a significant part of our world.