Carp

The carp is an oily ray-finned freshwater fish that has played a role in human culture for thousands of years.

As one of the most popular types of pond or aquarium fish in the world, many species of carp have undergone selective breeding for shape, color, and resistance to disease. This practice probably originated somewhere in China and then spread out to the rest of the world. Today carp fish are common in artificial ponds, aquaculture, and recreational and commercial fishing.

4 Incredible Carp Facts!

• To survive the winter season, the carp fish enters a period of lethargy in which it moves to the bottom of the water and then stops eating. This dramatically slows its metabolism until the temperature improves.
• The carp is considered to be one of the worst invading species of freshwater fish outside of its native habitat.
• Some species can survive a very long time on low oxygen content.
• Despite the reputation, the goldfish and other carp do not have a poor memory. One study suggested that goldfish can perhaps recognize human faces.

Classification and Scientific Name

There is a lot of confusion surrounding the name “carp,” because it’s an informal term and not a scientific one. The closest thing to a scientific classification is the family of Cyprinidae (which derives from the Ancient Greek name for the carp, kuprinos; this may have some connection to Aphrodite, the goddess of procreation and love). Think of it this way. Every single species of carp belong to a single family. However, not every member of the family is a carp. It also includes the minnows and the barbells.

Species

Because “carp” isn’t a well-defined scientific term, there is no single agreed-upon number of species. But there are several well-known and popular types:

• Goldfish: Descending from wild carp in China, the goldfish is a member of the crucian carp genus, but due to artificial selection, it has been altered and bred for a more pleasing appearance to the human eye. This species first came to Europe at some point in the 17th century and quickly became a favorite.
• Common Carp: Originating from the waterways of Europe and Asia, this species has brown, green, black, and white colorations. It was later introduced to the United States in the 19th century.
• Koi: With its unique patterns of bright orange or black markings all over the white body, the koi became incredibly popular in Japanese ponds and water gardens and then spread out to the rest of the world from there. It is a variation of the Amur carp.
• Grass Carp: Originating in East Asia, the grass carp is an herbivorous species with a long, almost torpedo-shaped body. Consuming up to three times its body weight in food every day, the grass carp grows very rapidly.

Appearance

This is a very diverse group of fish, but there are a few characteristics that unite them. Most of these fish have big, round bodies. They have a unique structure that connects the swim bladder with the auditory system to enhance and amplify vibrations and sounds. Most carp fish have barbels (long whiskers) for sensing the surrounding environment, but a few species lack them entirely.

In the wild, carp fish tend to have duller colors such as brown, green, silver, black, and white. But occasionally, a brighter orange or red carp will arise. These specimens have been selected by humans for their appearance to create domesticated species like goldfish. The average fish grows to 14 inches in length, but the largest specimens measure some 39 inches and 49 pounds. Crucian carp are the smallest type and usually weigh no more than 4 pounds.

Distribution, Population, and Habitat

The carp is a freshwater fish that first evolved in the lakes, rivers, and ponds of Europe and Asia, though some species may venture out into salt or brackish water for parts of the year. It was gradually introduced to other continents as a means of controlling annoying pests and plants. But due to its habit of disturbing local habitats and out-competing native fish, these fish quickly became an annoying pest itself. As concern grew that the fish would gradually take over and transform waterways, the United States began to construct a series of electric fish barriers to prevent the carp from entering the Great Lakes and disturbing the ecosystem there.

Because these fish is so well-represented throughout the world, many species are classified as least concern. However, the common carp and white carp are both considered to be vulnerable to extinction.

Predators and Prey

These fish are important intermediate fish in the freshwater ecosystem by transferring nutrients from the lower to upper parts of the food chain.

What do carp eat?

This is an omnivorous fish that digs around in the dirt at the bottom of the water for aquatic plants, insects, crustaceans, worms, and zooplankton.

What eats carp?

Adults are usually preyed on by bigger fish such as pikes and bass, plus herons, cormorants, ospreys, otters, and mink. The vast majority don’t survive until adulthood. Some egg caches are a veritable feast for a cornucopia of different predators.

Reproduction and Lifespan

After awakening from its torpor, the fish will spawn in the spring or summer months. The exact timing depends on the water temperature and availability of food. Most species are broadcast spawners that release their eggs and sperm into the water to fertilize them. After attracting the interest of one or more mates, the female will lay her eggs on plants in shallow water. A typical 8 or 9-pound fish can produce up to a million eggs at a time. Around 80% of them will end up hatching, but the vast majority of these are expected to be lost through predation and attrition.

The eggs hatch after three to eight days while still attached to vegetation or other objects. The young fry will consume the remaining egg yolk over the next few days and remain concealed in the vegetation to hide from predators and protect themselves from the current. After growing rapidly, the fry will soon graduate to consuming small plankton and water fleas. The fry must learn to swim and build up sufficient fat reserves before winter sets in. After departing the shallow waters, they join schools of fellow fish and continue to grow at pace. Carp have a long life expectancy of more than 40 years in captivity, but they don’t reach sexual maturity until the third year of their lives.

Fishing and Cooking

The carp remains a fairly popular fish for both commercial and recreational purposes, but it can be a little finicky to hook even with standard bait and sometimes require special fishing methods to catch. The crucian carp, for instance, tends to nudge the bait slowly instead of gulping the bait down at once. It’s a much easier practice to rear carp in artificial aquacultures for food. The silver carp and grass carp are specifically raised in this manner.

The carp features prominently in some Asian and European cuisine. Breaded or fried common carp is a traditional Christmas Eve dinner in Poland, Slovakia, and the Czech Republic, while the Chinese mud carp is sometimes eaten in Guangdong Province. In Western Europe, however, more desirable fish like salmon and trout have displaced it. This oily fish has acquired a bad reputation for tasting like mud, but it might be possible to eliminate the muddy taste by keeping the body temperature cool after catching it.

Evolution and Origin

As already mentioned, carp are freshwater fish that first evolved in the lakes, rivers, and ponds of Europe and Asia. The ancestor of the common carp most likely originated in the Black, Caspian, and Aral seas and swam east into Siberia and China.

We know that the Romans are the first to culture carp, which continued into the Middle Ages. It is through human intervention that these fish were later added to other waterways to help with certain environments, but the fish themselves then became invasive and needed to be controlled. In parts of the United States, it is called a pest fish and some areas spend thousands of dollars to keep them under control.

Some types of carp are bred in such a way as to be ornamental fish, as we see with goldfish and koi. The koi can fetch a good amount of money, often seen as “floating flowers” or a “flowing kimono”.

1. Britannica, Available here: https://www.britannica.com/animal/carp-fish-species
2. Carp Fishing Tactics, Available here: http://www.carp-fishing-tactics.com/science-carp-reproduction.html