MINNOWS, CARPS, AND RELATIVES: Cypriniformes

STONEROLLER (Campostoma anomalum): SPECIES ACCOUNTS
SILVER CARP (Hypophthalmichthys molitrix): SPECIES ACCOUNTS
CLOWN LOACH (Botia macracanthus): SPECIES ACCOUNTS

PHYSICAL CHARACTERISTICS

Minnows, carps, and loaches and their relatives have an upper jaw that can extend forward and a toothless mouth. The head is almost always scaleless. Some species have one to three rows of teeth in the throat with never more than eight teeth in any one row. Other species have more of these teeth but in only one row.

GEOGRAPHIC RANGE

Minnows, carps, and loaches and their relatives live in Europe, Asia, Africa, and North America.

HABITAT

Almost all carps, minnows, and loaches and their relatives live in freshwater.

DIET

Carps, minnows, and loaches and their relatives eat plants, insects, other fishes, plankton, and algae. Algae (AL-jee) are tiny plantlike growths that live in water and have no true roots, stems, or leaves. Plankton is made up of microscopic plants and animals drifting in the water and too small to be seen with the eye.

BEHAVIOR AND REPRODUCTION

When threatened by a predator, or an animal that hunts and kills other animals for food, some carps and minnows release a substance that causes the fishes nearby to scatter and hide. This reaction signals the rest of the group to avoid the predator. Some species of loaches use their mouths to attach themselves to the bottom and avoid being swept away by currents. Carps and minnows spawn, or release eggs, mostly in spring and summer. Many species spawn only once in a breeding season, but some spawn more than once.

MINNOW, CARPS, AND LOACHES AND THEIR RELATIVES AND PEOPLE

Carps and minnows are an important food fish. The zebrafish is one of the most important model fishes in genetics and medical research. Many carps and minnows, such as goldfish, are used in aquariums. Many loaches and their relatives are sold in pet shops because they are useful for keeping aquariums clean of algae.

BOTTOM FEEDERS

Bottom-feeding carps suck in sand and mud with their food. A basket-like structure between the mouth and gills holds the food particles but lets the dirt particles pass through. The fish spits out pebbles and sand too large to pass through the basket.

Did You Know?

Carps and minnows are the largest family of freshwater fishes.

CONSERVATION STATUS

The World Conservation Union (IUCN) lists seventeen species of minnows, carps, and loaches and their relatives as Extinct, one as Extinct in the Wild, forty-two as Critically Endangered; thirty-seven as Endangered; 116 as Vulnerable; seven as Lower Risk/Conservation Dependent; and thirty as Lower Risk/Near Threatened. Extinct means no longer alive at all; Extinct in the Wild means no longer alive except in captivity or through the aid of humans. Critically Endangered means facing extremely high risk of extinction in the wild in the near future. Endangered means facing very high risk of extinction in the wild in the near future. Vulnerable means facing high risk of extinction in the wild. Lower Risk/Near Threatened means at risk of becoming threatened with extinction in the future. Lower Risk/Conservation Dependent means that if the conservation program were to end, the animal would be placed in one of the threatened categories. The U.S. Fish and Wildlife Service lists twenty-six species as Endangered, or in danger of extinction throughout all or a significant portion of its range, and nineteen species as Threatened, or likely to become endangered in the near future.

STONEROLLER (Campostoma anomalum): SPECIES ACCOUNTS

Physical characteristics: Stonerollers reach a maximum length of about 9 inches (23 centimeters) but are usually about 4 to 6 inches (10 to 15 centimeters) long. The lower jaw has a shovel-like extension. Stonerollers are brownish with a brassy luster on the back. There is a dark vertical bar behind the gill cover, and the top and bottom fins have a dark crossbar about half way up. The rest of the fin is olive in females and fiery red in males in spring. In the spring, the head and sometimes the entire body of males are covered with large round bumps.

Geographic range: Stonerollers live in the eastern and central United States, southern Canada, and northern Mexico.

Habitat: Stonerollers live in fast streams with sand and gravel bottoms. They prefer areas where riffles and pools alternate in rapid succession.

Diet: Stonerollers mainly eat algae but also eat waste material and aquatic insects from rock surfaces.

Behavior and reproduction: In breeding season male stonerollers dig spawning pits by driving their heads into the gravel. They move gravel from the pits by nudging stones out with their snouts, which is why they are called "stonerollers," or by moving them with their mouths. Females remain in deeper water near the spawning pits and enter the pits individually or in groups to deposit eggs. The sticky eggs become lodged in the gravel and are abandoned before hatching.

Stonerollers and people: Stonerollers are not sought by fishermen.

Conservation status: Stonerollers are not threatened or endangered. ∎

SILVER CARP (Hypophthalmichthys molitrix): SPECIES ACCOUNTS

Physical characteristics: Silver carp are usually 12 to 16 inches (30 to 40 centimeters) long. They are brassy olive on the back and silver-white on the lower sides and belly. Silver carp have one row of bones in the throat that are used for crushing food.

Geographic range: Silver carp are native to China and eastern Siberia but have been introduced worldwide.

Habitat: Silver carp live in standing or flowing waters such as ponds, lakes, and rivers.

Diet: Silver carp eat plankton.

Behavior and reproduction: Silver carp are known for leaping clear of the water when disturbed. They often swim just beneath the water surface. These fish migrate to the middle or upper reaches of a river to breed. The eggs and larvae float downstream to floodplain zones.

Silver carp and people: Silver carp is an important food fish. In some areas silver carp are used mainly for cleaning bodies of water where excess algae is a problem.

Conservation status: Silver carp are not threatened or endangered. ∎

CLOWN LOACH (Botia macracanthus): SPECIES ACCOUNTS

Physical characteristics: Clown loaches have a deep body that is orange with three black stripes. They reach a maximum length of 12 inches (30 centimeters).

Geographic range: Clown loaches live in Indonesia, Thailand, and the Philippines.

Habitat: Clown loaches live near the bottom of streams.

Diet: Clown loaches feed on bottom-dwelling algae, weeds, worms, and crustaceans (krus-TAY-shuns), water-dwelling animals that have jointed legs and a hard shell but no backbone.

Behavior and reproduction: Clown loaches are not aggressive and spend most of their time at the bottom among plants. Clown loaches breed only at the beginning of the rainy season and do so in fast-flowing rivers.

Clown loaches and people: Clown loaches are popular aquarium fishes. They sometimes are eaten.

Conservation status: Clown loaches are not threatened or endangered. ∎

FOR MORE INFORMATION

Books:

Berra, T. M. Freshwater Fish Distribution. San Diego: Academic Press, 2001.

Gilbert, Carter Rowell, and James D. Williams. National Audubon Society Field Guide to Fishes: North America. New York: Knopf, 2002.

Schultz, Ken. Ken Schultz's Field Guide to Freshwater Fish. New York: Wiley, 2004.

Web sites:

"Cypriniform." All Science Fair Projects. http://www.all-science-fair-projects.com/science_fair_projects_encyclopedia/Cypriniform (accessed on September 24, 2004).