Cypriniformes

Cypriniformes is a massive order of ray-finned fish. This group includes many different families and genera. There are over 4,250 named species within this order. Some scientists list 11 to 12 families. Other experts identify as many as 23 families. These fish belong to a larger superorder called Ostariophysi. This group is incredibly diverse, especially in South and Southeast Asia. However, they are entirely absent from Australia and South America.

Members of Cypriniformes have unique physical traits. Like other Ostariophysi, they possess a Weberian apparatus. This is a specialized structure used for hearing. Most other Ostariophysi have a small, fleshy adipose fin on their backs. Cypriniformes differ because they only have a single dorsal fin. They also have a unique kinethmoid. This is a small median bone located in the snout. Most importantly, these fish lack teeth in their mouths. Instead, they use pharyngeal teeth located in their throats. These teeth grind food against a chewing pad at the base of the skull.

The order is divided into distinct suborders. The Cyprinoidea suborder contains carps and minnows. This includes the massive Cyprinidae family and the Psilorhynchidae family. The Cobitoidei suborder includes many different groups. It contains families like the Botiidae, which are pointface loaches. It also includes the Cobitidae, known as true loaches. Other families in this suborder include the Balitoridae, or hillstream loaches. There are also the Catostomidae, which are known as suckers.

History and discovery have changed how we view these fish. Scientists once thought they originated in Southeast Asia. However, new fossil evidence was found in 2025. Researchers identified fossils in the Prince Creek Formation in Alaska. These fossils date back to the early Maastrichtian age, roughly 71 to 69 million years ago. This suggests they may have started in high-latitude regions. They might have moved south during the Cenozoic era. The earliest known cypriniform fossils are the extinct Jianghanichthyidae from China.

The diversity of this order is quite large. The Cyprinidae family alone makes up two-thirds of all Cypriniformes. This family is found across Eurasia, North America, and Africa. While most are freshwater fish, some live in brackish water. The Pacific redfin is a rare species found in saltwater.

In terms of lifespan, the bigmouth buffalo is a record holder. It is documented to have lived for 112 years.

Cypriniformes have many connections to human life. Many species are vital food sources in Europe and Asia. Others are popular in the aquarium trade. Goldfish and koi are two of the most famous examples. Some species, like the common carp, have been introduced to all continents except Antarctica. These introduced species can sometimes harm environments. For example, carp can stir up riverbeds and reduce water clarity. This makes it difficult for plants to grow.

In the world of science, one fish is especially famous. The zebrafish, or Danio rerio, is a vital model organism. Scientists use zebrafish in biological and biochemical research. They are used to study how vertebrates develop and function. This makes them essential for understanding complex biological systems. The study of Cypriniformes helps us understand the broader evolution of the Ostariophysi superorder. This includes their relationship to characins, electric eels, and catfishes.