Silver Carp

• At the noise of outboard motors it leaps up to three metres clear of the water, and mass jumping has caused numerous injuries to boaters on the rivers of the American Midwest.
• Its filtering apparatus retains particles only a few microns across, which lets it live directly on phytoplankton without depending on animal prey.
• In its native range in China its wild populations have declined through dams and overfishing, while it runs riot as an invader on the other side of the world.
• It jumps. Startled by the noise of an outboard motor, it shoots out of the water to a height of up to three metres, and an adult carp can weigh 25 kg: collisions with boats and water-skiers have caused serious injuries.
• That behaviour is being studied as a control tool: broadband sound is being trialled to steer its movements and block its advance.
• It filters the water with extraordinarily dense gill rakers, which let it retain phytoplankton — particles far smaller than the bighead carp can exploit.
• It was introduced into the United States in the 1970s and 1980s as biological control for algae in fish farms and treatment plants. It escaped into the Mississippi during the floods of the 1990s and today dominates much of that basin.
• It competes directly with native mussels, fish larvae and the paddlefish for the same plankton.
• The IUCN classes it as Near Threatened in its native range in East Asia, while it is one of the worst invaders in North America: the same contrast as the lionfish.

Skeleton type

Vertebrate - internal bony skeleton (fish)

Habitat and environment

Large slow-flowing rivers and reservoirs

Sources consulted: Lista Roja de la UICN; US Fish and Wildlife Service; USGS; Vetter, Calfee y Mensinger; Kolar et al. (2007)