Asian Carps
ISC Inner Banner
Homebreadcrumb separatorASIAN CARPSbreadcrumb separatorGrass Carp

Grass Carp

(Ctenopharyngodon idella)

Physical Description

The body of Grass Carp is oblong shaped with a slightly flattened head and moderately small eyes centered on the side of the head. They are covered with large cycloid scales and colouration varies from blackish to olive-brown with brassy or silvery-white on the sides and belly. Scales on the back and sides are outlined by pigment giving a cross-hatched effect.

Preferred Habitat

Grass Carp prefer large, slow flowing water bodies and spawn in large rivers with moderate currents. Egg survival and larval development is best in waters at 18⁰C but adults can tolerate temperatures between 0-38⁰C.

Diet

They feed on aquatic plants but can also consume detritus, insects, small fish, earthworms and other invertebrates in the absence of aquatic vegetation. Grass Carp can consume up to 40% of their body weight per day and can significantly alter the composition of habitat by reducing food sources, shelter and spawning areas for native fish. Also, because they can only digest about half of the plant material that they consume each day, the remaining material is expelled into the water, enriching it and promoting algal blooms. 

Size

Grass Carp mature in about 1-10 years and reach a maximum size of over 50 kilograms.

 

 

Image of a Grass carp

Illustration © Joseph Tomelleri

Fast Facts:



Origin: Large rivers and lakes in eastern Asia from southern Russia to northern Vietnam. 

Diet: Feed on aquatic plants but can also consume detritus, insects, small fish, earthworms and other invertebrates .

Life Span: 5 - 11 years  

Size: Maximum: 45 kg, 1.5 meters

Did You Know?

Grass carp can only digest about half of the plant material that they consume each day, the remaining material is expelled into the water, enriching it and promoting algal blooms.

Size Relative to 6ft Man:


Comparison of size between a grass carp and a 6ft tall human


Grass carp in the water


Spread of Grass Carp (1994 – Present)

 

Spread of Grass carp in America since 1994

 

Map courtesy of the United States Geological Survey