Description and characteristics
The grass carp (Ctenopharyngodon idella) is a large cyprinid with an elongated, fusiform body covered with large scales. It has a grey-green back and silvery flanks.
Habitat and distribution
It prefers warm, vegetated waters, being introduced into lakes and ponds of the Danube Delta to control aquatic plants. It tolerates varied water temperatures.
Diet and behaviour
It is a strict phytophage, feeding almost exclusively on large aquatic plants. It can consume large amounts of vegetation, being used to clean canals and eutrophic ecosystems.
Reproduction
Spawning occurs in flowing waters in spring, with females laying pelagic eggs. In ponds, natural reproduction is rare, so it is bred in aquaculture.
Economic and ecological importance
It has value in aquaculture and for biological control of aquatic vegetation. It is widely consumed. Ecologically, it can however modify ecosystems if introduced excessively.
Threats and conservation
It is an introduced species, and its impact on native ecosystems must be carefully managed. Excessive vegetation consumption can affect the habitat of other species.
Fishing and legal minimum size
It is fished commercially and for recreation. In the table of minimum legal sizes, the grass carp (Ctenopharyngodon idella) has a minimum legal size of 40 cm.
Conclusion
The grass carp is a phytophagous cyprinid used to control vegetation, important in aquaculture and fishing.