Biology of grass carps
Grass carp (Ctenopharyngodon idella) is a herbivorous freshwater fish species that belongs to the family Cyprinidae. Grass carp is also known by different common names such as white amur, silver amur, and Chinese carp. The species is native to Eastern Asia, including China and Russia, and it has been introduced globally as a bio-control agent to regulate aquatic weeds. The following are some key biological features of the grass carp:
1. Morphology: Grass carp has a distinctive streamlined body shape with large scales, a pointed snout, and a slightly underslung mouth for grazing on aquatic vegetation.
2. Size: Grass carp can attain a maximum length of about 4 feet and a weight of over 60 pounds. However, the average size of grass carp is usually around 20-30 pounds.
3. Reproduction: Grass carp reach sexual maturity at around 2-3 years of age and spawning generally occurs in spring or early summer. They lay adhesive eggs in shallow water, and the eggs hatch within 4-7 days.
4. Diet: Grass carp are herbivorous, and their diet primarily consists of a variety of aquatic plants, including duckweed, water hyacinth, and watermeal. They have a unique pharyngeal apparatus that helps them grind their food, including plant material, into fine particles.
5. Habitat: Grass carp prefer warm, quiet, and shallow water bodies such as ponds, lakes, and slow-moving rivers, with abundant vegetation for feeding and protection.
6. Lifespan: Grass carp have a relatively long lifespan, with some individuals living up to 20 years.
Grass carp have been introduced globally in several water bodies for their bio-control properties against invasive aquatic plants. However, their introduction can sometimes lead to negative impacts on native aquatic species and habitats. Therefore, it is important to manage and control the populations of grass carp to minimize unintended consequences.