Amur sleeper

The Amur sleeper (Perccottus glenii) is an invasive fish species belonging to the order Perciformes and the family Odontobutidae. Although classical agronomy treats it as a pest of fisheries and pond aquaculture, it is a serious biological pollutant capable of causing significant damage to ecosystems used for irrigation and fish farming.

The biology of this species is characterized by exceptional plasticity. The Amur sleeper is capable of surviving in the most unfavorable conditions: in heavily silted, drying, or frozen-to-the-bottom water bodies where other fish species perish. During the spawning period, the female deposits eggs on underwater objects or vegetation, and the male actively guards the clutch, ensuring the survival of the offspring even under low oxygen levels.

The main damage caused by this species is due to its predatory lifestyle. The Amur sleeper feeds on the eggs, larvae, and fry of valuable commercial fish species, and also destroys the food base (zooplankton and benthos) necessary for the normal growth and development of cyprinid fish. When colonizing a pond farm, the Amur sleeper rapidly displaces native species, leading to the degradation of the biocenosis and a reduction in the water body's productivity.

The character of the damage manifests itself in the total suppression of other fish populations in closed water bodies. Due to high fertility and low maintenance requirements, the Amur sleeper quickly overpopulates ponds, turning them into a monoculture. This leads not only to economic losses for fish farms but also to a disruption of the biological balance in adjacent drainage canals.

Control measures include a comprehensive approach based on hydrotechnical and biological protection methods. These include:

• Complete drainage and freezing of pond beds in winter to destroy eggs and adult specimens.
• Use of fine-meshed nets when filling water bodies to prevent the entry of juveniles.
• Stocking water bodies with active predators, such as pike, which help control the Amur sleeper population.
• Application of specialized ichthyocides, where permitted by local regulations.