Fairy shrimp

Fairy shrimp (genus Chirocephalus) are primitive branchiopod crustaceans that can pose a significant threat to young rice crops in specific agricultural environments. Despite their ecological importance in natural water bodies, in agricultural practice, they are considered pests that can inhibit the development of crop plants during the early stages of vegetation.

Systematically, this genus belongs to the order Anostraca and the family Chirocephalidae. These are small crustaceans, typically ranging from 1 to 3 centimeters in length. They lack a carapace, possess well-developed stalked eyes, and have numerous pairs of thoracic limbs that simultaneously perform functions of swimming, respiration, and food gathering.

The life cycle of the fairy shrimp is closely linked to temporary or stagnant water bodies, including flooded rice paddies. After a water body dries up, the shrimp's cysts (eggs) can remain viable in the soil for many years. When paddies are reflooded and reach specific temperature thresholds, the larvae hatch synchronously and develop rapidly, feeding on phytoplankton and microorganisms.

The damage caused by fairy shrimp involves mechanical harm to young rice seedlings. While foraging, these crustaceans can injure the roots and delicate tissues of young plants and cause water turbidity. Increased turbidity reduces photosynthesis in the young seedlings, leading to stunted growth, reduced plant density, and, consequently, lower overall yields.

Effective management strategies combine agrotechnical and chemical measures. Proper leveling of rice paddy surfaces is crucial to eliminate deep pockets of standing water. Additionally, early drainage or short-term drying of fields during critical stages of pest development is effective. In cases of massive outbreaks, the application of approved treatments that target crustaceans in the aquatic environment may be necessary.