Marisa

Systematic position. The Marisa snail (Marisa cornuarietis) is a large freshwater snail belonging to the family Ampullariidae and the order Architaenioglossa. Unlike many other ampullariids, this species is known for its high trophic plasticity, meaning it can adapt its diet to include various plant materials, making it a significant threat to aquatic ecosystems.

Crops damaged. Marisa is an active phytophagous pest. It poses a substantial threat to aquatic and semi-aquatic plants grown in aquariums, greenhouses, and paludariums. It is particularly damaging to species such as Cryptocoryne, Echinodorus, Aponogeton, and young lily shoots, often consuming entire leaves and leaving only skeletal remains.

Biology and life cycle. The species is dioecious and reproduces by laying eggs in large clusters on underwater surfaces. Under favorable conditions, particularly in warm water with moderate hardness, the development of juveniles is rapid. The snail's ability to thrive in various artificial environments contributes to its success as an invasive species in many regions.

Damage patterns and economic importance. The damage is characterized by rapid tissue removal. Using a strong radula, the snail scrapes away leaf surfaces, often leading to the complete destruction of plant tissue. In high-density populations, the snail can denude an entire aquatic garden in a very short time, which causes significant economic loss in professional cultivation.

Protection measures. Management of Marisa includes manual collection of adult snails and removal of egg clutches from substrates. Chemical molluscicides are often impractical due to the potential toxicity to non-target organisms. Recommended strategies focus on biological control by introducing natural predators and maintaining strict control over the availability of food sources in the system.