Unravelling the regional and global invasive potential of an emerging but overlooked invader: the pet-traded freshwater shrimp Neocaridina davidi

• Applicant: Dr. Sebastian Prati
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 564285756

Invasive species, particularly in freshwater ecosystems, pose a significant threat to global biodiversity, often causing rapid reductions in native species abundance and local extinctions due to strong predation dynamics and competition. This seems to be the case for emerging invasive species such as the subtropical atyid shrimp Neocaridina davidi a freshwater shrimp of Southeast Asian origin widely available in the global market. Its high reproductive rate and adaptability allow it to thrive in various environments, adversely affecting local meiofaunal communities and competing with native species. Furthermore, N. davidi can alter the energy and nutrient availability in stream ecosystems and introduce pathogens of great ecological and economic relevance. Feral populations of N. davidi have been reported worldwide. In temperate regions, they are primarily found in thermally impacted waters, where they can survive despite a wide range of native and invasive predators. However, feral N. davidi have been observed in water temperatures as low as 6° C in central Europe. Feral N. davidi populations are expected to expand, aided by climate change. Despite N. davidi's known and potential impacts in invaded areas, ist popularity in the pet trade, and ist increasing use as a model organism for behavioral, physiological, and ecotoxicological studies, current research has not addressed the invasive potential on a global scale, nor intraspecific variation in thermal and salinity tolerances (single and combined), persistence in colder climate under fluctuating temperature regimes, and potential dispersal in marine environments. Therefore, in this project, I want to assess the thermal and salinity tolerances of N. davidi using individuals with different life histories to build physiologically informed global and regional species distribution models and mechanistically elucidate how this and other warm-adapted invaders can thrive and disperse in dynamic environments that are colder or saltier than the native ones. The information generated in the proposed project will fill existing knowledge gaps and provide essential data for laboratories using N. davidi as a model organism, benefit stakeholders involved in managing this species, and inform policymakers on ist current and future spread. Furthermore, this project will offer a mechanistic framework to study invasion processes in other ectotherm species.

• DFG Programme: WBP Fellowship
• International Connection: France, Poland
• Participating Institution: University of Lodz; Department of Invertebrate Zoology and Hydrobiology; Université de La Réunion
• Hosts: Dr. Aleksandra Jablonska; Professor Sébastien Jaquemet