Behavioural Patterns and Interactions of Daphnia magna and Echinuriauncinata: Insights from Controlled Observations in Freshwater Habitats

Abstract

Within freshwater ecosystems, the ecological influence of keystone primary consumers cannot be overstated. Daphnia magna emerges as a particularly prominent player among such species, significantly impacting a biotic community's higher trophic interactions and nutrient dynamics. Therefore, the Daphnia magna’s presence within these habitats and its intricate interrelationships with other organisms are of critical importance in maintaining homeostasis and fostering functional, biodiverse environments. Despite the importance of studying such interspecies interactions, the coexistence of Daphnia with its endoparasite Echinuriauncinata remains enigmatic and largely unexplored in scientific literature. In this study, a series of controlled observation setups were designed to facilitate a comprehensive exploration of the behavioural patterns and interactions between Daphnia and Echinuria. Such observational platforms incorporated concave slide glasses, test tubes, Fresh squared bottles, and digital imaging analysis, enabling precise and detailed descriptions of the organisms' behaviours under varying culturing conditions. Our findings reveal a shared affinity for the benthic habitat, driven by the presence of sinking food particles. Despite the absence of overt competitive interactions for food resources, Daphnia displayed pronounced defensive behaviours, adeptly evading potential attacks from Echinuria. Temperature exerted discernible effects on their initial activities, with transient heightened responsiveness observed at elevated thermal conditions. Our investigations ultimately led to a hypothesis proposing an unintentional infestation scenario, wherein Daphia may unwittingly harbour Echinuria eggs or larvae, likely due to their size resemblance to floating food particles. These empirical insights contribute to understanding predator-prey relationships and inadvertent infestations, augmenting our comprehension of freshwater ecosystem dynamics and preserving these vital aquatic environments.