Afloat Together: Aquatic Worms Utilization of Duckweed for Collective Locomotion

California blackworms (Lumbriculus variegatus) are freshwater aquatic worms that thrive in low-oxygen benthic zones. These worms can collectively aggregate, forming cohesive “blobs.” In environments where the water surface is covered by floating plants such as duckweed, blackworms ascend upwards by entangling with the plant’s roots. We observe that worm blobs can utilize these floating structures to potentially aid in locomotion, foraging, and predator avoidance. In this talk, we explore the multifaceted roles played by duckweed and blackworms in their ecology. We hypothesize that utilizing duckweed allows for more efficient collective locomotion due to the reduced friction which we validate through image analysis. Furthermore, we conduct a force balance to measure the amount of buoyancy force that duckweed can provide to a population of worms which we validate using a force sensor. Our study between blackworms and their interactions with duckweed not only enhances our understanding of their ecological dynamics but may also underscores the significance of their biophysical phenomena in complex ecosystems.