Impact of Dopamine Agonist on Locomotion Pattern of Daphnia Magna

Daphnia Magna, a small freshwater planktonic crustacean, plays a crucial role in various ecological, toxicological, and pharmacological studies. They propel themselves through water using powerstroke motion, by periodically beating their antennae. Despite their significance, the description of Daphnia motion has primarily been qualitative or vaguely quantitative. Our study aims to offer a detailed granular-level analysis of Daphnia locomotion. We observed their free-swimming motion in a quasi-2D chamber as well as the motion of their antenna in a tethered state. The extracted positional, temporal, and orientation data using a deep learning software - SLEAP, helped us categorize different gaits of daphnia magna. To further study the impact of these gaits on the dynamics, speed, and efficiency of swimming, we treated these organisms with a dopamine receptor agonist. This drug is known to decrease the average swimming speed of the daphnids, however, the exact physical mechanism by which that happens remains unclear. Our study aims to identify the features of the swimming gait that lead to the emergence of distinct mobility patterns that decrease their overall speed.