Movie 1.

Description: A swimming trial was conducted on Natrix M to analyze its swimming kinematics. The snake was observed swimming in a stationary water tank, with filming conducted from below at a high-speed rate of 1000 fps. The resulting video footage was subsequently slowed down using a factor of 100/6. During this swimming trial, the snake kinematic parameters were measured as follows: U = 0.92 Ls^-1, f = 2.5 Hz, A = 0.15 L, λ = 0.43 L.