Here, we present ultragentle soft robotic actuators capable of grasping delicate specimens of gelatinous marine life. Although state-of-the-art soft robotic manipulators have demonstrated gentle gripping of brittle animals (e.g., corals) and echinoderms (e.g., sea cucumbers) in the deep sea, they are unable to nondestructively grasp more fragile soft-bodied organisms, such as jellyfish. Through an exploration of design parameters and laboratory testing of individual actuators, we confirmed that our nanofiber-reinforced soft actuators apply sufficiently low contact pressure to ensure minimal harm to typical jellyfish species. We then built a gripping device using several actuators and evaluated its underwater grasping performance in the laboratory. By assessing the gripper’s region of acquisition and robustness to external forces, we gained insight into the necessary precision and speed with which grasping maneuvers …