How do pteropods use modified feet like wings to swim?

Pteropods are small marine gastropods belonging to the phylum Mollusca that have adapted their foot into a pair of winglike flaps known as parapodia.12

These modified structures serve as the primary swimming organs for these pelagic animals, allowing them to navigate their environment at or near the sea surface. By moving these winglike flaps, pteropods are able to swim through the water column. While other mollusks, such as cephalopods and scallops, rely on jet propulsion or undulatory movements for locomotion, the pteropod's specialized foot modification provides a distinct method of movement suited to their small size and lifestyle.1234