Turtle Limpet (Cellana testudinaria) オオベッコウガサ also Opihi
The Turtle Limpet has a smooth shell and a tortoise shell pattern. They are found on rocks where there are waves. They eat alae and are very good at clinging to the rocks. Amami 2024
Here a Turtle Limpet is above what is most likely some sort of welk. The welk is predatory and the Turtle Limpet (Opihi) was able to outrun the welk. Amami 2023