Groping Slither-Slider

Splitting from its ancestor, the groping slither-slider has grown 2x larger than its ancestor. Its skin has changed color to blend in with golden sand, losing its photosynthesis in the process. It no longer swims, so its fins have split into legs that lets it crawl across the sea floor, albeit slowly. It eats detritus that is in the sand, so has evolved three tentacles that push sand into the mouth, which is under the body. Its eye is always on the lookout for predators, if it sees one, it will stop moving and pretend to be a lump of sand. They swarm in large groups on the seafloor.