In an aquarium, these invertebrates are part of the cleaner crew “category” as they participate in the process of keeping the balanced ocean-like environment needed for your fish and corals to thrive.
Sea cucumbers are echinoderms—like starfish and sea urchins. There are some 1,250 known species, and many of these animals are indeed shaped like soft-bodied cucumbers. All sea cucumbers are ocean dwellers, though some inhabit the shallows and others live in the deep ocean. They live on or near the ocean floor—sometimes partially buried beneath it.