Burrowing sea urchin Echinometra sp., in a burrow formed in living coral. These organisms also destroy immense tracts of beach rock and other hard substrate. In high energy algal reefs, these animals live in the coralline algae, their burrow helping dissipate the wave energy that impinges on the reef. If a research scientist happens to slip and fall on such a reef, the spines of Echinometra can inflict major damage to the human anatomy. Wet jackets are recommended when working on these reefs. Informally, this animal is called the "lilt red rock eater."