Deep-sea Cucumber Laetmogone violacea
In the deep ocean, sea cucumbers are one of the dominant sea-floor groups all over the world. Laetmogone violacea is one of a large number of species that crawl over the soft, muddy ocean bottom eating organic detritus. The deep-sea cucumber's peglike “legs” may help to keep it from sinking too far into the mud. Ingested mud that the cucumber is unable to digest leaves its body as fecal casts, which may then be eaten again by other sea cucumbers. Like many deep-sea animals, the deep-sea cucumber is almost colorless but glows all over with bioluminescent light; exactly how the animal uses this light is not yet known. Some deep-sea starfish are known to light up when approached by a predator, which may scare it away. It may be that the deep-sea cucumber uses its bioluminescence in the same way.