Fantasia

A type of sea cucumber found south of the Philippines leaves nothing to the imagination. The pink sea-through fantasia has a completely transparent body. That reveals its entire digestive system, from top to bottom.

The fantasia was discovered in 2007 as part of the Census of Marine Life. This decade-long project sent 2700 researchers from 80 countries on more than 500 expeditions, to all the world’s oceans. The scientists used robotic submarines and other equipment to seek forms of life that no one had ever seen before.

The 2007 expedition took a look at the Celebes Sea. It’s part of a region known as the Coral Triangle, in the western Pacific Ocean. Researchers from the U.S. and the Philippines photographed hundreds of living organisms, including many that no one had seen before. That included a type of worm that has tentacles that look like a squid’s.

The discoveries also included the fantasia, a type of sea cucumber. It was found at a depth of about a mile and a half. The fantasia feeds by filtering nutrients from sediments on the bottom. And while most sea cucumbers stay on the ocean floor, this one can swim. It uses a wing-like collar around its mouth to swim up into the water. It may use that ability to move to new feeding grounds, or to escape danger. And like many deep-sea creatures, it produces its own light -- a soft glow that illuminates its innards. That may scare away possible predators, which might not want to see the insides of their next meal.