When threatened, sea cucumbers violently contract their muscles and discharge some of their internal organs out of their anuses. The discharge will confuse the enemy and give it a hearty meal, giving the sea cucumbers an opportunity to escape. The missing body parts can later be regenerated. In addition to this form of defense, they can also release dense and sticky white filaments to entangle their predators.

Sea cucumbers (Holothuroidea), which look like soft-bodied cucumbers, are echinoderms. All sea cucumbers are ocean dwellers, though some inhabit the shallows and others live in the deep ocean. They live on or near the seafloor. 

They feed on plankton, algae and decaying matter. When sea cucumbers scavenge the seafloor for their food, they also ingest lots of sand.

Actually, sea cucumbers are very fragile. When a sea cucumber leaves the water or is exposed to high temperatures and oil, the enzyme in its body activates, which will dissolve itself into liquid within a few hours. 

According to China Daily, in August 2018, many parts of northeast China's Liaoning Province experienced high temperatures, with the highest temperature in some areas exceeding 40 degrees Celsius. Because of the high temperatures, many sea cucumbers melted in the water. The unusually high temperatures severely hit the sea cucumber farming industry.

About The Blue World series:

The ocean covers more than 70 percent of the Earth. In this blue world, there are all kinds of marine life with surprising abilities we don't know about. In this series, CGTN guides you through the journey of exploring the amazing animals in the ocean. 

For more:

The Blue World: The glowing sea

The Blue World: Far away from the shore

The Blue World: When two oceans meet

The Blue World: When a huge wave comes in

The Blue World: Black holes of the ocean

The Blue World: Sea cappuccino

The Blue World: Marine nightmare

The Blue World: Arms with special abilities

(All images via VCG)

(If you want to contribute and have specific expertise, please contact us at nature@cgtn.com.)