Praya dubia

Praya dubia, the giant siphonophore, lives in the mesopelagic zone to bathypelagic zone at 700 m (2,300 ft) to 1,000 m (3,300 ft) below sea level. It has been found off the coasts around the world, from Iceland in the North Atlantic to Chile in the South Pacific.

Praya dubia is a member of the order Siphonophorae within the class Hydrozoa. With a body length of up to 50 m (160 ft), it is the second-longest sea organism after the bootlace worm. Its length also rivals the blue whale, the sea's largest mammal, although Praya dubia is as thin as a broomstick.

A siphonophore is not a single, multi-cellular organism, but a colony of tiny biological components called zooids, each having evolved with a specific function. Zooids cannot survive on their own, relying on symbiosis in order for a complete Praya dubia specimen to survive.