Pyrosoma atlanticum

Looking somewhat like the planet-killing
Doomsday Machine from the original Star Trek series,
a colony of tunicates forms an open-ended tube,
through which it filters the surrounding waters
for the phytoplankton upon which it lives.

An infrequent visitor to La Jolla Canyon (within safe diving limits), these animals usually
confine themselves to the deep waters.
One day we found hundreds
of small colonies, averaging about
2 to 3 inches (7 - 10 cm.) in length.

The colony pictured above, however, was huge -- approximately 4 feet (3.3 m.) in length,
and about 4 inches (14 cm.) in diameter.

This is nothing compared with one
recently seen by another diver.
Click here for photos from his video

The colony below is typical, displayed at about life-size:

For more views of these unusual animals, click here.