Clinging to sunken debris in shallow, marine mangrove forests in the French Caribbean.

Tiny thread-like organisms.

Tiny thread-like organisms.

Perfectly visible to the naked eye.

Perfectly visible to the naked eye.

Have earned the title of the largest bacteria ever known.

Have earned the title of the largest bacteria ever known.

The bacteria clung to the leaves, branches, oyster shells, and bottles that sunk into the tropical swamp, Gros said in a press briefing.

Measuring around a centimeter long, they are roughly the size and shape of a human eyelash,

Measuring around a centimeter long, they are roughly the size and shape of a human eyelash,

In human terms, this is akin to coming across a person as tall as Mount Everest.

In human terms, this is akin to coming across a person as tall as Mount Everest.

Olivier Gros, a biologist at the University of the Antilles, discovered the prokaryotes in 2009