Scientists have captured very rare footage of a particularly unusual type of fish off the coast of California.
Known as a whalefish, this incredibly rare and elusive species - which was first discovered in 1895 - was spotted recently around 6,000ft beneath the waters of Monterey Bay by marine biologists from The Monterey Bay Aquarium Research Institute (MBARI).
It is so rare, that in the last 34 years, researchers at the institute have only seen one 18 times.
"Whalefish have rarely been seen alive in the deep, so many mysteries remain regarding these remarkable fish," the institue wrote in a Tweet.
"With each deep-sea dive, we uncover more mysteries and solve others."
The whalefish (of the order Cetomimiformes) is particularly unusual because throughout its life, it can appear as three distinct forms, thus making it seem like three separate species of fish.
All whalefish start out life as a tapetail - a scaleless larval form with a long, streamer-like tail.
If it is male, it then turns into a bignose - an unrecognisable form with a much smaller mouth. If it is female, the fish instead grows exponentially in size and exhibits bright orange coloration.
These changes are so dramatic that, for years, nobody even knew that they were the same species.