This Rare Jellyfish Lives 13,000 Feet Below the Ocean’s Surface — and it Looks Like a Fireworks Display

Most deep-sea creatures look like something from the underworld. Their oversized eyes, bizarre bodies, and unusual movements are testaments to evolution. In this YouTube video, we see another species that has adapted to life far below the ocean’s surface: Halitrephes maasi, otherwise known as the firework jellyfish. Though it lives deeper than many others, its appearance isn’t frightening—in fact, it’s beautiful.

A Jellyfish Illusion

The firework jellyfish was first recorded in 1909. Since then, sightings have been incredibly rare. They live at depths mostly devoid of oxygen, where sunlight doesn’t penetrate. At its home 13,000 feet beneath the surface lies the bathypelagic zone, also known as the “midnight zone.” Here, the temperature never rises above 40 degrees Fahrenheit, and divers would experience more than 5,850 pounds of pressure per square inch if they could survive the dive. This zone is uninhabitable for most of Earth’s species but perfectly suited for the firework jellyfish.

Very few jellyfish can survive at this depth. The firework jellyfish is in the company of the giant phantom and Atolla jellyfish, both living in the midnight zone. What sets the firework jellyfish apart is the unique display for which it’s named. Bioluminescence is common in the animal kingdom, but the way the firework jellyfish uses it is unique. The colors you see on camera are brought to life by the light reflected from the crew’s equipment. In reality, this jellyfish is virtually colorless as it floats unnoticed. The crew of the Nautilus, who took this video, explained to This Is Colossal, saying, “Radial canals that move nutrients through the jelly’s bell form a starburst pattern that reflects the lights of ROV Hercules with bright splashes of yellow and pink.” Without external light, this jellyfish would never be seen, helping it camouflage perfectly in its dark environment.

The Unique Discovery

Not much is known about these types of jellyfish. Sightings of this unique species have only occurred in the Pacific, Indian, and South Atlantic Oceans. This footage captured by the Nautilus was completely accidental, as is often the case with rare species. During a routine crab excursion, the crew’s camera caught this beautiful jellyfish just over 4,000 feet off the coast of Baja California. As is evident in the video, the discovery was just as surprising to them as it likely was to the jellyfish. If it had not been for the light of the remotely operated vehicle, this jellyfish may have just been a blur of dark blue underwater.

The discovery of this jellyfish off the coast of Baja California also reveals some of its nature. It may look delicate, but deep-sea jellyfish like this must endure many hostile environments to swim as far as they do. This speaks to the species’ survival rate and how easily it can adapt to changing environments from one region to the next. This is helped by its unique body shape, which is designed to propel it through water quickly. Its anatomy is simple, with only one opening that serves as both the mouth and the anus.

Colors Are a Natural Defense

As you see in the video, the firework jellyfish is quite active, even at these depths. This also applies to hunting, at which it’s relatively adept. Like other deep-sea hydrozoans, the firework jellyfish uses its tentacles to capture prey. Its diet mainly consists of plankton, smaller fish, and even other jellyfish. The venom of this species is unclear, since no one has ever gotten close enough to be stung. Its sting would likely be incredibly painful, as it’s part of the Hydrozoa class, which includes the infamous man-of-war. The difference between the two is their evolution; the man-of-war remains in its polyp form, while the firework jellyfish grows into a true medusa, or jellyfish.

Hydrozoan jellyfish are carnivorous and rely heavily on their tentacles to catch prey. In the case of the firework jellyfish, its bioluminescence also serves as a hunting tool. Small fish and other jellyfish are often attracted to its light. By the time they realize what’s happening, it’s usually too late, and the jellyfish has been caught. Hydrozoan jellyfish have tentacles coated with cnidocytes, producing toxins that paralyze their prey. Alternatively, bioluminescence can also be a defense mechanism. Illumination at depths like the midnight zone can potentially spook predators. This ability is similar to the vampire squid’s, which produces a liquid that luminesces when it’s in danger. Although scientists haven’t witnessed the firework jellyfish in action, it can be surmised that its neon coloring works similarly to distract predators.