1. Glass Sponge: Nature's Glass Artisans

Meet the glass sponge, a fascinating creature that defies its name. While it’s not crafted from glass, it thrives without a mouth, eyes, or stomach, relying on its silica-based skeleton—similar to glass—to exist. Once thought extinct, live glass sponge reefs were rediscovered off British Columbia in 1987, showcasing ecosystems dating back 9,000 years.

Found deep in the ocean at about 3,000 meters, these reefs, surprisingly located at shallower depths (approximately 300 meters) in North America, play a crucial role in marine life by providing shelter for over 120 species and filtering water of bacteria. Unfortunately, their slow growth means that damage from fishing or mining can lead to irreversible loss, necessitating the establishment of a 2,410-square-kilometer marine protected area to safeguard their delicate environment.

2. The Bloody-Belly Comb Jelly: A Mysterious Dancer of the Deep

Living in the twilight zone of the ocean, the bloody-belly comb jelly captivates with its vibrant red hue. Found at depths ranging from 250 to 1,500 meters off Canada’s Pacific Coast, this unique creature uses its coloration effectively; in the deep waters, where red appears black, it camouflages itself while lurking for bioluminescent prey.

Unlike jellyfish, this creature shuns stingers, instead relying on its eight rows of cilia for movement and feeding, making it the largest of such ciliated beings.

3. Greenland Shark: The Ancient Giant

The Greenland shark is a living legend, boasting ages that can reach up to 500 years. This slow-moving behemoth can grow between three to five meters in length and survives mostly on deep-sea prey, like squid and seals—often while sleeping!

Notably, the shark’s meat is toxic, steeped in Inuit folklore. Yet, through fermentation, it transforms into hákarl, a traditional Icelandic dish. With its remarkable adaptability, the Greenland shark remains an enigmatic figure of the sea.

4. Giant Isopods: The Armored Giants of the Deep

Giant isopods, akin to pill bugs but 16 times larger, showcase a phenomenon known as deep-sea gigantism. While the reasons behind this phenomenon remain unclear, hypotheses suggest that larger beings may find energy efficiency amid the sparse food supply of the deep sea.

These colossal creatures scavenge the ocean floor, consuming leftovers with impressive size and tenacity.

5. The Elusive Giant Phantom Jellyfish

With a striking length of up to nine meters, the giant phantom jellyfish embodies the mysteries of the ocean. Rarely observed—only 120 times since its discovery in 1899—its transparent, ghostly body and ribbon-like arms allow it to snare fish in its powerful embrace.

Despite its size, the giant phantom jellyfish is not harmful, as it lacks traditional stinging tentacles, instead employing its unique structure to predate on plankton and small fish while evading larger marine predators.

6. Dumbo Octopus: The Deep-Sea Darling

Possibly the cutest deep-sea dweller, the Dumbo octopus earns its name from its ear-like fins that allow it to swim gracefully through abyssal waters. First studied during the famous Challenger expedition (1872-1876), this enchanting creature has about 17 identified species, adapting splendidly to the dark, cold depths with its lack of an ink pouch.

Celebrated for its role in raising awareness about deep-sea ecosystems, the Dumbo octopus symbolizes the wonders that still await discovery in our oceans.