Silent scream

When attacked by a predator, this deep-sea jellyfish (Atolla wyvillei) uses bioluminescence to “scream” for help. The amazing light show is known as a burglar alarm display. This jellyfish was photographed by the ROV Hyper Dolphin east of Japan’s Izu-Oshima Island, 2,640 feet (805 meters) below the surface.

Octopus in the Gulf

A deep-water octopus (Benthoctopus sp.) sits on the seafloo in the Gulf of Mexico’s Alaminos Canyon, about 8800 feet (2700 meters) beneath the sea surface.

Neighbor to an oil rig

This queen angelfish (Holacanthus ciliaris) was spotted near an oil rig in the Gulf waters off the coast of Texas.

Cooper of the Sea

This Gulf of Mexico amphipod, Phronoma sedentaria, is known as the “Cooper of the Sea” because the crustacean species lives inside a barrel-shaped creature known as a salp, also shown here.

King of the hydroids

Branchiocerianthus imperator is the largest known type of solitary hydroid. Hydroids look like flowers, but they’re actually animals with tentacles. This one was spotted by the HOV Shinkai 2000 in Japan’s Sagami Bay at a depth of 2,200 feet (670 meters).

Star of the sea

Asteronyx loveni is a type of brittle star that tends to cling onto another marine species known as the sea pen. This brittle star was spotted with its arms flung wide in Japanese waters off Sanriku, at a depth of 4,150 feet (1,265 meters).

Spiky spider

The spider conch (Lambis chiragra) has six spines on the lip of its shell. The shell’s pearly interior displays beautiful tints of orange and yellow. The species is listed as “vulnerable” on the Red List of threatened animals of Singapore.

Paper bubble

This red-lined paper bubble (Hydatinidae gen. sp.) was discovered in a sperm whale carcass in the Kagoshima whale fall, off Japan’s Cape Nomamisaki. The gastropod’s tiny eyes are protected by cephalic shields. The “paper bubble” is actually an extremely thin shell.

Dangerous beauty

The giant Caribbean anemone (Condylactis gigantea) grows to a height of about 6 inches (15 centimeters). Its tentacles are beautiful … but they contain toxin-bearing nematocysts that paralyze the sea anemone’s prey.

Fire in water

The bearded fireworm (Hermodice carunculata) is a type of bristleworm, with groups of white bristles along each side. The venom-filled bristles easily penetrate the flesh and break off if this worm is handled. They produce an intense burning sensation in the area of contact, hence the common name of the Caribbean species.

Spongebob’s buddy

These nocturnal echinoderms (Ophiothrix suesonii) are called sponge brittle stars. They are very common in the Caribbean. They are so named because they are found exclusively either inside or outside living sponges.

What big teeth!

Imagine living in the sea where it is permanently dark, cold, and food is hard to find. For many animals at depth, it may be weeks to months between meals. If you find something to eat, you have to hang on to it. This is why so many deep-sea fishes have lots of big teeth. This dragonfish, spotted off the coast of Australia, even has teeth on its tongue. They would be terrifying animals … if they weren’t the size of a banana.

Fish with a lure

The sargassumfish (Histrio histrio) is a member of the frogfish family (Antennariidae), a group of small, globular fishes with stalked, grasping, limblike pectoral fins with small gill openings behind the base, a trapdoor-like mouth high on the head, and a “fishing lure” (formed by the first dorsal spine) on the snout. It typically lives in open waters in close association with floating sargassum weed (Sargassum natans and S. fluitans) but is frequently blown into nearshore and bay waters during storms. This specimen was found off the coast of Korea.

Kooky cucumber

This newly discovered sea cucumber species, Elpidia belyaevi, was first found in the Arctic deep sea.