For likely the first time,sex video play biologists captured a wild, elusive ram’s horn squid, or Spirula spirula, live on video.

The deep ocean — particularly the twilight zone, a dark realm extending some 660 to 3,300 feet below the surface — is little known and woefully unexplored. When navigating the depths in submersibles or using remotely operated vehicles (ROVs), marine biologists can spot rarely (or never) seen creatures. In late October, a Schmidt Ocean Institute expedition filmed the Spirula spirula floating vertically at some 2,850 feet underwater.

"Exciting news!" the institute, which explores the ocean, tweeted on Oct. 27. "This appears to be the FIRST observation of Spirula, aka ram's horn squid, alive + in its natural environment. Very rarely seen or captured, they have many extinct relatives, but are only living member of genus Spirula, family Spirulidae, and order Spirulida."

Top squid experts, like Michael Vecchione, a cephalopod expert at the Smithsonian Institution, had never before seen the ram’s horn squid in its natural world.

At 54 seconds into the 55-second clip below, the squid exhibits its astonishing speed, as it bolts out of the frame.

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The ram’s horn squid is so named for the shape of its coiled, interior shell, which the animals use to control their buoyancy in the ocean. The intriguing shells wash up on beaches, and some are sold online.

The ocean's twilight zone is a continually remarkable place, with remarkable squids. Curious, rarely seen giant squids have approached flashing lures in the dark water. And marine biologists recently found evidence that a large shark and squid fought in the deep sea, after finding telltale sucker marks on the shark's body.

"It’s the majesty of nature,” Nathan Robinson, a researcher at the Oceanogràfic Foundation, a marine conservation organization, told Mashable about the deep sea tussle.