This story was originally published by Vox and is reproduced here as part of the Climate Desk collaboration.

It lives in a glass castle deep under the sea.

It’s not a character from The Little Mermaid but a very real, very mysterious marine worm. Known as Dalhousiella yabukii, the worm resides inside a glass sea sponge—a simple marine animal that forms a glass-like skeleton—in the cold, dark waters off the coast of Japan. And it’s just one of a massive trove of marine animal species that scientists say they recently discovered.

This week, the Ocean Census—a project that has set out to accelerate the discovery of sea life—announced that it has found 1,121 previously unknown ocean species since last April. That marks a massive jump in the number of newly discovered marine species in a single year, according to Oliver Steeds, director of the Ocean Census, a joint mission of the UK-based nonprofit Nekton and Japan’s largest philanthropic organization, the Nippon Foundation. Some of the other newly found creatures include fish, rays, sponges, and soft corals (you can see more of them below).

Though it may seem that Earth is already largely explored, the vast majority of animal species on Earth—perhaps as many as 90 percent of them—remain undescribed. “This is really a planetary blindspot,” said Steeds, who’s also the founder and chief executive of Nekton.

The Ocean Census, which launched three years ago, is trying to close the gap in the marine realm by exploring remote ocean regions with the help of high-tech submersibles and taxonomists. And to that end, this large batch of species is an important step forward—with one major caveat.

While the search for life beyond Earth has been a magnet for public attention, missions like the Ocean Census reveal that there is a lot we still don’t know about life on our home planet—much of which looks pretty darn alien.

Most critters that the expeditions revealed are pretty small, like this striking ribbon worm. Found in the waters near Timor-Leste in Southeast Asia, the worm’s bright colors may be a........

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