Deep sea basins are mostly flat, but in some places, hot lava penetrates the ocean floor then cools, creating submarine volcanoes which gradually increase in size. Some even get so large they rise to the surface after a while, which results in volcanic islands like the Hawaiian Islands. But most volcanic peaks don't get that high and remain covered by the ocean. There are also probably around 100,000 submarine mountains on the planet, but possibly even more than a million. Currents rich with nutrients move along the slopes of these mountains. A gigantic water vortex forms just above the peak, where many smaller sea animals swirl around. This attracts larger animals from all over the ocean, like schools of tuna or large schools of hammerhead sharks numbering in the hundreds. There's a lot to eat in the vortex. Coldwater corals also grow on the slopes of the mountains, and coral reefs form like they do in the shallow waters of tropical oceans. But coldwater corals don't rely on sunlight. They just eat the plankton in the current, which they catch with tiny polyps on their small tentacles. Sometimes huge jellyfish as large as one meter in diameter can be found around these seamounts. But it's not one of those transparent jellyfish – this one's velvety and red-brown. It doesn't catch its prey with long, thin-nettled threads, but rather with thick, meaty tentacles. Researchers named this unusual, monstrous animal the Big Ugly when it was first discovered a few years ago, but they later renamed the jellyfish the Big Red. Sounds a lot nicer. Who wants to be called the Big Ugly? Not me. The Big Brilliant is more like it. Or the Little Yellow. I think Quentin saw something. There's something over there. And it's huge. Oh, wow. If that's what I think it is, that's one very big fish. Correction. It's a whale. A blue whale. Ballinoptera musculus. So it's a mammal, not a fish. But it's dead. It won't be around for long. I can't believe it. A shark! And long, slimy fish. Hagfish get hungry too. They're eating the whale. But it's kind of fascinating.