 Good morning, John. One of the main thing about fish is the swimming. Being on land can suck because of how stuck you are to it. Like the top performing human in the world right now can get like eight feet off the ground unassisted. And then after all that work, they just come right back down. This doesn't actually sound that bad until you look at it, but like lots of animals have like literally evolved their arms off to be able to swim up into the air. Bugs, bats, birds, flying is extremely useful. It adds a third dimension to the two dimensional world I inhabit. It's easy to forget that air is a fluid until you stick your face onto one of those high performance hand dryers. Water is also a fluid. It's just much more dense. Animals who live there, all of them fly through water. Well, okay, not all of them. John, this is the red hand fish. They can swim, but they almost never do. Instead, when they move, which they rarely do, they walk across the bottom of the ocean on their modified fins that look almost upsettingly hand-like. Hand fish are kind of angler fish, and they live in only one place in the world, south-eastern Australia. And they're not doing great. The red hand fish is arguably the rarest fish on earth. There are only two populations, each with less than 50 adult individuals. So it's not for lack of trying. Hand fish moms vigilantly protect their eggs from potential marauders for weeks on end, never leaving them until they hatch, and every time a clutch of red hand fish eggs hatches, the world population of red hand fish literally doubles. So most fish use these hatching events for what's called dispersal. The little fish are larval forms, and they become like planktonic. They just let the ocean carry them around. Most of them end up in places that aren't going to be great, but some of them end up in places where they can thrive. But no, and this is very weird. Hand fish babies are just hand fish that are smaller. They have no swim bladders, just like adult hand fish. They just sink to the ground because they are very dense, just like adult hand fish. So there are these two isolated pockets where red hand fish are, and all the babies just fall to the ground in the two places where they're left. This is not great for the survival of the species. Indeed, and this kind of blew my mind, the IUCN, which is the organization responsible for this stuff, has classified only one marine fish as officially extinct. That was not meant to be a pun. And this is not to say that there haven't been other marine fish that have gone extinct. This is more a function of not knowing very much about the ocean. The smooth hand fish is known from a single museum specimen that was collected 203 years ago. And after a lot of science and a lot of surveys, it has not been seen since. Will the red hand fish share its fate? Possibly. But the good news is that the Hand Fish Conservation Project is right now raising recently hatched hand fish in captivity, allowing them to introduce new genetic diversity into these two isolated populations and potentially to reintroduce them to new habitats. And as for why these little anglerfish choose to walk instead of fly through their world. This is really important. There is a reason, but we do not know it. We do not know almost everything. We feel like we do, because we have a tremendous bias toward knowing things that are known because of how we cannot know the things that are unknown. Making these Bizarre Beasts videos reminds me that the things we hear about, these amazing astounding facts from the natural world, every one of those isn't something that somebody like picked out of a book. It was something that was discovered or figured out by a person, by people. The most bizarre of beasts. John, I'll see you on Tuesday. Thank you to the wonderful people at the Hand Fish Conservation Project for helping me out with this video and also for all the lovely footage. I love your fish. Thank you for trying to save them. Check out their work at handfish.org.au