Good morning, John.

One of the main  things about fish is the swimming. Welcome back!

This is the second episode of  Bizarre

Beasts: Season Zero, our year-long project to remaster the original Bizarre Beasts  videos which I made for Vlogbrothers with corrections, updates, and new material. Make sure you stick around for the pin set announcement and for even more bonus  facts about these amazingly weird fish. 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.

There’s a fair amount of conversation  at Bizarre Beasts headquarters about whether a high jump counts as jumping high.   The current world record for highest unassisted jump when you’re just jumping  straight up and you, like, get to a thing,   is 1.7 meters or 5 feet, 7 inches. That was set on February 7, 2021, almost a year after I made this video. But as far as a high jump, which  is a different thing where you jump over a bar,   the record for that was set by Javier  Sotomayor in 1993, and it was about 8 feet.

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   under 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. [♪♪INTRO♪♪] This is the red handfish. 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.

Handfish are a kind of anglerfish and  they live in only one place in the world:   Southeastern Australia, and  they're not doing great. The red handfish is arguably the rarest fish  on Earth. There are only two populations,  each with less than 50 adult individuals.

Though it's not for lack of trying. Handfish 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 handfish eggs hatches, the world population of red handfish literally doubles. So, to be more specific here, the adult  handfish guards the eggs for 7 to 8 weeks   in late spring when they spawn.

And each egg mass contains around 30 to 60 eggs. 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 gonna be great,   but some of them end up in places  where they can thrive, but no,   and this is very weird, handfish babies  are just handfish that are smaller. They have no swim bladders, just  like adult handfish.

They just  sink to the ground because they are  very dense, just like adult handfish. So there are these two isolated pockets  where red handfish 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. But the smooth handfish 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.

I actually have an update about the smooth  handfish to share here! After I originally  made this video, the IUCN reversed their  decision about the smooth handfish. It’s  not listed as extinct anymore - now,  it’s considered ‘data deficient.’ And  that just means the IUCN doesn’t think  there’s enough information to assess   its risk of extinction based on its  distribution or population status.

What made them change their minds came down to  how they define ‘extinct.’ Their definition is, quote:  “A taxon is Extinct when there is no reasonable  doubt that the last individual has died. A taxon is presumed Extinct when exhaustive surveys in  known and/or expected habitat, at appropriate  times…, [and] throughout its historic range  have failed to record an individual. Surveys  should be over a time frame appropriate  to the taxon’s life cycle and life form.” And the petition to un-classify the  smooth handfish was based on what counts   as an “exhaustive survey” in the  definition of extinction.

Essentially,  neither side provided a good enough quantification  of whether surveys for the smooth handfish have  been exhaustive enough, so the IUCN concluded  there wasn’t enough data to call it extinct. Will the red handfish share its fate?  Possibly, but the good news is that  the Handfish Conservation Project is right now  raising recently hatched handfish 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, buy people, the most bizarre of beasts.

Thanks for watching and thank you again to the Handfish Conservation Project for all of their incredible handfish footage. Thank you for revisiting this beast with me!  If you missed the handfish pin the first time around, our Season Zero pin set is now  available! This set includes all 12 of  the animals that we began this Bizarre Beasts journey with on Vlogbrothers,   as well as a bonus pin for our very first  Bizarre

Beast: the Mola Mola. Mola Mola, we’re  sorry we kept you pin-less for so long!  You are one of the best fish. Hopefully, we’re making it up to you. To get the Season Zero Pin set and everything  else Bizarre Beasts, visit bizarrebeastsshow.com!

So, back at the beginning of the video,  I said handfish are a type of anglerfish. And I know when I think of anglerfish,  I picture the scary-looking,   deep sea-dwelling kind that lures their prey to its  mouth with its built-in light-up fishing pole. But the anglerfish order also includes fish  that don’t live in the lightless depths of the deep ocean,    like the frogfishes, which  can be all kinds of wild colors and patterns.

Handfish are not the only fish  that use their fins to walk! Along with their relatives, the frogfishes  and batfishes, some of the other fish that ‘walk’ in various ways are: the epaulette sharks; walking catfish; and mudskippers! [♪♪OUTRO♪♪]