Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff.
Speaker 1: Lauren Vogelbaum. Here today we're talking about axe lottles, a
Speaker 1: threatened species of large salamander that live in fresh water,
Speaker 1: and they're not actually fish at all. Despite sometimes being
Speaker 1: called Mexican walking fish. With their round heads and permanently
Speaker 1: smiling faces, wild axe lottles are cute. It's one of
Speaker 1: the reasons they do well with pet owners in the
Speaker 1: pet trade. One reason they're cute is because they display niatny,
Speaker 1: which means they retain a lot of their juvenile features
Speaker 1: throughout their adult life, beyond their faces. Although adult axe
Speaker 1: lottles also have functional lungs like other salamander species and
Speaker 1: can breathe through their skin, they also have big, fluffy,
Speaker 1: feathery external gills, something most amphibians don't keep after babyhood.
Speaker 1: They have small, delicate, webbed feet and a long tadpole
Speaker 1: like tail crusted with a translucent fin. Because they don't
Speaker 1: have to rely on their webbed feet and legs for
Speaker 1: land travel, but they do have to be able to
Speaker 1: move through water like a big tadpole. In the wild,
Speaker 1: they're most often dark brown, gray or black, with lighter speckles,
Speaker 1: but deepigmented variants with gold skin and eyes or pink
Speaker 1: skin and red gills are common, and you often see
Speaker 1: them as pets as scientists think that they stay baby
Speaker 1: like throughout their lifespans because, unlike other salamondar species, the
Speaker 1: wild ax lottl population evolved in very stable habitats. In
Speaker 1: most other salamonder species, such as the tiger salamander, live
Speaker 1: in wetlands that dry up during certain parts of the year,
Speaker 1: so they have to get rid of their feathery gills
Speaker 1: and breathe through functional lungs and through their skin. A
Speaker 1: wild ax lottles evolved in a habitat with year round
Speaker 1: water and with very few aquatic predators, so they don't
Speaker 1: need to spend energy changing their bodies to suit their
Speaker 1: changing circumstances. An x lottle's life span is about fifteen
Speaker 1: years in captivity, but a wild x lottle probably lives
Speaker 1: only five or six years. They reach sexual maturity at
Speaker 1: one year, and though they are solitary creatures for the
Speaker 1: most part, in February, breeding season begins and wild ax
Speaker 1: lottle males begin finding females using pheromones. When they get together,
Speaker 1: he does a courtship dance in which he shakes his
Speaker 1: tail in her direction. After the female acquiesces to his attentions,
Speaker 1: she pokes him with her nose and he deposits a
Speaker 1: sperm packet on the lake floor, which he picks up
Speaker 1: and uses to fertilize her eggs. The wild, female ex
Speaker 1: lottle will lay hundreds of eggs in the weeds or
Speaker 1: around some rocks, and then leave them to fen for themselves.
Speaker 1: Baby x lottles receive zero parental care. In fact, young
Speaker 1: axe lottels, hungry after hatching from their eggs, have been
Speaker 1: observed gnawing on their siblings legs and pails for sustenance,
Speaker 1: though as you'll see, this is totally fine because the
Speaker 1: legs will just grow back in their home ecosystem. Axe
Speaker 1: lottles are or at least used to be top predators
Speaker 1: around the lakes, wetlands, and canals of Central Mexico, where
Speaker 1: they originated and once thrived. Although they appear unassuming, they're
Speaker 1: actually ruthless carnivores, feasting on worms, mollusks, insects and insect larvae,
Speaker 1: and even small fish. In the wild, they'll also eat
Speaker 1: pretty much any animal that you put in a tank
Speaker 1: with them. Post ancient Mesoamerican cultures used the axe lottle
Speaker 1: as a source of food and medicine, Some said a
Speaker 1: gift from the gods. A Myths from that area associate
Speaker 1: the animal with an underworld god, Sholat, who in some
Speaker 1: legends escapes capture by turning himself into a small, feathery amphibian.
Speaker 1: His name comes from the Nawat language and is spelled
Speaker 1: the same as axe lottle without the letter A at
Speaker 1: the front, but European language speakers didn't pick up the
Speaker 1: pronunciation when they picked up the animal. A part of
Speaker 1: the mythology of the axe lottl centers around the fact that,
Speaker 1: alike a powerful god, they are difficult to kill. If
Speaker 1: an ox lottl loses virtually any part of its body,
Speaker 1: it can regenerate it no problem a. While sub lizards
Speaker 1: can grow back a tail bisected, flatworms can grow back
Speaker 1: the other half, and starfish can regrow a limb, an
Speaker 1: ax lottle can regrow practically any part of its body
Speaker 1: in a few weeks. For the article this episode is
Speaker 1: based on How Stuff Works. Spoke with David Gardner, a
Speaker 1: professor in the school of Biological Sciences at the University
Speaker 1: of California, Irvine. Back in twenty nineteen, he said, of
Speaker 1: the animals that are closest to us the vertebrates, salamanders
Speaker 1: are the only ones that can regenerate in this way
Speaker 1: and can heal without scars. Other salamanders can regenerate, but
Speaker 1: axe lottls do it best. When the Europeans got wind
Speaker 1: of axe lottal regeneration, ax lottls went from being a
Speaker 1: sort of boring exhibit in a zoo to one of
Speaker 1: the most important and longest self sustaining lab animals in history.
Speaker 1: Among the first modern zoo animals, thirty four ax lottls
Speaker 1: are brought from Mexico, along with three deer and three
Speaker 1: wild dogs, to Paris in eighteen sixty four, and although
Speaker 1: they weren't as interesting to nineteenth century zoogoers as the larger,
Speaker 1: more charismatic animals, scientists quickly realized that these unassuming little
Speaker 1: guys were strange, almost mythological in fact, and they were
Speaker 1: studied at the time for their unusual adult form and
Speaker 1: their regenerative abilities. A Gardner said, these days, ax lottls
Speaker 1: are hugely important model systems for our studies about regeneration.
Speaker 1: We've known for decades, centuries even that we can remove
Speaker 1: parts of a developing embryonic structure and the cells that
Speaker 1: are left behind will fill in, repair and regenerate that structure.
Speaker 1: But in most animals mammals, for instance, the system sort
Speaker 1: of shuts down at the end of embryonic development. Axe
Speaker 1: Lottels and other salamanders seem to be able to revert
Speaker 1: back to that embryonic like state, reaccessing the developmental program
Speaker 1: that's already there. Humans have the program, we just stop
Speaker 1: being able to access it when we're no longer an embryo.
Speaker 1: You could say, we, like axe lottels, have evolved the
Speaker 1: ability to regenerate just fine, but we've also evolved a
Speaker 1: mechanism that inhibits that. Scientists hope to figure out how
Speaker 1: to one day apply the axe lottl's regeneration abilities to
Speaker 1: the human body. They can regenerate new limbs, heart tissue, eyes,
Speaker 1: and even its spinal cord in parts of their brain,
Speaker 1: and make new neurons throughout their lives, which human brains
Speaker 1: do too, though not as readily. It is possible to
Speaker 1: force anax lottel to metamorphin into an adult salamander without
Speaker 1: gills by injecting it with iodine or thyroxine, or by
Speaker 1: feeding it foods that are rich in iodine. However, scientists
Speaker 1: have found that afterward they don't easily regenerate cells, and
Speaker 1: for all their seeming magic, wild ax lottls are critically
Speaker 1: endangered today. The waterways in their home around Mexico City
Speaker 1: have become not only polluted by aging wastewater systems, but
Speaker 1: overrun by introduced telapia and perch, both of which view
Speaker 1: ax lottles as a delicious snack. In twenty nineteen, a
Speaker 1: population assessment concluded that there are probably fewer than one
Speaker 1: thousand individuals left in the wild. The Mexican government and
Speaker 1: many conservation groups are doing their best to save the
Speaker 1: species by restoring the lakes and natural habitats they live in.
Speaker 1: One strategy is to make stationary floating island habitats for them,
Speaker 1: called danumpas a Spanish word for rafts made of aquatic vegetation, mud,
Speaker 1: and wood that were used hundreds of years ago as
Speaker 1: floating gardens before Spanish colonizers arrived. When what's now part
Speaker 1: of Mexico City was the Triple Alliance City, state of
Speaker 1: tinoche Titlan. The Empire built and farmed on a vast
Speaker 1: network of chanampas for miles around the city. This system
Speaker 1: of agriculture created canals that were shallow and sheltered, and
Speaker 1: where the ox lottl popular thrived. When the Spanish conquered
Speaker 1: the city, they remove the chumpus and drained the canals
Speaker 1: and lakes. Today, the natural habitat of the wild oxilotl
Speaker 1: population is limited to the southern part of Mexico City.
Speaker 1: People are working to remove the invasive fishes that eat
Speaker 1: the axe lottls and begin using jenumpus again, which not
Speaker 1: only provides habitat for the axe lottles, it also filters
Speaker 1: toxins out of the lake water. Ecotourism of these danumpus
Speaker 1: has assisted in funding axe loottal conservation efforts. Meanwhile, captive
Speaker 1: populations axe lottls are doing great. They're the most widely
Speaker 1: distributed amphibian in the world, and because scientists desperately want
Speaker 1: to figure out how to help you regenerate a new
Speaker 1: set of toes, millions of them live in labs around
Speaker 1: the globe. And while axe lottle research is important in
Speaker 1: science and captive populations of pet axe lottls are also popular.
Speaker 1: It's not legal everywhere for pet owners to keep ax lottles,
Speaker 1: so it's important to check your local exotic pet laws
Speaker 1: before you go looking for one and mess with any
Speaker 1: living creature. Be sure to read up on how to
Speaker 1: care for one before you take the dive. No pun intended.
Speaker 1: They're not difficult to keep per se, but speaking as
Speaker 1: a home aquarium enthusiast myself, I can tell you that
Speaker 1: keeping any aquatic life form comfortable in your non aquatic
Speaker 1: home can take a lot of work. Today's episode is
Speaker 1: based on the article the super cute axe Lottle is
Speaker 1: also a ruthless carnivore on HowStuffWorks dot Com, written by Jesslinshields.
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Speaker 1: stuffworks dot Com and is produced by Tyler Klang. Perform
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