WEBVTT - How Do Axolotls Work?

0:00:01.840 --> 0:00:07.520
<v Speaker 1>Welcome to Brainstuff, a production of iHeartRadio. Hey brain Stuff.

0:00:07.600 --> 0:00:12.440
<v Speaker 1>Lauren Vogelbaum. Here today we're talking about axe lottles, a

0:00:12.560 --> 0:00:15.760
<v Speaker 1>threatened species of large salamander that live in fresh water,

0:00:16.200 --> 0:00:19.400
<v Speaker 1>and they're not actually fish at all. Despite sometimes being

0:00:19.440 --> 0:00:23.680
<v Speaker 1>called Mexican walking fish. With their round heads and permanently

0:00:23.680 --> 0:00:27.600
<v Speaker 1>smiling faces, wild axe lottles are cute. It's one of

0:00:27.640 --> 0:00:29.479
<v Speaker 1>the reasons they do well with pet owners in the

0:00:29.480 --> 0:00:33.840
<v Speaker 1>pet trade. One reason they're cute is because they display niatny,

0:00:34.200 --> 0:00:36.760
<v Speaker 1>which means they retain a lot of their juvenile features

0:00:36.800 --> 0:00:42.200
<v Speaker 1>throughout their adult life, beyond their faces. Although adult axe

0:00:42.200 --> 0:00:45.920
<v Speaker 1>lottles also have functional lungs like other salamander species and

0:00:46.120 --> 0:00:49.599
<v Speaker 1>can breathe through their skin, they also have big, fluffy,

0:00:49.800 --> 0:00:54.920
<v Speaker 1>feathery external gills, something most amphibians don't keep after babyhood.

0:00:56.040 --> 0:00:59.280
<v Speaker 1>They have small, delicate, webbed feet and a long tadpole

0:00:59.360 --> 0:01:02.720
<v Speaker 1>like tail crusted with a translucent fin. Because they don't

0:01:02.760 --> 0:01:04.520
<v Speaker 1>have to rely on their webbed feet and legs for

0:01:04.600 --> 0:01:07.040
<v Speaker 1>land travel, but they do have to be able to

0:01:07.080 --> 0:01:10.679
<v Speaker 1>move through water like a big tadpole. In the wild,

0:01:10.720 --> 0:01:14.000
<v Speaker 1>they're most often dark brown, gray or black, with lighter speckles,

0:01:14.440 --> 0:01:17.960
<v Speaker 1>but deepigmented variants with gold skin and eyes or pink

0:01:17.959 --> 0:01:20.600
<v Speaker 1>skin and red gills are common, and you often see

0:01:20.600 --> 0:01:25.000
<v Speaker 1>them as pets as scientists think that they stay baby

0:01:25.120 --> 0:01:28.920
<v Speaker 1>like throughout their lifespans because, unlike other salamondar species, the

0:01:28.920 --> 0:01:33.679
<v Speaker 1>wild ax lottl population evolved in very stable habitats. In

0:01:33.760 --> 0:01:37.400
<v Speaker 1>most other salamonder species, such as the tiger salamander, live

0:01:37.440 --> 0:01:40.199
<v Speaker 1>in wetlands that dry up during certain parts of the year,

0:01:40.800 --> 0:01:43.000
<v Speaker 1>so they have to get rid of their feathery gills

0:01:43.080 --> 0:01:46.600
<v Speaker 1>and breathe through functional lungs and through their skin. A

0:01:46.680 --> 0:01:49.520
<v Speaker 1>wild ax lottles evolved in a habitat with year round

0:01:49.560 --> 0:01:53.000
<v Speaker 1>water and with very few aquatic predators, so they don't

0:01:53.000 --> 0:01:55.800
<v Speaker 1>need to spend energy changing their bodies to suit their

0:01:55.920 --> 0:02:01.080
<v Speaker 1>changing circumstances. An x lottle's life span is about fifteen

0:02:01.160 --> 0:02:04.120
<v Speaker 1>years in captivity, but a wild x lottle probably lives

0:02:04.120 --> 0:02:07.360
<v Speaker 1>only five or six years. They reach sexual maturity at

0:02:07.400 --> 0:02:10.080
<v Speaker 1>one year, and though they are solitary creatures for the

0:02:10.080 --> 0:02:13.839
<v Speaker 1>most part, in February, breeding season begins and wild ax

0:02:13.880 --> 0:02:18.280
<v Speaker 1>lottle males begin finding females using pheromones. When they get together,

0:02:18.480 --> 0:02:20.639
<v Speaker 1>he does a courtship dance in which he shakes his

0:02:20.720 --> 0:02:24.559
<v Speaker 1>tail in her direction. After the female acquiesces to his attentions,

0:02:24.680 --> 0:02:27.040
<v Speaker 1>she pokes him with her nose and he deposits a

0:02:27.080 --> 0:02:29.560
<v Speaker 1>sperm packet on the lake floor, which he picks up

0:02:29.600 --> 0:02:33.799
<v Speaker 1>and uses to fertilize her eggs. The wild, female ex

0:02:33.880 --> 0:02:36.240
<v Speaker 1>lottle will lay hundreds of eggs in the weeds or

0:02:36.400 --> 0:02:39.440
<v Speaker 1>around some rocks, and then leave them to fen for themselves.

0:02:39.960 --> 0:02:44.160
<v Speaker 1>Baby x lottles receive zero parental care. In fact, young

0:02:44.160 --> 0:02:47.280
<v Speaker 1>axe lottels, hungry after hatching from their eggs, have been

0:02:47.280 --> 0:02:50.280
<v Speaker 1>observed gnawing on their siblings legs and pails for sustenance,

0:02:51.240 --> 0:02:53.959
<v Speaker 1>though as you'll see, this is totally fine because the

0:02:54.040 --> 0:02:59.480
<v Speaker 1>legs will just grow back in their home ecosystem. Axe

0:02:59.520 --> 0:03:02.520
<v Speaker 1>lottles are or at least used to be top predators

0:03:02.600 --> 0:03:06.000
<v Speaker 1>around the lakes, wetlands, and canals of Central Mexico, where

0:03:06.000 --> 0:03:10.720
<v Speaker 1>they originated and once thrived. Although they appear unassuming, they're

0:03:10.800 --> 0:03:16.240
<v Speaker 1>actually ruthless carnivores, feasting on worms, mollusks, insects and insect larvae,

0:03:16.400 --> 0:03:19.440
<v Speaker 1>and even small fish. In the wild, they'll also eat

0:03:19.520 --> 0:03:21.400
<v Speaker 1>pretty much any animal that you put in a tank

0:03:21.440 --> 0:03:26.240
<v Speaker 1>with them. Post ancient Mesoamerican cultures used the axe lottle

0:03:26.320 --> 0:03:29.320
<v Speaker 1>as a source of food and medicine, Some said a

0:03:29.360 --> 0:03:32.799
<v Speaker 1>gift from the gods. A Myths from that area associate

0:03:32.840 --> 0:03:36.040
<v Speaker 1>the animal with an underworld god, Sholat, who in some

0:03:36.200 --> 0:03:40.240
<v Speaker 1>legends escapes capture by turning himself into a small, feathery amphibian.

0:03:41.320 --> 0:03:44.160
<v Speaker 1>His name comes from the Nawat language and is spelled

0:03:44.160 --> 0:03:46.320
<v Speaker 1>the same as axe lottle without the letter A at

0:03:46.320 --> 0:03:49.480
<v Speaker 1>the front, but European language speakers didn't pick up the

0:03:49.480 --> 0:03:53.840
<v Speaker 1>pronunciation when they picked up the animal. A part of

0:03:53.840 --> 0:03:56.600
<v Speaker 1>the mythology of the axe lottl centers around the fact that,

0:03:56.800 --> 0:04:00.720
<v Speaker 1>alike a powerful god, they are difficult to kill. If

0:04:00.720 --> 0:04:03.560
<v Speaker 1>an ox lottl loses virtually any part of its body,

0:04:03.600 --> 0:04:07.520
<v Speaker 1>it can regenerate it no problem a. While sub lizards

0:04:07.560 --> 0:04:11.240
<v Speaker 1>can grow back a tail bisected, flatworms can grow back

0:04:11.280 --> 0:04:14.400
<v Speaker 1>the other half, and starfish can regrow a limb, an

0:04:14.440 --> 0:04:17.400
<v Speaker 1>ax lottle can regrow practically any part of its body

0:04:17.480 --> 0:04:21.080
<v Speaker 1>in a few weeks. For the article this episode is

0:04:21.120 --> 0:04:23.719
<v Speaker 1>based on How Stuff Works. Spoke with David Gardner, a

0:04:23.760 --> 0:04:26.520
<v Speaker 1>professor in the school of Biological Sciences at the University

0:04:26.520 --> 0:04:30.920
<v Speaker 1>of California, Irvine. Back in twenty nineteen, he said, of

0:04:30.960 --> 0:04:34.320
<v Speaker 1>the animals that are closest to us the vertebrates, salamanders

0:04:34.360 --> 0:04:36.760
<v Speaker 1>are the only ones that can regenerate in this way

0:04:37.080 --> 0:04:41.120
<v Speaker 1>and can heal without scars. Other salamanders can regenerate, but

0:04:41.240 --> 0:04:46.360
<v Speaker 1>axe lottls do it best. When the Europeans got wind

0:04:46.400 --> 0:04:49.480
<v Speaker 1>of axe lottal regeneration, ax lottls went from being a

0:04:49.640 --> 0:04:52.000
<v Speaker 1>sort of boring exhibit in a zoo to one of

0:04:52.000 --> 0:04:55.640
<v Speaker 1>the most important and longest self sustaining lab animals in history.

0:04:56.800 --> 0:04:59.839
<v Speaker 1>Among the first modern zoo animals, thirty four ax lottls

0:05:00.040 --> 0:05:02.520
<v Speaker 1>are brought from Mexico, along with three deer and three

0:05:02.520 --> 0:05:06.680
<v Speaker 1>wild dogs, to Paris in eighteen sixty four, and although

0:05:06.680 --> 0:05:10.440
<v Speaker 1>they weren't as interesting to nineteenth century zoogoers as the larger,

0:05:10.560 --> 0:05:15.320
<v Speaker 1>more charismatic animals, scientists quickly realized that these unassuming little

0:05:15.320 --> 0:05:19.600
<v Speaker 1>guys were strange, almost mythological in fact, and they were

0:05:19.600 --> 0:05:22.400
<v Speaker 1>studied at the time for their unusual adult form and

0:05:22.440 --> 0:05:27.880
<v Speaker 1>their regenerative abilities. A Gardner said, these days, ax lottls

0:05:27.920 --> 0:05:31.280
<v Speaker 1>are hugely important model systems for our studies about regeneration.

0:05:32.080 --> 0:05:35.480
<v Speaker 1>We've known for decades, centuries even that we can remove

0:05:35.520 --> 0:05:38.280
<v Speaker 1>parts of a developing embryonic structure and the cells that

0:05:38.320 --> 0:05:41.919
<v Speaker 1>are left behind will fill in, repair and regenerate that structure.

0:05:42.960 --> 0:05:46.080
<v Speaker 1>But in most animals mammals, for instance, the system sort

0:05:46.080 --> 0:05:49.440
<v Speaker 1>of shuts down at the end of embryonic development. Axe

0:05:49.520 --> 0:05:52.160
<v Speaker 1>Lottels and other salamanders seem to be able to revert

0:05:52.200 --> 0:05:56.400
<v Speaker 1>back to that embryonic like state, reaccessing the developmental program

0:05:56.440 --> 0:06:00.560
<v Speaker 1>that's already there. Humans have the program, we just stop

0:06:00.640 --> 0:06:03.279
<v Speaker 1>being able to access it when we're no longer an embryo.

0:06:04.400 --> 0:06:07.320
<v Speaker 1>You could say, we, like axe lottels, have evolved the

0:06:07.360 --> 0:06:10.760
<v Speaker 1>ability to regenerate just fine, but we've also evolved a

0:06:10.800 --> 0:06:16.840
<v Speaker 1>mechanism that inhibits that. Scientists hope to figure out how

0:06:16.839 --> 0:06:19.839
<v Speaker 1>to one day apply the axe lottl's regeneration abilities to

0:06:19.880 --> 0:06:24.320
<v Speaker 1>the human body. They can regenerate new limbs, heart tissue, eyes,

0:06:24.360 --> 0:06:26.679
<v Speaker 1>and even its spinal cord in parts of their brain,

0:06:27.160 --> 0:06:30.400
<v Speaker 1>and make new neurons throughout their lives, which human brains

0:06:30.440 --> 0:06:35.039
<v Speaker 1>do too, though not as readily. It is possible to

0:06:35.120 --> 0:06:38.960
<v Speaker 1>force anax lottel to metamorphin into an adult salamander without

0:06:39.000 --> 0:06:42.720
<v Speaker 1>gills by injecting it with iodine or thyroxine, or by

0:06:42.760 --> 0:06:46.440
<v Speaker 1>feeding it foods that are rich in iodine. However, scientists

0:06:46.440 --> 0:06:52.400
<v Speaker 1>have found that afterward they don't easily regenerate cells, and

0:06:52.720 --> 0:06:55.880
<v Speaker 1>for all their seeming magic, wild ax lottls are critically

0:06:55.960 --> 0:06:59.760
<v Speaker 1>endangered today. The waterways in their home around Mexico City

0:06:59.839 --> 0:07:03.560
<v Speaker 1>have become not only polluted by aging wastewater systems, but

0:07:03.760 --> 0:07:07.520
<v Speaker 1>overrun by introduced telapia and perch, both of which view

0:07:07.560 --> 0:07:11.440
<v Speaker 1>ax lottles as a delicious snack. In twenty nineteen, a

0:07:11.520 --> 0:07:14.600
<v Speaker 1>population assessment concluded that there are probably fewer than one

0:07:14.640 --> 0:07:19.760
<v Speaker 1>thousand individuals left in the wild. The Mexican government and

0:07:19.880 --> 0:07:22.440
<v Speaker 1>many conservation groups are doing their best to save the

0:07:22.480 --> 0:07:25.640
<v Speaker 1>species by restoring the lakes and natural habitats they live in.

0:07:26.800 --> 0:07:30.480
<v Speaker 1>One strategy is to make stationary floating island habitats for them,

0:07:30.840 --> 0:07:35.679
<v Speaker 1>called danumpas a Spanish word for rafts made of aquatic vegetation, mud,

0:07:35.720 --> 0:07:38.360
<v Speaker 1>and wood that were used hundreds of years ago as

0:07:38.400 --> 0:07:43.920
<v Speaker 1>floating gardens before Spanish colonizers arrived. When what's now part

0:07:43.920 --> 0:07:46.840
<v Speaker 1>of Mexico City was the Triple Alliance City, state of

0:07:46.920 --> 0:07:50.760
<v Speaker 1>tinoche Titlan. The Empire built and farmed on a vast

0:07:50.760 --> 0:07:54.880
<v Speaker 1>network of chanampas for miles around the city. This system

0:07:54.920 --> 0:07:58.720
<v Speaker 1>of agriculture created canals that were shallow and sheltered, and

0:07:58.800 --> 0:08:02.800
<v Speaker 1>where the ox lottl popular thrived. When the Spanish conquered

0:08:02.840 --> 0:08:05.880
<v Speaker 1>the city, they remove the chumpus and drained the canals

0:08:05.880 --> 0:08:11.120
<v Speaker 1>and lakes. Today, the natural habitat of the wild oxilotl

0:08:11.120 --> 0:08:14.160
<v Speaker 1>population is limited to the southern part of Mexico City.

0:08:15.080 --> 0:08:17.920
<v Speaker 1>People are working to remove the invasive fishes that eat

0:08:17.920 --> 0:08:21.400
<v Speaker 1>the axe lottls and begin using jenumpus again, which not

0:08:21.440 --> 0:08:24.720
<v Speaker 1>only provides habitat for the axe lottles, it also filters

0:08:24.760 --> 0:08:29.080
<v Speaker 1>toxins out of the lake water. Ecotourism of these danumpus

0:08:29.200 --> 0:08:35.079
<v Speaker 1>has assisted in funding axe loottal conservation efforts. Meanwhile, captive

0:08:35.080 --> 0:08:38.760
<v Speaker 1>populations axe lottls are doing great. They're the most widely

0:08:38.800 --> 0:08:43.480
<v Speaker 1>distributed amphibian in the world, and because scientists desperately want

0:08:43.520 --> 0:08:45.439
<v Speaker 1>to figure out how to help you regenerate a new

0:08:45.480 --> 0:08:48.240
<v Speaker 1>set of toes, millions of them live in labs around

0:08:48.240 --> 0:08:52.080
<v Speaker 1>the globe. And while axe lottle research is important in

0:08:52.160 --> 0:08:56.080
<v Speaker 1>science and captive populations of pet axe lottls are also popular.

0:08:58.440 --> 0:09:01.760
<v Speaker 1>It's not legal everywhere for pet owners to keep ax lottles,

0:09:02.000 --> 0:09:04.480
<v Speaker 1>so it's important to check your local exotic pet laws

0:09:04.520 --> 0:09:07.880
<v Speaker 1>before you go looking for one and mess with any

0:09:07.920 --> 0:09:10.080
<v Speaker 1>living creature. Be sure to read up on how to

0:09:10.120 --> 0:09:13.120
<v Speaker 1>care for one before you take the dive. No pun intended.

0:09:13.640 --> 0:09:16.920
<v Speaker 1>They're not difficult to keep per se, but speaking as

0:09:17.000 --> 0:09:20.360
<v Speaker 1>a home aquarium enthusiast myself, I can tell you that

0:09:20.480 --> 0:09:23.880
<v Speaker 1>keeping any aquatic life form comfortable in your non aquatic

0:09:23.880 --> 0:09:31.800
<v Speaker 1>home can take a lot of work. Today's episode is

0:09:31.840 --> 0:09:34.199
<v Speaker 1>based on the article the super cute axe Lottle is

0:09:34.240 --> 0:09:38.160
<v Speaker 1>also a ruthless carnivore on HowStuffWorks dot Com, written by Jesslinshields.

0:09:38.600 --> 0:09:41.160
<v Speaker 1>Brain Stuff is production of iHeartRadio in partnership with how

0:09:41.160 --> 0:09:44.320
<v Speaker 1>stuffworks dot Com and is produced by Tyler Klang. Perform

0:09:44.320 --> 0:09:47.160
<v Speaker 1>more podcasts from my heart Radio, visit the iHeartRadio app,

0:09:47.280 --> 0:10:00.920
<v Speaker 1>Apple Podcasts, or wherever you listen to your favorite shows.