This week it's Zoe and Dillon's episode! They wanted to learn about some really interesting salamanders, including the axolotl and the hellbender! A big birthday shout-out to Heather R. too. The very happiest of birthdays to you! Further reading: Mexico City’s endangered axolotl has found fame—is that enough to save it? How Do Salamanders Breathe? Most wild axolotls are brown: Most captive-bred axolotls are leucistic: The hellbender doesn't have external gills as an adult: The red eft, the juvenile stage of the red-spotted newt: Adult mudpuppies have external gills just like axolotls do: Show transcript: Welcome to Strange Animals Podcast. We’re your cohosts, Zoe and Dillon. And I’m your third cohost, Kate Shaw. This week we have Zoe and Dillon’s episode, and they want to learn about the axolotl, the hellbender, and some other salamanders. It’ll be the greatest amphibian episode ever! But first, we have a birthday shout-out! Happy birthday to Heather R.! I hope the weather is perfect for your birthday and you get to go out and appreciate it. So, let’s start with the axolotl, because everyone loves it! “Axolotl” isn’t the way it’s pronounced in its native country of Mexico, since it comes from the name of an Aztec god of fire and lightning, but it’s the common pronunciation in English so I’m going to stick with that one. In addition to Zoe and Dillon, at least one other listener has suggested we cover the axolotl. That would be Rosy, and I apologize to anyone else who suggested it but whose name didn’t make it onto the suggestions list. Way back in episode 104, about tiger salamanders, we learned that the tiger salamander is closely related to the axolotl. But the two species look very different most of the time because the axolotl exhibits a trait called neoteny. In most salamanders, the egg hatches into a larval salamander that lives in water, which means it has external gills so it can breathe underwater. It grows and ultimately metamorphoses into a juvenile salamander that spends most of its time on land, so it loses its external gills in the metamorphosis. Eventually it takes on its adult coloration and pattern. But the axolotl doesn’t metamorphose. Even when it matures, it still looks kind of like a big larva, complete with external gills, and it lives underwater its whole life. Very rarely, an axolotl metamorphoses into an adult form, at which point it looks a whole lot like a tiger salamander. This generally happens if the individual is exposed to excess iodine in its diet, and metamorphosing like this may actually lead to the axolotl’s death. Axolotls exhibit neoteny because it gives them an advantage in their natural range, so even though it seems strange to us compared to all those other salamanders, it’s what the axolotl is supposed to do. The axolotl’s natural range is very specific. Originally it lived in two large, cold lakes in the Valley of Mexico. This is where Mexico City is and it’s been a hub of civilization for thousands of years. A million people lived there in 1521 when the Spanish invaded and destroyed the Aztec Empire with introduced diseases and war. The axolotl was an important food of the Aztecs and the civilizations that preceded them, and if you’ve only ever seen pictures of axolotls you may wonder why. Salamanders are usually small, but a full-grown axolotl can grow up to 18 inches long, or 45 cm, although most are about half that length. Also if you’ve only ever seen pictures of axolotls you may think they’re all white or pink. That’s actually rare in the wild. Most wild axolotls are brown, greenish-brown, or gray, often with lighter speckles. They can even change color somewhat to blend in with their surroundings better. It’s captive axolotls that are so often white or pink, or sometimes other colors or patterns. That’s because they’re bred for the pet trade and for medical research, because not only are they cute and relatively easy...