Episode 275: The Axolotl, the Hellbender, and Friends
b"This week it's Zoe and Dillon's episode! They wanted to learn about some really interesting salamanders, including the axolotl and the hellbender!\\n\\nA big birthday shout-out to Heather R. too. The very happiest of birthdays to you!\\n\\nFurther reading:\\n\\nMexico City\\u2019s endangered axolotl has found fame\\u2014is that enough to save it?\\n\\nHow Do Salamanders Breathe?\\n\\nMost wild axolotls are brown:\\n\\n\\n\\nMost captive-bred axolotls are leucistic:\\n\\n\\n\\nThe hellbender doesn't have external gills as an adult:\\n\\n\\n\\nThe red eft, the juvenile stage of the red-spotted newt:\\n\\n\\n\\nAdult mudpuppies have external gills just like axolotls do:\\n\\n\\n\\nShow transcript:\\nWelcome to Strange Animals Podcast. We\\u2019re your cohosts, Zoe and Dillon. And I\\u2019m your third cohost, Kate Shaw.\\nThis week we have Zoe and Dillon\\u2019s episode, and they want to learn about the axolotl, the hellbender, and some other salamanders. It\\u2019ll be the greatest amphibian episode ever!\\nBut 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.\\nSo, let\\u2019s start with the axolotl, because everyone loves it! \\u201cAxolotl\\u201d isn\\u2019t the way it\\u2019s pronounced in its native country of Mexico, since it comes from the name of an Aztec god of fire and lightning, but it\\u2019s the common pronunciation in English so I\\u2019m 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\\u2019t make it onto the suggestions list.\\nWay 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\\u2019t 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.\\nVery 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\\u2019s 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\\u2019s what the axolotl is supposed to do.\\nThe axolotl\\u2019s 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\\u2019s 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\\u2019ve 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.\\nAlso if you\\u2019ve only ever seen pictures of axolotls you may think they\\u2019re all white or pink. That\\u2019s 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.\\nIt\\u2019s captive axolotls that are so often white or pink, or sometimes other colors or patterns. That\\u2019s because they\\u2019re bred for the pet trade and for medical research, because not only are they cute and relatively easy..."