Amphibians 102 Chapter 3
Newts and Salamanders
Even more closely related to each other than Frogs to Toads, the Newts and Salamanders are all members of a single family, the Salamandrids, living only in the Northern Hemisphere, in North America, Europe, the very northern tip of Africa and Asia. Newts are considered a more fully aquatic subfamily, while Salamanders, also known as Sirens, Mudpuppies and Olms, are considered more terrestrial, but that’s more of a linguistic distinction than a scientific one. Our North American Newts have a really interesting three-stage life cycle, starting out as a swimming tadpole with feathery gills, then metamorphosing into a completely terrestrial juvenile “eft”, before returning to the water as adults to a completely aquatic adult lifestyle! Newts and Salamanders look similar and share many physical characteristics, including a smooth, wet skin, four limbs and a tail, as well as bright colors that identify them as poisonous to predators the same way that some Amazonian tree frogs do. One species, the Rough Skinned Newt of the Pacific Northwest, has enough of the same deadly poison as is found in the liver of fugu blowfish to kill a man – but only if eaten. Don’t eat them.
By Brian Gratwicke [CC-BY-2.0], via Wikimedia Commons
What’s REALLY cool about them is their ability to regrow body parts. Some Salamanders actually use this as a defense mechanism. When threatened, they can release their tail, which continues to wiggle, drawing the attention of their adversary while the Salamander makes its escape. Even more impressive, some Newts can actually regenerate organs, not just simple stuff like tails or digits. Newts can regrow lost eyes, intestines, spinal cords, even hearts, by turning cells at the site of the injury into generic cells – stem cells – that multiply quickly and then turn into whatever the Newt needs to regrow! Cancer researchers are particularly interested in these abilities, since chemicals that cause cancer in other animals just make Newts regrow limbs.
Newts and Salamanders for the most part do not cause any particular issues in the backyard pond unless eaten by fish or pets. On the other hand, like frogs, they serve as excellent bioindicators of the overall health of the pond, since they cannot survive in ponds with poor water quality. Because their skin is highly permeable to oxygen and other substances, most species are highly sensitive to subtle changes in pH levels and even the tiniest amounts of toxic or foreign substances in the water. If contact with pets or small children is a concern, the easiest way to remove Newts or Salamanders from any ornamental water feature is to add low dosages of pond salt which they cannot tolerate, and they will simply leave the area. Ion Generators may also rid waters of Newts and Salamanders because of the small quantities of metal ions in the water.
Even more closely related to each other than Frogs to Toads, the Newts and Salamanders are all members of a single family, the Salamandrids, living only in the Northern Hemisphere, in North America, Europe, the very northern tip of Africa and Asia. Newts are considered a more fully aquatic subfamily, while Salamanders, also known as Sirens, Mudpuppies and Olms, are considered more terrestrial, but that’s more of a linguistic distinction than a scientific one. Our North American Newts have a really interesting three-stage life cycle, starting out as a swimming tadpole with feathery gills, then metamorphosing into a completely terrestrial juvenile “eft”, before returning to the water as adults to a completely aquatic adult lifestyle! Newts and Salamanders look similar and share many physical characteristics, including a smooth, wet skin, four limbs and a tail, as well as bright colors that identify them as poisonous to predators the same way that some Amazonian tree frogs do. One species, the Rough Skinned Newt of the Pacific Northwest, has enough of the same deadly poison as is found in the liver of fugu blowfish to kill a man – but only if eaten. Don’t eat them.
By Brian Gratwicke [CC-BY-2.0], via Wikimedia Commons
What’s REALLY cool about them is their ability to regrow body parts. Some Salamanders actually use this as a defense mechanism. When threatened, they can release their tail, which continues to wiggle, drawing the attention of their adversary while the Salamander makes its escape. Even more impressive, some Newts can actually regenerate organs, not just simple stuff like tails or digits. Newts can regrow lost eyes, intestines, spinal cords, even hearts, by turning cells at the site of the injury into generic cells – stem cells – that multiply quickly and then turn into whatever the Newt needs to regrow! Cancer researchers are particularly interested in these abilities, since chemicals that cause cancer in other animals just make Newts regrow limbs.
Newts and Salamanders for the most part do not cause any particular issues in the backyard pond unless eaten by fish or pets. On the other hand, like frogs, they serve as excellent bioindicators of the overall health of the pond, since they cannot survive in ponds with poor water quality. Because their skin is highly permeable to oxygen and other substances, most species are highly sensitive to subtle changes in pH levels and even the tiniest amounts of toxic or foreign substances in the water. If contact with pets or small children is a concern, the easiest way to remove Newts or Salamanders from any ornamental water feature is to add low dosages of pond salt which they cannot tolerate, and they will simply leave the area. Ion Generators may also rid waters of Newts and Salamanders because of the small quantities of metal ions in the water.
