Liberal Arts Blog — Herpetology (Part Five): Salamanders (Tennessee, China, Tail Autotomy, Newts, Efts, And Tetrodotoxin)
Liberal Arts Blog — Wednesday is the Joy of Science, Engineering, and Technology Day
Today’s Topic — Herpetology (Part Five): Salamanders (Tennessee, China, tail autotomy, newts, efts, and tetrodotoxin)
Roughly two years, in Part Four of “Herpetology” we covered the miracle of nature called the axolotl — the “Peter Pan of salamanders” (because or its extraordinary regenerative powers). Today, in Part Five, a second look at salamanders generally, Herpetologists you may remember study both reptiles and amphibians. Are you a herpetologist (amateur or professional)? What have you learned in class or out of class that the rest of us might delight to learn?
Experts — please chime in. Correct, elaborate, elucidate.
SALAMANDERS — did you know that Tennessee is the “Salamander State”?
1. The Great Smoky Mountains on the state’s eastern border is known as
“the Salamander Capital of the World” because of its “diversity and abundance of salamander species.”
2. The largest salamander (the hellbender, above) is can reach about 2 feet long.
3. However, the Chinese salamander is much, much larger — up to 6 feet long!
NB: General characteristics: “slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults.”
“Salamanders never have more than four toes on their front legs and five on their rear legs, but some species have fewer digits and others lack hind limbs. Their permeable skin usually makes them reliant on habitats in or near water or other cool, damp places.
Some salamander species are fully aquatic throughout their lives, some take to the water intermittently, and others are entirely terrestrial as adults.”
TAIL AUTOTOMY — self-amputation for survival; but can also regenerate the retina, even the heart
1. Tail autotomy — “the tail drops off and wriggles around for a while after an attack, and the salamander either runs away or stays still enough not to be noticed while the predator is distracted.”
2. “The tail regrows with time, and salamanders routinely regenerate other complex tissues, including the lens or retina of the eye. Within only a few weeks of losing a piece of a limb, a salamander perfectly reforms the missing structure.”
3. “The remarkable ability of salamanders to regenerate is not just limited to limbs but extends to vital organs such as the heart, jaw, and parts of the spinal cord, showing their uniqueness compared to different types of vertebrates. ”
NB: “This ability is most remarkable for occurring without any type of scarring. This has made salamanders an invaluable model organism in scientific research aimed at understanding and achieving regenerative processes for medical advancements in human and animal biology.”
NEWTS ARE A TYPE OF SALAMANDER — and their terrestrial juvenile phase is called an “eft.” (see elow)
1. “Unlike other members of the family Salamandridae newts are semiaquatic, alternating between aquatic and terrestrial habitats. Not all aquatic salamanders are considered newts, however.”
2. “More than 100 known species of newts are found in North America, Europe, North Africa and Asia. Newts metamorphose through three distinct developmental life stages: aquatic larva, terrestrial juvenile (eft), and adult.”
3. “Adult newts have lizard-like bodies and return to the water every year to breed, otherwise living in humid, cover-rich land habitats.”
TETRODOTOXIN (TTX) — blocks sodium channels and causes paralysis — also found in puffer fish, Chemical structure:
1. ”The toxin is produced by symbiotic bacteria living on the newt’s skin and is found in all developmental stages, including eggs and larvae.”
2. “It is more than 1,000 times more potent than cyanide.”
3.”Because TTX is much larger than a sodium ion, it acts like a cork in a bottle and prevents the flow of sodium.”
NB: “Poisoning from tetrodotoxin is of particular public health concern in Japan, where fugu is a traditional delicacy.
It is prepared and sold in special restaurants where trained and licensed chefs carefully remove the viscera to reduce the danger of poisoning.There is potential for misidentification and mislabelling, particularly of prepared, frozen fish products.”
In many films and television shows, “tetrodotoxin serves as a plot device for characters to fake death.”
https://en.wikipedia.org/wiki/Salamander
https://en.wikipedia.org/wiki/Hellbender
https://en.wikipedia.org/wiki/Chinese_giant_salamander
https://en.wikipedia.org/wiki/Newt
https://en.wikipedia.org/wiki/Rough-skinned_newt
https://en.wikipedia.org/wiki/Tennessee_cave_salamander
https://en.wikipedia.org/wiki/Tetrodotoxin
QUOTE OF THE MONTH
“Make your own Bible. Select and collect all the words and sentences that in all your readings have been to you like the blast of a trumpet.”
- Ralph Waldo Emerson
My spin — then periodically review, re-rank, and exchange your list with those you love. I call this the “Orion Exchange” because seven is about as many as any human can digest at a time. Game?
A LINK TO THE LAST FOUR YEARS OF POSTS ORGANIZED BY THEME:
PDF with headlines — Google Drive
ATTACHMENT BELOW:
#1 A graphic guide to justice (9 metaphors on one page).
#2 “39 Songs, Prayers, and Poems: the Keys to the Hearts of Seven Billion People” — Adams House Senior Common Room Presentation, (11/17/20)
NB: Palestine Orion (Decision) — let’s exchange Orions, let’s find Rumi’s field (“Beyond all ideas of right and wrong, there is a field. Meet me there” Rumi, 13 century Persian Sufi mystic)
YOUR TURN
Please share the coolest thing you learned this week related to science, engineering, or technology.
Or, even better, the coolest or most important thing you learned in your life related to science and engineering.
This is your chance to make someone else’s day. Or to cement in your mind something that you might otherwise forget. Or to think more deeply about something dear to your heart. Continuity is key to depth of thought.
