meet the little guys who can live for a century!

For this Population Action Project, I explored the mysterious Olm to understand its evolution, apply my knowledge of concepts like standard deviation, and hypothesize how this organism would adapt to a new environment. The Olm still puzzles scientists due to its unique adaptations, most notably its ability to live up to around 100 years! How is it possible for the small species of salamander to survive long enough to outlive most people? Further, how are we impacting the Olms’ small population, and what does conservation look like?

(“Proteus Anguinus,” Sebastian Voitel)

(“Proteus Anguinus,” Sebastian Voitel)

Evolution:

• The scientific name for Olms is Proteus Anguinus (Fearnley, 2016).

• The origin of Olms is not entirely clear, but they live primarily in southeastern Europe, within the deep, underwater, limestone caves of the Dinaric Alps. This mountain range crosses through “parts of Slovenia, Italy, Croatia, and Herzegovina,” (JustFunFacts, 2019). It is estimated that this species of salamander has lived safely in the caves for “over 20 million years,” (Yong, 2010). However, Olms separated from other amphibians and salamanders about 110 million years ago! It was around this time (the Cretaceous period) that modern birds also appeared (EDGE). The first written record of the Olm (1969) says that they were washed out of their caves by rain, and people thought they were baby dragons (Fearnley, 2016). 

• It is hypothesized that the previously land dwelling Olms migrated underground due to “tectonic activity” and “dramatic climate shifts,” (Jewett). The dark brown/black Olms dwell closer to the surface, and are a distinct subspecies (Proteus anguinus parkelj). The darker colors show that Olms are not “albinistic,” and have the ability to produce melanin (Science Blogs, 2008). The white olms adapted to their dark environment and rely on their sense of smell and hearing, as well as the ability to sense movements and electricity. 

• Ancestors:*

• *(It is difficult to trace the evolutionary history/ancestors of Olms, so I decided to include their dark subspecies to display the possibility of “convergent evolution,” opposed to showing the differences between Olms and members of the Necturus genus (ScienceBlogs, 2008). 

• Olms are under the family Proteidae, which is separated in two genera: Proteus and Necturus (Salamanderland). Olms are the only species that fall under Proteus, while the North American genus, Necturus, includes five species. 

• This family lies in the suborder Salamandroidea, and there is still controversy about grouping the two genera. It is not clear if Proteus shares a common ancestor like Necturus, Ambystomatidae, Dicamptodontidae and Salamandridae.

• It is likely that the dark olms are both ancestors and a subspecies of Proteus Anguinus (white Olms). This is because Olms may have begun as surface dwelling salamanders, and had to adapt to the underwater caves. Dark olms are not extinct, but survive better near the surface because they have much better eyesight, whereas white Olms don’t rely on eyesight in the depths. 

(“Proteus anguinus parkelj,” Sebastian Voitel)

Guiding Questions:

• What environments do Olms thrive in?

• Olms can be found in the dark, underwater caves of the Dinaric Alps (southeastern Europe). They thrive in these environments because they have poor eyesight and rely on their other senses to catch prey and navigate the cave systems (JustFunFacts).

• What adaptations allow them to flourish, or put them at risk?

• Lateral lines: assist in their hearing and sensitivity to “water displacement.”

• Electro receptors: Sensory organs in the Olms’ head allows them to recognize different magnetic and electrical fields. 

• Diet: Olms can go nearly a decade without eating, and are typically the top predators in these cave environments. They primarily eat insects, and their only successors are fish that find their way in the caves, or occasionally other Olms. 

• Long bodies: Olms have long, thin, snake-like bodies and four legs that allow them to move easily throughout the water and underground cave systems. 

• How can we conserve this species based on its ability to adapt and environmental needs?

• Olms are currently considered vulnerable, and their main source of threat is human activity/pollution. Since they live so deep underground, it is difficult to keep a record of the total population. Olms are the only amphibians that have fully adapted to cave environments, which also means that conservation on the surface is more difficult. Ultimately, conservation for Olms requires stricter regulations to combat the pollution around their habitats, as well as carefully monitored captive breeding programs (NCBI).

• What is the average age of the Olm?

• 58-100 years old (Kidadl, 2021)

Scientific Method and Statistics

• Given that the age range for Olms is between 58 and 100, I created a sample of eleven points to solve for:

• 58, 59, 60, 66, 68, 74, 76, 82, 83, 89, 93

Hypothesis:

• How would Olms adapt to the contrasting desert environment differently from their native habitats? Let me paint picture of this new environment:

• Miles of sand and desert lie under the blistering, beaming sun. Everything about the environment is dry, except for the small streams scattered scarcely about the desert. Rocks and patches of grass line the stream, and sometimes coyotes stop by for a drink.  Fish in the stream range from minnows to pupfish to even larger “chub” fish. Lizards, snakes, and birds meet at the bank of the stream to cool off and look for food in the water/grass. During the day, it can be over 100 degrees Fahrenheit, and it drops to around  25 degrees Fahrenheit at night. 

• If Olms were placed in a desert habitat, then their population would decrease because of their adaptations and increase of threats.

• Olms that are deep underground are a white-ish color because they aren’t exposed to the sun

• Olms in the desert would produce more melanin and appear brown or black

• This means they would likely stick out in the (dry sand) and be more susceptible to predators

• Wet sand is darker, so they might have a better chance of blending in

• Olms are fully aquatic

• They would need to find some sort of stream or pond in order to sleep, eat, and breed

• Olms’ eggs are also in the water (more vulnerable to fish and weather)

• Olms only breed every decade or so, meaning that less of the already few eggs would survive

• The temperature can impact how long it takes the larvae to hatch

• Olms can go years without eating

• It is unlikely that they will starve because there are generally fish, plants, and insects in streams

• Predators/Threats:

• In the water: underwater caves are pretty safe for Olms because their enemies can’t see them, and fish only get lost in the caves occasionally

• Desert streams would mean that Olms are susceptible to birds, larger fish, and weather

• Prior Adaptations:

• Olms are mostly blind (huge disadvantage for sensing danger)

• Olms have electroreceptors and lateral lines to sense movement, vibration, etc but this may not make up for their lack of vision

• They have excellent hearing and sense of smell

(In their underwater caves, Olms are apex predators. In the desert, they would be one of the most vulnerable animals)

Final Thoughts:

Olms teach us the significance of how an environment dictates vulnerability. While this applies to many species, Olms are the only amphibians that have adapted to the deep, dark, underwater caves - so, it is imperative that their habitats remain untouched from further pollution to avoid the current downward trend of their population. Their slow reproduction and heightened sensitivity to environmental changes means that extinction may be more likely than genetic mutations or new adaptations. I was originally intrigued by the Olm due to its mysterious nature and resemblance of a small dragon. Incorporating my understanding of both evolutionary adaptations and standard deviation of a given set provided me with more insight into a species’ ability to refine its own traits based on its surroundings. 

Works Cited

More from this Author, et al. “Interesting Facts about Olms: Just Fun Facts.” Just Fun Facts | Fun and Interesting Site, 29 Apr. 2020, http://justfunfacts.com/interesting-facts-about-olms/.

Holtze, Susanne, et al. “Monitoring Health and Reproductive Status of Olms (Proteus Anguinus) by Ultrasound.” PloS One, Public Library of Science, 15 Aug. 2017, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5557490/.

Katie Jewett is a Bay Area science writer. “Saving Slovenia's ‘Human Fish.’” BioGraphic, 17 Aug. 2021, https://www.biographic.com/saving-slovenias-human-fish/.

“Did You Know? Incredible Olm Facts.” Free Ideas For Family Fun & Learning, https://kidadl.com/animal-facts/olm-facts.

“Olm.” AZ Animals, 25 July 2021, https://a-z-animals.com/animals/olm/. 

“Olm.” EDGE of Existence, 16 May 2019, http://www.edgeofexistence.org/species/olm/.

PAC2013. “Olm (Proteus Anguinus).” The Mohamed Bin Zayed Species Conservation Fund, https://www.speciesconservation.org/case-studies-projects/olm/3971.

“Proteidae.” Salamanderland, 30 June 2020, https://salamanderland.com/species/proteidae.

tetrapodzoology on November 17, 2008. “Tetrapodzoology.” ScienceBlogs, https://scienceblogs.com/tetrapodzoology/2008/11/17/the-history-of-olms.

“Underground and Unknown: Updated Distribution, Ecological Notes and Conservation Guidelines on the Olm Proteus Anguinus Anguinus in Italy (Amphibia, Proteidae).” Taylor & Francis, https://www.tandfonline.com/doi/abs/10.1080/11250003.2004.9525538.

“Weird & Wonderful Creatures: The Olm.” American Association for the Advancement of Science, 16 Mar. 2016, https://www.aaas.org/news/weird-wonderful-creatures-olm.

Yong, Ed. “The Olm: The Blind Cave Salamander That Lives to 100.” Science, National Geographic, 3 May 2021, https://www.nationalgeographic.com/science/article/the-olm-the-blind-cave-salamander-that-lives-to-100.