Name: The Top Predator Deep Under Texas
Uploaded: 2021-01-04T19:00:51.000Z
Duration: 6 min 10 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

dug a well plunging 188 feet into the earth

And when they did, water rushed to the surface

flushing out dozens of undiscovered creatures

These animals had never seen the surface.

Perhaps the strangest-looking animal in this catch

Upon discovery, herpetologist Leonhard Stejneger

Narrator: These unusual  conditions are contained

this species of salamander has ever been recorded.

So, how did these caves create the "profound differences"

In other words, how did they end up looking so weird?

Tom Devitt: Take the dates with a grain of salt,

from its most recent common ancestor probably around

somewhere between 10 and 15 million years ago.

Narrator: And geologists  estimate that the aquifer

had been hundreds of millions of years in the making.

During the Jurassic period, some 200 million years ago,

the area was occasionally  covered in shallow oceans,

but when the area was  dry and exposed to air,

the rocks were eroded by  weather to make porous caverns.

Eventually, a shallow basin of water and sediment

But rainfall continued  to eat away at the earth

to create the deep fissures and caverns inside the aquifer.

some salamanders crawled beneath the surface,

seeking refuge in the cool and stable environment

And over the course  of millions of years,

these salamanders adapted to  the aquatic subterranean caves

like blood-red gills  outside of their body,

the salamanders simply didn't need to see,

and energy used for sight would only be wasted.

Today, only two small black dots just under the skin

Those dots likely only detect if it's light or dark out.

also applies to their silvery white skin.

Skin pigmentation  usually protects animals

but both of those are nonissues for the blind salamanders,

who don't have to worry  about the sun or predators.

are at the top of the food chain in this ecosystem,

feeding on various  crustaceans, like shrimp.

And even though they can  go months without eating,

several features help  them capture their prey.

similar to the lateral line found in fish,

to changes in water  movement and pressure,

Another helpful feature is their large head,

Danté Fenolio: All of those things are characteristics

in a very, very  challenging environment,

so that's why they look the way that they do.

Narrator: Fenolio is one of the lucky few

who've seen these elusive salamanders up close.

Last year, his team at the San Antonio Zoo

bred Texas blind salamanders for the first time in a lab,

and they've repeated their success four more times.

They're aiming to protect  the species from extinction,

since the salamanders have  been endangered since 1967.

Two main things threaten the Texas salamander's survival.

The first is contamination from wastewater runoff.

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The Top Predator Deep Under Texas

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