SPELUNKING FOR SPIDERS

The immense expanse of nan Nullarbor Plain, connected accepted Mirning land, is an enigmatic and captivating landscape.

Once an ancient seafloor, nan arid ecosystem covers complete 200,000 quadrate kilometres of desolation, traversed only by Australia’s longest, straightest highway. 

Hidden beneath nan monotonous godforsaken scenery lie limestone karsts.

These formations person been hollowed retired by rainfall complete respective millennia to create immense and little-understood cave systems. 

The entrance. (credit: Andrew Stempel)

AN UNDERLAND ADVENTURE

The Yalata Bush Blitz expedition, successful 2021, was an effort to archive nan area’s biodiversity.

Scientists were alert that large  blind, cave-dwelling spiders, known as Troglodiplura existed successful nan Nullarbor, but each type were only known from fragments of exoskeleton and a fewer juvenile spiders.

That was astir to change.

Deep wrong nan Swiss-cheese-like cave systems, arachnologist Dr Jess Marsh and speleologist Andrew Stempel  became nan first group connected grounds to spot a surviving big Troglodiplura, this 1 a very ample female.  

Andrew was 1 of nan caving experts hired to facilitate nan underground journey.

“We entered done a small solution pipe,” says Andrew. “A fewer meters across, possibly 5 meters deep.”

A solution pipe is simply a deep, vertical spread successful nan ground, for illustration a sinkhole. (Credit: Andrew Stempel)

From there, nan intrepid explorers zigzagged deeper arsenic they crawled done horizontal openings and rappelled down vertical sections.

“And past each I perceive is group yelling from further into nan cave,” says Andrew.

University of Adelaide researcher  Dr Jess Marsh was 1 of nan voices.

“They didn’t person a large capable vial to seizure nan thing,” says Andrew.

At 1 constituent he slid into a cramped crevice to retrieve a spider pinch his bare hands.

TROGLOMORPHIN’ POWER RANGERS

Jess says nan acquisition was unforgettable.

“I will ne'er hide seeing 1 for nan first time,” says Jess.

“It was conscionable like: ‘Oh, location it is’.”

“They’re beautiful animals. Completely eyeless.”

The spiders are immense – almost nan size of your hand. Genetically related to trapdoor spiders, they person gigantic fangs.

Female Troglodiplura beirutpakbarai successful its earthy habitat.
Credit: Steve Milner (not for reproduction)

“We cognize very small astir them for specified a large, awesome spider.”

DARK DWELLERS

Troglomorphism is nan word applied to animals that evolved to unrecorded successful nan complete acheronian of a cave. 

“They’re globally important because they’re amongst nan astir troglomorphic primitive spiders successful nan world,” says Jess.

“They show a scope of adaptations, including a complete nonaccomplishment of eyes and elongated limbs.” These adaptations are emblematic of troglomorphic creatures. So is simply a alteration successful tegument pigment, acknowledgment to nary vulnerability to nan sun.

Caption: Troglodiplura beirutpakbarai exhibits little depigmentation than different troglomorphs.
Credit: Steve Milner (not for reproduction)

This uncommon type was thought to only hap successful a azygous cave, but were discovered successful 3 caves separated by much than 25kms. 

This suggests these unsighted spiders whitethorn recreation and dispersed their genes betwixt nan caves.

“It was very unexpected,” says Jess.

“I deliberation it’s really exciting…looking astatine these imaginable subterranean dispersal mechanisms.” 

“It’s for illustration highways underground.”

Caption: Somewhere beneath nan Nullarbor.
Credit: Steve Milner (not for reproduction)

A MULTIFACETED THREAT

Caves mostly person a accordant somesthesia year-round.

The Nullarbor caves are nary exception, contempt ample variations successful nan above-ground temperature. This intends immoderate changes to nan situation will impact nan type surviving within.

“I deliberation foxes are a cardinal threat, immoderate of nan caves that we went into, location were dens and scat correct through,” says Jess.

The Troglodiplura had apt been nan apex predator of nan Nullarbor cave systems for thousands of years.

Despite their tremendous fangs, they seemed to beryllium docile, not reacting aggressively to nan beingness of nan scientists aliases cavers. This makes them easy prey for quiet foxes.

European Red Fox
(Credit: Harley Kingston via imaginative commons)

THE RISK FROM ABOVE

Another imaginable threat to this spider type is nan projected Western Green Energy Hub.

Over nan adjacent 15 years, it intends to create nan world’s largest renewable power hub of 25 cardinal star panels and 3000 upwind turbines, successful a improvement letter cover of 22,690 km2.

The improvement of renewable energies is paramount to combat ambiance alteration and ambiance alteration itself represents a important threat to nan endurance of endemic cave spiders.

Wind turbines and Mt. Hood
Credit: Lamoix via imaginative commons

However, nan consequence of harm to nan caves is high. The underground dispersal networks uncovered by nan researchers coming an other challenge.

“Developers person to return into relationship a overmuch broader area than conscionable a peculiar cave,” says Jess.

“There are astatine slightest 2 caves that clasp type of Troglodiplura wrong that improvement footprint, perchance more. So nan imaginable for extinctions is high.”