Weird Nature
343 voters

The Creepiest, Most Alien Creatures That Only Live In Caves

Updated July 14, 2020 1.3k votes 343 voters 28.7k views13 items

List RulesVote up the creatures you'd least like to encounter in a cave.

Despite what you’ve been led to believe, planet Earth is practically unchartered territory. About 71% of its surface is covered in water too deep and dangerous to explore. Even on land, unexplained mysteries creep up on all sides, beneath ceilings of dangling stalactites. Caves - and the creatures that live in them - are unlike anything you've probably ever seen before. If anything, they’re more akin to space aliens and the monsters drawn up by authors of science fiction.

Creatures that only live in caves are known as troglobites or troglophiles. Troglobites are obligatory cave dwellers who cannot survive outside of this natural habitat. On the other hand, troglophiles can survive outside of these caverns, but they choose to remain within their confines for the vast majority of their lives. Crazy cave creatures are of two varieties, troglofauna (animals of the land) and stygofauna (inhabitants of the sea).

Here are some mindboggling troglobite facts that prove, once and for all, that a strange, inexplicable universe is footsteps away as opposed to light years ahead.

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    A Hausera Has A Very Strange Body

    Photo: Leal-Zanchet A, Souza S, Ferreira R / Wikimedia Commons / CC-BY 4.0

    This wormy looking guy has some of the most baffling anatomy known to man. He’s a subterranean troglobite from a family of freshwater triclads. Hausera made history when it became the first cave dwelling species of its kind to be recorded in South America. Since then, it has continued to astound the scientific community with its little oddities, which include ovaries positioned within close proximity to the brain, genitalia that seem to communicate with the intestine, and a completely eyeless body void of any sort of pigment.

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    Phreatichthys Andruzzii's Biological Clocks Don't Rely On The Sun

    Phreatichthys andruzzii are an amazing example of a highly adapted subterranean species. Found in the deep sea caves of Somalia, these non-pigmented ray finned fish are entirely blind and suspected to have been dwelling in cave environments for more than 2 million years. They fall under the classification of stygofauna troglobites, or obligate nautical cave dwellers. They survive by consuming fallen sea insects and other aquatic debris.

    This small, silvery species has been the subject of study and controversy for many different reasons. Firstly, it is the one and only animal to be discovered on earth whose biological clock does not rely on the light of the sun to function. Secondly, since it appears to have survived for millions of years without the presence of sight, its numerical acuity - or the ability to process numbers and time - has been studied by scientists. Why? Because these fish can differentiate numbers and time without being able to see. 

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    Texas Blind Salamander

    Photo: Photograph courtesy of Joe N. Fries, U.S. Fish and Wildlife Service / Wikimedia Commons / Public Domain

    The troglobite amphibian known as the Texas blind salamander wears its gills on the outside, and they are a terrifying crimson shade. Surviving on cave dwelling shrimp and snails, this creepy looking salamander spends its life in utter darkness, with spots for eyes and virtually no pigment upon its flesh. Though the salamander may be blind, he is the ruler within his confined, obligated habitat, the head honcho of the Texas cave system, so to speak.

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    The Kaua'i Cave Amphipod Has Played A Huge Part In Hawaii's Ecosystem For Five Million Years

    The Kaua'i Cave amphipod is an organic eater, crawling blindly through the darkness of the Hawaiian cave system, prey for an endangered predator known as the Kaua'i Cave wolf spider. Both the spider and this amphipod have some things in common though, namely blindness and the looming possibility of extinction. Stakes are high for this strange, ghostly looking creature whose ancestors appear to have played a pivotal part in Hawaii’s ecosystem for at least five million years or more.