Our planet is full of surprising and varied places that are home to a great diversity of life, but none like caves. These openings in the earth lead us into an underground world of darkness and mystery where we often find unique life forms that have adapted to survive in such an unusual and challenging environment.
Caves are dark and often inhospitable environments, with conditions that can vary drastically depending on their location and formation. They can be wet or dry, hot or cold, and many are completely insulated from the surface. Despite these extreme conditions, life has found ways to thrive.
In order to survive in caves, animals have evolved a number of incredible adaptations. These adaptations have been given to overcome the restrictions of living in the dark, lack of food and extreme temperatures. For example, many cave animals have lost pigmentation in their skin, as color has no advantage in the dark. Some have completely lost their sight, relying instead on other senses, such as touch and hearing, to move and forage.
Additionally, many burrowing species have evolved to have slower rates of metabolism, in order to survive with limited food availability. Cave animals typically have longer life cycles and a lower reproductive rate than their surface counterparts, since resources are limited and the environment is stable.
Cave animals are a prime example of how life can adapt to the most extreme and challenging conditions. On this trip we will see some of the most fascinating caves in the world and meet the incredible creatures that live there.
1. Arachnids from Movile Cave, Romania
Movile Cave, located near the city of Mangalia in southeastern Romania, is home to a multitude of unique arachnids. These arachnids, along with other invertebrates in the cave, have evolved to survive in complete darkness, feeding on a layer of bacteria that feed on hydrogen sulfide and carbon dioxide from the cave’s hot springs. Reaching the cave involves a descent of 20 meters and a journey through narrow passages, a journey that is not for the faint of heart, but one that offers the chance to see creatures found nowhere else.
2. Blind Fish from Lechuguilla Cave, New Mexico, USA
Astyanax mexicanus , also known as the blind cave fish, is a famous inhabitant of the subterranean caves of Mexico and south Texas, including Lechuguilla Cave. As its name suggests, this fish has lost its eyes due to evolution in the complete darkness of caves. Instead, it has been developed with a highly-tuned sensory system that allows it to detect changes in water currents and vibrations. Unfortunately, the Lechuguilla cave is not open to the public, but you can find blind fish in the region’s accessible caves.
3. Bats from Deer’s Cave, Borneo, Malaysia
Deer’s Cave in Gunung Mulu National Park is known for its colony of millions of bats. Every night, bats emerge from the cave in a phenomenon called “bat exodus”, a true wonder of nature. The park is accessible by plane or boat from the city of Miri in Malaysia, and guided tours allow visitors to experience this spectacle first-hand.
4. Crustaceans from Ox Bel Ha Cave, Quintana Roo, Mexico
Ox Bel Ha Cave, one of the largest underwater cave systems in the world, is home to an impressive variety of crustaceans, many of which are endemic to the cave. Since the cave is filled with water, visitors must be certified scuba divers to explore it, but those who can will be rewarded with the chance to see these wondrous creatures in their natural habitat.
5. Fireflies from Waitomo Cave, New Zealand
The Waitomo cave fireflies are known for their impressive bioluminescent display. These insects, specifically the luminous Arachnocampa species, emit a soft glow that illuminates the darkness of the cave, creating a fairytale atmosphere. Fireflies are a rare example of bioluminescence in cave life, and Waitomo Cave offers the unique opportunity to observe this phenomenon1. Waitomo Cave is located on the North Island of New Zealand and is easily accessible by car from all major cities in the country.
6. Salamanders from the Postojna and Predjama Caves, Slovenia
The Postojna and Predjama Caves in Slovenia are home to the Proteus anguinus , or “blind salamander,” a fascinating and unique creature. This aquatic salamander is completely blind, with translucent white skin and an elongated body that is more reminiscent of a worm than a salamander. It is a wonderful example of how life adapts to the conditions of underground caves1. The Postojna Caves are located in the city of Postojna, in southwestern Slovenia, and can be reached by car or by train from the capital Ljubljana.
7. Snails from the Lukina Jama-Trojama Caves, Croatia
The Lukina Jama-Trojama caves in Croatia are home to a unique species of snail, the Zospeum tholussum . This tiny snail is only a few millimeters in length and has a nearly transparent shell. It is one of the slowest species in the world, moving only a few centimeters per week1. To get to Lukina Jama, one of the deepest cave systems in the world, you’ll need to join a spelunking expedition, as it’s not open to the general public.
8. Blind Crabs from the Cave of Jameos del Agua, Lanzarote, Canary Islands
Los Jameos del Agua, a series of volcanic caves on the island of Lanzarote in the Canary Islands, is home to a unique species of crab, the Munidopsis polymorpha . This small crab, also known as the blind crab from the Lanzarote caves, is albino and lacks eyes, as it has evolved in the darkness of caves. Despite their small size, barely one centimeter long, they are a main attraction for visitors to Jameos del Agua.
The world’s caves are time capsules and reservoirs of biodiversity, harboring a wide variety of fascinating and unique life forms. From unusual and endemic creatures to those that have developed extraordinary abilities to survive in the dark, these cave animals offer us a unique insight into evolution and adaptability. The next time you find yourself near one of these caves, don’t pass up the opportunity to explore and you just might come face to face with one of these wondrous creatures.