Surviving in caves is hard and calls for a lot of adaptions. The climate underground is damp and cool most of the time, and lack of light makes the available food rather scarce. Only few species have adapted to this environment and some have perfected their skills. Things like seeing and colorful skins or feathers lose importance and regress over generations.
Cave animals are divided in full-time cave-dwellers and animals that prefer caves only part of the time. Bats like to use caves for hibernation while they spend the months when there is plenty of food in their summer habitats.
Mexican Tetra (Astyanax fasciatus)
Also called Blind Cave Fish, this tetra is well adapted to living in caves. While the surface light-loving form is common over all of Central America from the southern US to northern South America, the cave fish are found only in an 80 miles mountain range in eastern central Mexico. There they are known to have colonized about 30 cave systems. While the surface form of Astyanax has big eyes, a dark back and silvery flanks, the cave fish shows the typical features of an animal living permanently underground: eyes degenerated to useless small rudiments, coloration almost gone.
Whip Spider (Damon gracilis)
Whip spiders (Amblypygi) can live both in caves and aboveground. There are 130 known species around the world. The whip spider we show in the exhibition is originally from Angola and Namibia and feeds on crickets and moths.
Due to its extremely flattened body the spider can hide under rocks. Its long sensory legs help it to feel the terrain.
Segeberg Cave Beetle (Choleva septentrionis holsatica)
This copper brown beetle, five millimeters long and found only here in the Kalkberg cave, is also an endemic species. Its population of about 15000 reaches its greatest number while the bats are hibernating. It has adapted perfectly to its environment for it feeds on bat dung and carcasses and also acts as a kind of cleaning crew. The cave beetle needs its temperature of 9° Celsius (48° Fahrenheit) and nearly 100% humidity, it could not survive outside.