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Specialized habitats

CAVES

A whole field of biology called biospeleology is

dedicated to the exploration, discovery, and study

of organisms that inhabit caves. Caves provide

a very stable environment: in their deepest parts

almost totally isolated from surface influences;

but the cold, damp, and perpetual darkness, and

limited supply of nutrients, make them hostile for

most life. There is a spectrum of cave insects, from

surface fauna that has temporarily moved into the

shallower and more accessible parts of caves, to

so-called true troglophiles, species that have

adapted over long periods of time to cave

conditions. The latter, among beetles, are either

predators (such as the families Staphylinidae and

Carabidae) or scavengers (Leiodidae), since the

ecosystems lack living plants (which need sunlight

left | Leptodirus

hochenwartii (Leiodidae)

A true troglophile,

this eyeless beetle from

the Dinarides in the

Balkans shows very

long limbs and

antennae.

opposite | Duvalius

gebhardti (Carabidae)

An eyeless ground

beetle from caves

in Hungary. Many

troglophiles lose eyes

and most of their

pigmentation.

for photosynthesis). Instead of plants, cave

ecosystems are based on detritus and organic

matter either carried in by water or deposited

by larger inhabitants, such as the dung and

carcasses of bats or cave-dwelling birds. True

troglophiles have a distinctive set of adaptations:

because of the darkness, they often lack eyes and

pigmentation. To compensate for the lack of

light and the uselessness of eyesight, many have

developed long, slender limbs and antennae to

enable them to feel for food.

Experts studying cave fauna often say that

those large caves that humans can enter and

explore are, from an insect’s point of view, just

the most accessible of many holes in a complex

network of interconnected crevices, gaps, and

fissures in the porous rocks. The troglophile