Deep within cave systems, creatures live their entire lives shrouded in darkness. Some, like the aptly named blind catfish, have even evolved to be entirely eyeless. Others, like certain cave spiders and centipedes, have elongated limbs that serve as sensory organs. Nearly all are semitranslucent and devoid of pigment. These adaptations to the dark are known as troglomorphisms. If you venture into the word’s etymological depths, you’ll find the Greek root morph, meaning form or shape, lurking behind the prefix troglo, or cave-dwelling.
This appeared in the June 2020 issue of Discover magazine. Subscribe for more stories like these.