Adult and juvenile specimens of Stygobromus allegheniensis from Ice Cave #1 at Sam’s Point Preserve. As is typical of cave-adapted organisms, this species is depigmented, has long appendages, and is fully eyeless. Nonetheless, it can detect light and actively avoids it.

 
 
  Part of: Espinasa L, Collins E, Finocchiaro A, Kopp J, Robinson J, Rutkowski J (2016) Incipient regressive evolution of the circadian rhythms of a cave amphipod. Subterranean Biology 20: 1-13. https://doi.org/10.3897/subtbiol.20.10010