Albino Crayfish in Peacock Cave
There are ~40 species of blind crayfish that look just like this one, found throughout caves in North America. Cave crayfish are smaller in size than their regular open water counterparts, and as they are born eyeless, deep underground and completely without color, one might wonder how it is they survive....
Albino Crayfish in Cow Crap Cave, Tennessee
However these amazing creatures have been spotted more than 3000 feet back into cave systems (e.g. Ginnie Springs), alive and well, and they almost certainly have never seen natural sunlight! Some can live at depths of more than 200 feet, live to be more then 20 years old, but their diets are entirely muck-based! So how do they do it?
Albino crayfish perched on a bed of silt
Photo courtesy of
Agnes Milowka
Firstly, crayfish have a tough exoskeleton which supports and protects their delicate body underneath. As the crayfish grows, they shed the current one (moults) and grow a new one. If they ever lose limbs, they simply regrown them as they moult!
Albino Crayfish searching for food in Little River Cave
Although cave crayfish have no true eyes, they have an excellent sense of smell and touch, which they use to detect predators and food in their surrounding area. Functional eyes would be useless in the dark depths of caves where crayfish reside. Instead they have a much heightened perception to chemicals and vibrations, which gives them a very good idea of whats around them.
Albino crayfish foraging in Orange Grove Cave
Well equipped with their numerous antennae, 5 pairs of walking legs, and strong nippers, they scurry along the floor and roofs of caves feeding on dead and decaying plant and animal matter, isopods and copepods. Cave crayfish have a very low metabolic rate, and grow very little from year to year, so they do not need very much food to survive. When crayfish feel any movement (eg potential predators) in their vicinity, they remain completely motionless, and rely on their transparent body coloring to camouflage them wherever they are.
A closeup of an albino crayfish, its transparent color is very obvious.
This specimen was photographed in Orange Grove Cave
In order to survive cave crayfish need very high water quality, thus they can be, and are, useful tools to us in water quality indication. Unfortunately this has also worked to their demise, due to their specialized niches, population isolation through different cave systems, and a decrease of water quality on a global scale, more then half of cave crayfish are now endangered.
Close up of albino crayfish scurrying over a thick layer of silt
Photo courtesy of
Agnes Milowka
Photo courtesy of Ed Jackcon
Photo courtesy of Ed Jackcon
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