Have you ever wondered what creatures lived underground in caves?
Maybe you have an idea from the latest Hollywood horror film, or more accurately BBC's Planet Earth series on Caves.
Below is how life is classified in caves, with a few questions and observations that have been made on various caving trips. Definitely scroll through the photos to check out the fascinating life occurring in these amazing places.
Subterranean life forms are classified according to how dependent they are on the underground environment. They are as follows:
Accidentals – “Critters” that have fallen, washed, and/or wandered into caves, that can live but will not become established. ie. frogs etc. It has been noticed that Accidental insect larva, and tadpoles in caves will grow larger than normal. They then begin to lose their pigment and die without completing their metamorphosis cycle. It would be interesting to know how much sun light controls this process.
Trogloxenes – Organisms that use caves for some portion of their life-cycle, but also spend part of their time on the surface. ie. bats, harvestmen etc.
Troglophiles – Can spend their entire life in caves, but also occur in similar dark, damp-surface environments. ie. salamanders, crickets etc.
Troglobites – Are cave adapted organisms that cannot survive on the surface, and must spend their entire lives in caves. They have adapted to survive and exploit their stable environment, some adaptations include:
· Loss of pigmentation
· Reduction and sometimes complete loss of eyes
· Extension of sensory structures
· Elongation of locomotory spines and claws
In the Canadian Rockies there is a small (5mm) aquatic Troglobite (Salmasellus stebanothrix, check out the photo) that is currently known in 5 locations over a 370km area. How did they get there? Under the glaciers? It would be fascinating to find out (DNA testing etc.) Also, on a recent expedition in Mexico a cave diver saw scoprions living under water (almost a mile from the surface!).
Extremophiles – This term refers to organisms that have adapted to conditions such as temperature, pH, or the mixture of atmospheric gasses that fall outside what we humans consider the normal range. Not necessarily cave dwelling organisms, they are often microbes.
Scientists are currently looking for extremophile bacteria to be potential sources for new medicines, etc. Check out this video link to find out more!
Photos by: Chris Omura and Nicholaus Vieira unless otherwise stated.