Tasmania has some of the longest and deepest cave systems of any Australian state, and some of the most diverse and unusual subterranean fauna in the world. Ecologically, caves are somewhat analogous to islands, in the sense that both experience isolation from the outside, which allows for increased endemicity, or creatures that evolve in one place and are found nowhere else. Tasmanian Cave animals include "spiders, crickets, beetles, slaters, snails, harvestmen, millipedes, pseudoscorpions and many other invertebrates."
The Tasmanian Cave Spider, Hickmania Troglodytes, has become an iconic species for conservation. With a legspan up to 18cm (that's 7 inches!), it is the largest spider in Australia. It lives near the entrances, twilight and transition zones of caves, and eats primarily cave crickets. Apparently it can live up to two or three decades, an order of magnitude longer than other spider species, and has an unusual reproductive behavior in which the female guards a silk-wrapped eggsack for almost a year before the eggs hatch (As with some other spiders, however, mating is dangerous for males, who sometimes end up a post-mating snack for the females!).
These unusual features help mark the Tasmanian Cave Spider as a distinct subfamily of arachnid. They are some of the last surviving remnants of a Gondwanan subfamily, and their closest relatives live in Chile. Adapting to live in caves has allowed this evolutionarily distinct lineage to survive for millions of years after their relatives went extinct. We might be seeing more of them soon, as fantasy-horror writer Neil Gaiman is making a documentary about them.
Places that would be cool to go: Mole Creek Cave, Hastings Cave and Thermal Springs, Gunns Plains Cave.
Articles: http://www.parks.tas.gov.au/indeX.aspX?base=24499, http://www.abc.net.au/news/2015-01-17/author-neil-gaiman-drawn-to-film-about-tasmanian-cave-spider/6020080
I would LOVE to check out the caves! They look crazy cool
ReplyDeleteSo this is really scary for me to hear about--I'm actually really afraid of spiders and its the only thing I am apprehensive about concerning our trip. Seeing the picture on the blog freaked me out, but I'm forcing myself to comment on it to have to look at the picture again and maybe get a bit used to it. But seeing seven inch legged spiders in person? Thats gonna be rough for me if it happens.
ReplyDeleteBrittany Hallawell