(see some background at the speculative evolution forum)
Lake Vostok was sealed under Antarctic glaciers as early as 25 million years ago and remained entirely untouched until February of 2012, when a team of Russian scientists drilled past its surface. The water taken from the lake has not yet been analyzed, but it’s only a matter of time until we get that analysis, plus sediment samples, robot probes, and manned expeditions.
What will they find?
Antarctica was a very different place 25-14 million years ago, with cool, damp southern-beech forests similar to southern South America and New Zealand. Moss, diatoms have been found in fossil beds in the Dry Valleys region, descendants of which might have survived in lake Vostok.
Or not. With no light to drive photosynthesis, there would need to be some other source of energy. That might be chemosynthesis driven by bacteria digesting the rock under the lake, or even better from the minerals released by hot springs, as in hydrothermal ecosystems in the ocean. Because it’s more fun that way, let’s assume we have the base of the food chain is mats of chemosynthetic bacteria.
Cypridoidean ostracod fossils have been discovered in Miocene lake sediments in Antarctia, making them a shoe-in for Vostok species. Despite their puny wikipedia page, ostracods are very cool crustaceans, which swim around in bivalved shells, like a shrimp shoved into a clam. Giant versions of these usually planktonic creatures might be Vostok’s answer to the giant, spiky, awesome amphipods of Lake Baikal.
Marine species might be a stretch since Vostok water is fresh, but I think 25 million years and a poor fossil record give us enough wiggle room to permit descendants of Hoploparia lobsters and Atarctidromia crabs. See also echinoids, bivalves, bryozoans.
Fish are probable too, although my Google-foo has been unable to find a particular kind.
So some ideas for Vostokian lifeforms are:
Chemosynthetic bacteria, perhaps living in concert with Antarctic lichens or mosses.Or, you could have sessile ostracods using the bacteria the way Riftia worms do.
Other ostracods! Big one, little ones, grazers, predators. Perhaps huddling together for warmth in big, mobile colonies.
The same could work for fishes. Imagine large fishes with smaller ones living commensurally around them, surrounded in turn by smaller fishes or ostracods and so on. Call them “infinitems”
Plus of course all the “normal” forms of deep-sea fishes, including giant mouths and luminescent lures.
And giant glowing bryozoans? Say yes!
UPDATE!
As of February, there HAS been sampling of the water of a subglacial lake (lake Whillans) http://onlinelibrary.wiley.com/doi/10.1002/2013EO060004/abstract although the only report I could find of the result was this http://onlinelibrary.wiley.com/doi/10.1002/scin.5591830511/abstract. And Vostok should have been sampled a year ago…I smell a cover up by the world-ruling reptilian conspiracy!
However, there are definitely microbes down there. Including autotrophs and a microbial ecosystem “capable of performing nitrogen fixation, nitrogen cycling, carbon fixation and nutrient recycling” according to http://www.mdpi.com/2079-7737/2/2/629 The article also mentions. “Psychrophiles and thermophiles [which] indicate a cold lake with possible hydrothermal activity” sampled from the ice above Lake Vostok.
So I’m feeling pretty good about my ostracods.
UPDATE 2
MSidKelly suggested copepods and yes! In fact, they are already in Antarctic lakes (the ones not currently under glaciers at least—didn’t know the continent had any of those…) . Here’s hoping they look as scary as this one.
Rotifers and tardigrades are also a good bet.
And shout-out to Turbofanatic for a more-awesome-than-mine Vostok ecology with giant caecelians and natural nuclear fission at the base of the food chain.
UPDATE 3
Subglacial Lake Vostok (Antarctica) Accretion Ice Contains a Diverse Set of Sequences from Aquatic, Marine and Sediment-Inhabiting Bacteria and Eukarya (see the New Scientist report on same)
And Slate.com’s recent thing on the haloarchaea in Deep Lake Antarctica
Geeze, I’m going to have to make a whole new page for this stuff.