wow, that's a lot of jellyfish...
in one of palau's jellyfish lakes.
these dudes were isolated in a saltwater lake some time back (sinking sea levels, rising island or maybe hitching a ride on the cormorants that fish both there and in the ocean) and have lost - as the covering-our-ass sign says - "virtually all stinging ability"; apparently some people develop a sensitivity to them after repeated exposure. they have photosynthetic algae in 'em, and live off the sugar that algae produces. they follow the sun across the lake during the day, then sink down to a nitrogen (and hydrogen sulphide, so no diving) rich layer at night and move back to the sunrise side.
it's a very creepy place when you first run into the jellies. at first there're just one or two, then as you get into the sun, there're thousands of 'em. it took me a while to get over the moment of 'ahhh! jellyfish sting!' panic when they lazily bumped into me. pretty cool after I did though.
and they're mastigias jellyfish, in case you care.
ever so briefly the most interesting photo for January 16, 2006. hovers between about 5 and 10 these days.