A single jellyfish at Jellyfish Lake in the Rock Islands at the Republic of Palau.
Jill writes, "The most unique thing we did was snorkel in Jellyfish Lake, which is an inland salt water lake (water soaks through the limestone), filled with millions of stingless golden jellyfish. They have evolved to get their nutrition from symbiotic algae, so they migrate across the lake following the sun. For more explanation, see en.wikipedia.org/wiki/Jellyfish_Lake. For us, as you swim from the dock, you start to see one or two of the golden jellyfish..."