We kayaked in a pond where we have done so for the last almost 20 years, and saw something new to us! Where there are waterlilies growing, we saw grayish blobs floating just under the surface. When we got closer, we realized they were attached to the lily stems on one side. If we touched them they dropped and then floated back up. They felt slimy in the same way as the underside of the lily pads. They have convolutions just like a brain. Wild!!