Aerial Image (IMAGE) University of Washington Caption Freshwater snails that transmit schistosomiasis thrive in unrooted, floating vegetation that can be seen in aerial images. In this photo, the dark, patchy vegetation in the water is the ideal habitat for snails. Credit Andrew Chamberlin/Stanford University Usage Restrictions Photo credit required. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.