La Cueva de Los Sabinos pool 2. Photographs and videos showing the presence of sponges across multiple years A–C show photographs or snapshots from videos where sponges can be observed. Dates of observations are indicated. The continued presence of sponges throughout 2013 to 2023 suggests sponges are not accidental, but instead constitute an integral part of the underground community. Thick white arrows point to sponges, thin brown arrows point to Astyanax cavefish.