Glassfish

Photo: Jean-Paul Cassez · CC BY-NC

Sweepers and glassfish pack the aircraft hangars of the HMS Hermes in pulsating silver clouds that can number in the tens of thousands, their transparent bodies and reflective scales creating a living, shimmering curtain that parts and closes around divers passing through. These small planktivorous fish exploit the wreck's enclosed spaces as daytime refuge from predators, emerging into open water at dusk to feed. Their mass within the wreck creates one of the most visually immersive penetration-diving experiences in the Indian Ocean.