Marine Curios #20 – Sailor’s Eyeballs, Valonia ventricosa

Sailor’s eyeballs, also known as bubble algae, are fascinating organisms found in tropical and subtropical waters, especially around mangroves and coral reefs. These green algae, scientifically called Valonia ventricosa, can grow to be quite large, reaching up to 5cm in diameter. Despite their impressive size and unique structure as one of the largest single-cell organisms, they are often overlooked by divers. Since they need sunlight to survive, they typically do not grow deeper than 80 meters.