Marine Life

The marine life in the cenotes is rather unimpressive. Because of the conditions found here, only a number of species manage to survive in these waters. Some cenotes are void of life while others may offer encounters with catfish, mollies, and tetras. These animals live in the freshwater found in the upper section of the cenote. In the caves, you may spot blind fish; they are completely white and have no eyes, as they have adapted to the darkness and are more energy-efficient this way.

Speleothems

The cenotes are filled with stalactites, stalagmites, and columns. The stalactites are the result of water dripping from the ceiling, resulting in buildups of calcium carbonate. Stalagmites occur when the droplets of water fall to the bottom, so the calcium carbonate builds up from the bottom upwards. Columns are just stalactites and stalagmites meeting and forming a pillar. Large rock formations take thousands of years to form, which is why it is important for divers to keep a safe distance to avoid destroying them.

Stunning Light

There’s an eerie atmosphere in cenotes, and the reason for this is the light that manages to penetrate the darkness. But there’s another factor that adds to this otherworldly experience, and that’s the hydrogen sulfide cloud. This is caused by the vegetation surrounding the cenotes; as it falls down and decomposes at the bottom of the cenote, it produces hydrogen sulfide which looks like smoke in the water. It’s like you’re swimming above an underwater swamp.

Bones and Artifacts

The tunnels of the cenotes were once dry, allowing prehistoric animals to go inside them. It’s not unusual to see the bones of animals still inside them, some dating back approximately 15,000 years. Some cenotes even hold human bones.
Since the cenotes were sacred places for the ancient Mayans, some of them contain ceramic bowls which have most likely been placed there as part of their rituals.