16.03.2026 – Dashers and gliders
March 23, 2026
After cancelling the morning tours due to bad weather, our afternoon guests were very lucky — they encountered a Mola mola, also known as the ocean sunfish. These unusual bony fish are a rare sighting in the waters around Madeira. They like to sunbathe at the ocean surface to reheat after deep-sea foraging dives. They can dive up to 600 meters deep searching for dense jellyfish colonies, their primary prey. The Portuguese Man-of-War, usually found on the surface of the sea, is also part of their diet. A thick, mucus-like lining in the sunfish’s mouth and digestive tract shields them from venomous stinging cells. Externally, they are protected by incredibly thick skin, up to 7.3 cm in some places. In comparison, human skin is only around 2 millimeters thick. Because jellyfish are about 95% water, sunfish need to eat hundreds of them every day (the equivalent of 20-60 kg of dry organic matter).
It is not unusual to see them sharing the same waters as the second species we encountered that day: the short-beaked common dolphin (Delphinus delphis). While both thrive in temperate and tropical open oceans, their relationship with jellyfish is completely different. Dolphins prefer to play with them; however, if they get stung in a sensitive area around their mouth, eyes, or blowhole, it can be very painful. Some researchers believe dolphins might intentionally rub against certain types of jellyfish to help slough off dead skin or parasites.
By Eva Köhle
Sightings of the day
Stenella
13:30 Short-beaked common dolphins, Sunfish
