09.05.2025 – Special bubbles in the middle of the waves

A morning with sun, rain and some waves. Both boats were able to see Short-finned pilot whales (Globicephala macrorhynchus) and Bottlenose dolphins (Tursiops truncatus), after a bit of searching. On the Stenella tour we also had Portuguese man o’ wars (Physalia physalis). I’m sure the Ribeira Brava guests also got to see some. On our tour, Daniel fished special bubbles in the middle of the waves out of the water. Bubble rafting snails (Janthina janthina) are incredibly beautiful.

The Bubble rafting snail lives floating freely on the sea surface. It keeps itself there with the help of a self-constructed foam nest of air bubbles, which it stabilises with mucus. It has a striking violet to blue-violet colouring, which presumably serves as camouflage from above against the sky (bluish) and from below against the sea (light). The violet snail feeds mainly on cnidarians such as By the sea sailors and Portuguese man o’ wars, whose poisonous cnidocytes it can partially take over. When in danger, the Bubble rafting snail can secrete a purple liquid, which presumably serves to deter predators – similar to ink in squid. The day before yesterday, a Bubble rafting snails felt the need to secrete this liquid on my hand. The violet colour lasted quite a while.

If you would like to help protect Pilot whales and Bottlenose dolphins, you can find the petitions here: https://www.lobosonda.com/marine-protection/

by Fatima Kutzschbach

Sightings of the day

Ribeira Brava

09:00 Pilot whales, Bottlenose dolphins

Stenella

09:30 Pilot whales, Bottlenose dolphins, Bubblerafting snail, Portugueses man-o-war