01.04.2026 – Larger for a reason!

Fin whales (Balaenoptera physalus) again – how lucky our guests were to encounter the second-largest animal on the planet! Female fin whales are only about three meters shorter than female Blue whales (Balaenoptera musculus). This difference is a great example of sexual dimorphism – a phenomenon where males and females of the same species differ in appearance. While it can show up as variations in color or features like horns in other animals, in baleen whales it is expressed in size, with females being larger because they bear the greater energetic demands of reproduction.

In some deep-sea anglerfish, sexual dimorphism is taken to the extreme: males, dramatically smaller than females (often just 5–10% of the female’s length), attach to them and fuse into their bloodstream, becoming lifelong reproductive companions.

And their luck didn’t stop there – today was a day of plenty. During almost every tour, we also encountered Loggerhead sea turtles (Caretta caretta) basking in the sun to rid themselves of parasites and rest, Short-beaked common dolphins (Delphinus delphis), as well as Portuguese man o’ war (Physalia physalis) and Violet sea snails (Janthina janthina).

By Eva Köhle

Sightings of the day

Ribeira Brava

09:00 Short-beaked common dolphin

13:00 Fin whale, Short-beaked common dolphin

Stenella

09:30 Short-beaked common dolphin, Bottlenose dolphin, Loggerhead turtle

13:30 Fin whale, Short-beaked common dolphins

16:00 Fin whale, Loggerhead turtle