22.09.2026 – The Start of Autumn
September 30, 2026
A large pod of spotted dolphins (Stenella frontalis) was found, but they were less curious and playful than other time, so we left them alone.
During one of their trips, our colleagues on Steno found a surprising creature floating at the surface : a silver spinyfin (Diretmus argenteus). This funny looking fish is living deep in the water column, usually between 500-700m but their range can extend to 2000m. They are found in tropical and temperate waters and their diet consists of plankton.
Sunlight completely disappears at 1000m deep and so this fish is completely in the darkness. For certain fishes, one of the many adaptations of a life in the dark is having excessively big eyes. The silver spiny-fin has a rather large pair of eyes to capture scarce photons hundreds of meters deep. Scientists found out, through genetic research, that this fish has up to 38 rod opsin genes to detect faint blue daylight and bioluminescence which is a record amongst vertebrates ! Humans only possess a single functional rod opsin gene. This is some very cool visual superpowers !
By Juliette Colançon
Sightings of the day
Ribeira Brava
09:00 Bottlenose dolphins
13:00 Atlantic spotted dolphins, Bottlenose dolphins
Steno
09:30 Atlantic spotted dolphins, Bottlenose dolphins
13:30 Atlantic spotted dolphins, Bottlenose dolphins
