‘Rare’ sea creature with ‘leaf’-like body found in tide pool in Italy. See it

Along the rocky coast of eastern Italy at night, researchers scanned a tide pool in hopes of seeing something interesting. A “leaf”-like sea creature caught their attention — and for good reason.

It turned out to be a “rare” and first-of-its-kind sighting for the Adriatic Sea.

A team of researchers visited Passetto Beach, Ancona, in March as part of an ongoing project to survey molluscs, snails and slugs in the rocky tidal pools, according to an Oct. 24 study from the peer-reviewed journal Check List.

During the nighttime low-tide surveys, researchers scoured the various pools and found a brightly colored sea slug, the study said. They photographed the animal and identified it as Caliphylla mediterranea.

Caliphylla mediterranea are a “rare” and “poorly known” species of sea slug, researchers said. They are herbivores that feed on the cells within green algae, giving them a “vivid green/brown coloration.”

Photos show the roughly 1-inch-long sea slug and its “numerous leaf-shaped” outgrowths. “Small red and white dots” are scattered across its body, the study said.

“This finding constitutes the first record of this species for the Adriatic Sea and one of the few for the whole Mediterranean basin,” researchers said.

“Although (Caliphylla) mediterranea was originally described from Naples, Italy, subsequent observations have been scarce in the Mediterranean Sea and almost restricted to the western basin, with only a few outdated records available so far,” the study said.

Researchers described the Caliphylla mediterranea sighting at Passetto Beach as “quite unexpected” and an example of “the importance of continued monitoring of this area.”

Passetto Beach is emerging as “a hotspot of neglected and/or unknown” marine life, researchers said, but the site is better known as a popular summer spot. The cliffside beach has over 100 “artificial caves” built as shelters for fishing boats and later turned into “houses and meeting places,” according to a 2022 study about the site.

A YouTube video from MaPa RoNNiE shows the rocky coastline. Passetto Beach is on the northeastern coast of Italy and a roughly 180-mile drive northeast from Rome.

The research team included Luca Paoletti, Yann Toso, Egidio Trainito, Michele Solca and Giulia Furfaro.