In this video we are in the waters in front of the Tuaredda Island in Sardinia, one of the most beautiful beaches in the Mediterranean Sea and for someone one of the most beautiful in the world. While snorkeling in these crystal clear waters I came across a long PVC tube lying on the seabed, who arrived there who knows how.
Usually everything that is left in the sea by man is colonized by marine organisms in a few years, and this plastic wreck seems to have been there not long ago, since apart from a hedgehog, some oysters and some limpets it is practically still not colonized , except for Acetabularia acetabulum, Umbrella Seaweed or Sea Umbrella.
This alga is quite common in the Mediterranean, and I am used to seeing it in the low rocky bottoms together with other algae and marine organisms. In this case it is curious to see how it was one of the first organisms to colonize this plastic wreck over its entire length.
Acetabularia J.V.Lamour., 1812 is a genus of algae of the Polyphysaceae family, widespread in the waters of warm and subtropical temperate zones including the Mediterranean sea where the species Acetabularia acetabulum is present.
Acetabularia is a single-celled organism, but of very large size and complex in shape, characteristics that make it an excellent model for the study of cell biology.
In the form, the acetabularia resembles the round leaves of a nasturtium, with a height between 0.5 and 10 cm and with three anatomical parts: a rhizoid at the bottom that resembles very short roots, a long stem in the center, and on top an umbrella of branches that can merge into a hat. The acetabulary nucleus is located in the rhizoid, and allows the cell to fully regenerate if the hat is removed. The hats of two different acetabularia cells can also be exchanged, even between two different species.
A peculiarity of the acetabularia, better known as a sea umbrella, is that at the end of autumn it loses its umbrella which regenerates in the spring.