The EUROPE stamps build awareness of Europe's common roots, culture, history and goals. The theme of 2024 is underwater flora and fauna, and the motifs of the Croatian Post Mostar are the bivalve date shell and the green alga Acetabularia acetabulum.
The date shell is a marine bivalve from the mussel family (Mytilidae) that lives on the shores of the Mediterranean Sea (including the Adriatic Sea), the Atlantic and the Red Sea. It inhabits cliffs and standalone rocks to which it clings as a larva and starts drilling them. As it grows, so does the cavity it inhabits. Its shell is elongated, cylindrical and up to 12 cm long. It grows very slowly, about 5 cm in 10 to 20 years. Date shells are considered an exceptional delicacy and their fishing is prohibited in many countries.
The Acetabularia acetabulum is a species of green algae from the Polyphysaceae family, which is widespread in the Mediterranean and Adriatic seas. It got its Croatian name (Jadranski klobučić - Adriatic cap) because of the visibly pronounced radial ribs on the white mushroom-like or umbrella-like cap. It consists ofthree parts: a rhizoid (a protrusion from the lower epidermal cells of mosses and algae), a 8 to 10 cm long stalk and a cap. An interesting fact is that the entire alga is one cell. (source:HP Mostar)
