First Report of the Thermophilic Thalassoma Pavo (Linnaeus, 1758) on the Central Adriatic Coast of Italy, in Abruzzo

The Trabocchi Coast in the Chieti district of the mid-Adriatic (Italy) is one of the few rocky areas within the General Fisheries Commission GSA 17, alongside Mount Conero (Ancona 43°00'01″ N 13°52'13″ E) and the small San Nicola Rock (Ascoli Piceno; 43°32'0″ N 13°36'0″ E). This coastline is known for its biodiversity-rich bays, inlets, and submerged cliffs. Since 2015, annual biodiversity surveys have been conducted in the area, focusing on marine species richness and the identification of non-native species. In September 2024, a juvenile ornate wrasse (<i>Thalassoma pavo</i>) was documented for the first time in the middle Adriatic during an underwater visual survey at Trabocco Punta Torre, a key site along the Trabocchi Coast near artificial and biogenic reefs. This record extends the known distribution of <i>T. pavo</i>, a thermophilic species previously reported only along the southern Adriatic coast of Puglia. This is the first confirmed sighting on the middle and northern Adriatic coast of Italy. The discovery highlights the importance of ongoing biodiversity monitoring to track changes in marine ecosystems, particularly as the Adriatic Sea faces environmental shifts linked to climate warming. The presence of <i>T. pavo</i> in this area suggests the potential for the species to establish populations in previously uninhabited northern regions. Further research is needed to explore the role of biotic and abiotic factors-such as water temperature, current patterns, and habitat availability-in the survival and potential reproduction of <i>T. pavo</i> in the middle Adriatic. The observation contributes to the broader understanding of the meridionalization process in the Adriatic Sea, where rising water temperatures are facilitating the northward expansion of thermophilic species. Continuous monitoring is recommended to assess the long-term viability of <i>T. pavo</i> populations in the Adriatic Sea and better predict the impacts of ongoing climate change on marine biodiversity.