The ocean sunfish in the Mediterranean: new insights into an enigmatic species
With its large, flattened body, the ocean sunfish (Mola mola) is one of the most distinctive and recognizable inhabitants of the Mediterranean Sea. Encounters with this species are uncommon, but when it appears at the surface, it rarely goes unnoticed. Yet, despite its large size and wide distribution, many aspects of its ecology remain poorly understood, particularly in the Mediterranean.
A new study coordinated by ISPRA has sought to fill some of these knowledge gaps by bringing together the available scientific literature on the species, 14 years of ferry-based observations, and the latest environmental DNA (eDNA) data.
The findings from long-term visual observations were further supported by environmental DNA data collected between 2022 and 2024 as part of the European LIFE Conceptu Maris project. By analyzing genetic traces released by organisms into the water, researchers were able to detect the presence of ocean sunfish even at night and characterize the biological communities associated with its occurrence. These frequently included several species of lanternfish, such as Hygophum benoiti, a known prey species of the ocean sunfish, as well as the jellyfish Pelagia noctiluca. These associations, observed mainly during nighttime hours and involving organisms characteristic of productive waters, provide new clues about potential trophic relationships and the use of areas rich in potential prey.
Overall, visual observations and environmental DNA provide complementary insights, revealing links between ocean sunfish distribution and environmental conditions while offering new information about its ecology.
However, the literature review also highlights how much remains to be discovered: knowledge of the ocean sunfish in the Mediterranean is still limited. Integrating scientific literature, long-term monitoring, and eDNA data therefore helps add new pieces to the puzzle of one of the most enigmatic species inhabiting our seas, while improving our understanding of how its distribution may respond to the ongoing changes affecting the Mediterranean.
Reference: Ciavoni, E.; Pasanisi, E.; Atzori, F.; Azzolin, M.; Campana, I.; Carosso, L.; Castelli, A.; Colombo, S.; Costantino, M.; David, L.; Di Meglio, N.; Roul, M.; Garcia-Garin, O.; Gregorietti, M.; Grossi, F.; Maffucci, F.; Moulins, A.; Pellegrino, G.; Pignata, E.; Pupillo, G.; Rota, A.; Sarà, G.; Scuderi, A.; Tepsich, P.; Valsecchi, E.; Vighi, M.; Arcangeli, A. (2026). Ocean Sunfish M. mola in the Mediterranean Sea: Shedding Light on an Enigmatic Species through 14 Years of Spatial and Environmental Assessment. Marine Environmental Research, 108429. https://doi.org/10.1016/j.marenvres.2026.108429
