Diversity and behavior of sea slugs (Heterobranchia) in the rocky tide pools of Conero Riviera (western Adriatic Sea)

Rocky tide pools are transition environments whose communities are affected by sudden temperature, salinity and nutrient fluctuations. Furthermore, these environments are exposed to multiple stressors and can be easily altered by human trampling. In particular, specific studies on rock pool heterobranchs communities are lacking for the Mediterranean Sea. In this study, the community of Heterobranchia (Mollusca: Gastropoda) living in an anthropized rock pools system in western Adriatic (Ancona, Italy) has been investigated and a first checklist of the sea slugs in this urbanized areas is provided. During the four months survey, a total of 452 specimens, belonging to 19 species and 12 families was recorded. Notable findings were the first record of Placida dendritica for the Conero Riviera, and the first records of Doto cervicenigra and Ercolania viridis for the western Adriatic Sea. Identification of trophic categories showed a diversified assemblage in terms of food sources mirroring a surprising species diversity. Moreover, we provide here the description of a peculiar behavior possibly used by sea slugs to cope with the stressful conditions within this semi-closed system.

Automated summary

Rocky tide pools are transitional environments that are affected by temperature, salinity, and nutrient fluctuations, as well as human disturbances. This study investigated the Heterobranchia (Mollusca: Gastropoda) community in an anthropized rock pool system in Ancona, Italy and provided a checklist of sea slugs in this urbanized area. A total of 452 specimens, belonging to 19 species and 12 families, were recorded during the four-month survey. Notable findings include the first record of Placida dendritica in the Conero Riviera, and the first records of Doto cervicenigra and Ercolania viridis in the western Adriatic Sea. The study also revealed a diverse assemblage in terms of trophic categories, reflecting surprising species diversity. Additionally, a peculiar behavior possibly used by sea slugs to cope with the stressful conditions within this semi-closed system is described.