First record of invasive crab Percnon gibbesi (H. Milne Edwards, 1853) at Pianosa Island: the second goal reached by the innovative Marine Citizen Science Literacy Project "PERCORSI NEL BLU" ("BLUE PATHS").

PERCORSI NEL BLU / BLUE PATHS is an innovative Project of well-integrated Marine Citizen Science Literacy, launched in 2011 by the School Institute ISA 2, in La Spezia - Italy. Since then the Project has set up a Network among schools, citizens, institutions and research centers in coastal monitoring activities. This study highlights how important can be the contribution of Citizen Scientists for collecting new data and information on alien species in Marine Protected Areas (MPAs), representing an opportunity of early-warning system. In October 2019, a Citizen Science coastal monitoring Campaign of the benthos on rocky bottom was carried out by the Team Project at Pianosa Island MPA . n situ observations allowed to record several specimens of P. gibbesi (150 in Autumn, 26 in Winter and 74 in Summer) exclusively in C5, C6, C7 transects and at the bathymetric level of - 0.5m and -1 m (Fig. 3-4), and to gather some useful information, in particular: 1) state of health: evidence of autotomy induced by predators; 2) type of rocky bottom: the absence of burrows, cracks and crevices is the main limitation to its distribution; 3) covering of algal species, leafing and encrusting Rhodophyceae, could probably prevail in the diet (e.g.: Amphiroa rigida, Jania spp., Laurencia spp.); 4) gregarious behaviour; 5) season.