Patella ferruginea is the most threatened macroinvertebrate in the western Mediterranean, where it is at serious risk of extinction. There is little information on the status of the various populations and most data were published more than 25 years ago. This study provides updated information on the global status of this species, and implications for management and conservation, and tests the hypothesis that population structure can be influenced by collection by people and by the type of substrate. Fifty-five localities were surveyed in Corsica, Sardinia, Tuscany and Sicily, on the islands of Egadi and Pantelleria, and on the Zembra archipelago and Tunisian coasts. The species is extinct on mainland Italy and Sicily but isolated individuals can be found on Egadi and Pantelleria. Populations on Corsica and Sardinia have declined dramatically during the last 25 years. The population in the Zembra archipelago is well preserved, although more widely on Tunisian coasts the species is highly threatened. The information provided here, combined with information from the literature, indicates a strong decline and/or extinction of many populations throughout the western Mediterranean and the presence of healthy populations only in some locations along the north African coast. The species exhibits an increase in density and mean size in areas free of human pressure but the type of substrate (natural or artificial) has no strong influence.

The population of the endangered limpet Patella ferruginea in the Peñón de Vélez de la Gomera, a small Spanish peninsula located on the North African coast (south-west Mediterranean) was evaluated by surveys carried out in June and October 2012. Overall, 567 specimens were recorded along the entire coastline (about 1320 m) of this enclave (169 individuals measured >30 mm in maximum diameter of the shell, likely adults, and 398 specimens were <30 mm, likely immature individuals). In this site an average 0.13 adults/m was registered, and the maximum density observed was 0.90 adults/m in some zones. This points out the importance of this enclave among the present known populations existing in Spanish territories of this highly endangered limpet, but particularly highlights the role of the adjacent North African coastal protected areas in the conservation of this species.

Patella ferruginea is a highly endangered species and the knowledge of its reproductive strategy is essential for suitable management and conservation. In this context, its strategy remained unclear and several authors argued that the species could be gonochorist. The evidence of length specific sex ratios in the sense of protandrous strategy has been confirmed by direct observation of sex change in the species.

The mollusc Patella ferruginea, endemic to the Mediterranean, is presently in serious risk of extinction. Although the species was formerly distributed in the western Mediterranean Basin, today its Mediterranean range has contracted to a few restricted areas. This paper reports on the finding of a range extension of the historical distribution of this species in the Iberian Peninsula. The implication of the Marine Protected Areas (MPAs) effect is discussed.