Academic Journals Database
Disseminating quality controlled scientific knowledge

Conservation status and updated census of Patella ferruginea (Gastropoda, Patellidae) in Ceuta: distribution patterns and new evidence of the effects of environmental parameters on population structure

Author(s): Rivera–Ingraham, G. A. | Espinosa, F. | García–Gómez, J. C.

Journal: Animal Biodiversity and Conservation
ISSN 1578-665X

Volume: 34;
Issue: 1;
Start page: 83;
Date: 2011;
VIEW PDF   PDF DOWNLOAD PDF   Download PDF Original page

Keywords: Limpet | Patella ferruginea | Endangered species | Conservation | Substrate roughness | Strait of Gibraltar | Ceuta

The Strait of Gibraltar has important populations of the highly endangered patellid limpet Patella ferruginea. Between 2006 and 2010, an exhaustive census was carried out in Ceuta. The total coastline was divided into 17 sectors. The coast of each sector was examined by using 10 m transects. For the case of those sectors composed of breakwaters, jetties or islets, no transects were used, and instead, the total number of individuals was recorded. Each individual was measured to the nearest millimetre using a calliper. Moreover, the complete rocky shore length where the species could potentially be present was calculated, and an estimation of the total number of individuals that each sector could host was made. Results indicate that Ceuta could be home to around 44,000 individuals. The species found in Point Benzú, its westernmost limit of distribution on the North African coasts. The largest populations were recorded on the South Bay, with higher Mediterranean influence. Our results indicate that substrate roughness (topographic heterogeneity) and the area’s accessibility highly influence the abundance and population structure. Those populations located on high topographic heterogeneity substrates show higher recruitment rates and lower percentages of larger individuals, while medium to low rugosity surfaces presented the opposite pattern. Additionally, easily accessible areas (and frequented by humans) presented smaller average shell sizes. Implications of the results for conservation purposes are discussed.

Tango Jona
Tangokurs Rapperswil-Jona

     Affiliate Program