Diversity and distribuition of patellid limpets along the southwestern African coast (Benguela current)

• Main Author: Carneiro, Ana Pinto
• Other Authors: Serrão, Ester, Neiva, João
• Format: Master Thesis
• Language: English
• Published: 2021
• Subjects: Patellogastropoda; DNA barcoding; True limpets; Philogeny; Domínio/Área Científica::Ciências Naturais::Outras Ciências Naturais; North Atlantic; Northeast Atlantic
• Online Access: http://hdl.handle.net/10400.1/17471

Limpets are keystone species on the intertidal communities because of their constant grazing, but their diversity and taxonomy are poorly assessed, particularly along the African shores. In this study specimens of the Patellidae family collected along the southwestern coast of Africa and from north Atlantic were barcoded for the mitochondrial gene cytochrome c oxidase subunit I (COI). Genetic data and literature surveys were used to generate distribution maps of the identified species, to understand the range of each species within these regions. Phylogenetic analyses based on available GenBank sequences were also conducted to further explore species relationships. From the samples collected, 72 DNA sequences were obtained, of which 9 different species of the family Patellidae were identified. At least one species of each genus was recognized, in addition to 2 Siphonariidae and 1 Fissurellidae limpets. Patella was only found in the North Atlantic. Cymbula and Helcion were restricted to Southern Africa, with Cymbula safiana being the only species with a distribution reaching north of Africa. Only one Scutellastra was identified in Africa, but we cannot confirm through genetic data its widest distribution, documented to reach from South Africa to Australia. Multivariate analysis showed important regional differences in species composition along the Eastern Atlantic coast. Three different groups were recognized: 1) South Africa and Namibia; 2) Angola and Tropical Africa; and 3) Northeast Atlantic and Mediterranean Sea. Phylogenetic analyses are in line with previous studies. Patella genus forming a well-supported clade, with Cymbula and Helcion sharing the same branch as sister taxa, and Scutellastra subdivided in paraphyletic biogeographic lineages. One lineage formed a clade with Cymbula and Helcion. We can conclude that are still needed a revision on the taxonomy and distribution of the Patellidae family, particularly on the African coasts. As lapas da ordem Patellogastropoda, ou verdadeiras lapas, são ...