Crepipatella dilatata (Lamarck, 1819): routes of introduction of a new invasive alien gastropod species in Portugal

• Autor(a) principal: Santos, Maria Beatriz Gomes dos
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/40533
• topic: Biological invasions; DNA Barcoding; Molecular analysis; Pathways of introduction; Population genetics

In 2019, an alien gastropod of the family Calyptraeidae, was found in Ria de Aveiro (Portugal), associated with natural mussel banks of the genus Mytillus and co-occurring alongside Crepidula fornicata (Linnaeus, 1758), another alien species of the same family. The sequencing of the mitochondrial Cytochrome C Oxidase Subunit I (mtCOI) gene confirmed the identity of the species as Crepipatella dilatata (Lamarck, 1819), never before reported in Portugal. This South American species of slipper snail, native to Chile and Argentina, has a gregarious behaviour and reproductive strategies which make it a successful invader. Human activities are usually responsible for the introduction of alien species outside of their natural ranges, through several vectors and pathways of introduction. In Europe, C. dilatata was observed for the first time in 2005 in Rías Baixas (Galicia, Spain), after being introduced through the importation of Mytillus galloprovincialis (Lamarck, 1819) originating from Chilean mussel beds. In 2021, the number of observations registered in iNaturalist showed an increase of C. dilatata specimens outside of the initial detected site, indicating a dispersal along the Portuguese coast. To understand this species’ invasion in Portugal, specimens were collected from the eight sites with known records to analyse the genetic structure of the population. Haplotype analyses found in Portugal, Spain, Chile, and Argentina suggest various events of introduction either by native populations of South America or by a secondary introduction through the first invaded location in Europe.