Invasion
Invasion Description
The date of first occurrence of Perna perna on the Brazilian Coast is not known, but its absence in prehistoric coastal shell middens indicates that was introduced after European colonization, probably with the African slave trade in the 17th-19th centuries (Souza et al. 2003; Oliviera et al. 2017). However, C14 dating of shells at archaeological sites produced ages of 700-800 years, predatiing European colonization. Genetic analysis indicated that divergence between Brazilian and South African populations occorred ~200,000 years BP (Pierri et al. 2016). A later study supports the introduced status, and found that the 'pre-colonial' sites with P. perna sites had been disturbed in recent years, and the occurrence of the mussels probably resulted from contamination. Recalibration of the radiocarbon measurements gives dates of 1448-1801, consistent with introduction thorugh the slave trade (Silva et al. 2018).
Geographic Extent
Espiritu Santu state/Brazil/Atlantic Ocean (Siddall 1980; Souza et al. 2003; Silveira et al. 2006); Bahia State/Brazil/Atlantic Ocean (Florida Museum of Natural History 2011)
Vectors
| Level | Vector |
|---|---|
| Alternate | Hull Fouling |
| Alternate | Dry Ballast |
Regional Impacts
| Economic Impact | Fisheries | |
| Perna perna is extensively harvested from wild populations and reared in aquaculture in Brazil (Souza et al. 2003; da Rocha et al. 2007; de Sa et al. 2007). | ||