Invasion
Invasion Description
1st Record: France/Basin of Arcachon, Bay of Biscay (1980, http://www.ifremer.fr/docelec/notice/2006/notice2218-EN.htm); Spain/Atlantic Ocean (1980, Cigarria et al. 1997)
Geographic Extent
France/Basin of Arcachon, Bay of Biscay (http://www.ifremer.fr/docelec/notice/2006/notice2218-EN.htm; Queiros et al. 2011); Lisbon/Portugal/Tagus estuary (1984, Moura et al. 2017, abundant, rappid growth); Galicia/Spain/Eo Estuary (1980, Cigarria et al. 1997); Spain/San Simon bay (Ría de Vigo) (Hurtado et al. 2010); Galica/Spain/Ria Arousa (Galil et al. 2013); Lisbon area/Portugal/Tagus estuary (2000, Brito et al. 2015)
Vectors
| Level | Vector |
|---|---|
| Probable | Fisheries Intentional |
Regional Impacts
| Ecological Impact | Habitat Change | |
| In the Basin of Arcachon, France, R. philippinarum, was the third most important species contributing to bioturbation of sediments (Queiros et al. 2011). | ||
| Ecological Impact | Hybridization | |
| Of 328 'Venerupis' spp. sampled in the Ria de Vigo, Spain, nine were apparent hybrids, based on DNA sequences and chromosome studies. The spawning seasons of these two bivalves partially overlap and the chromosomes of hybrids appear to pair normally (Hurtado et al. 2011). However, the frequency and significance of genetic exchange between the species is not known. | ||
| Economic Impact | Fisheries | |
| In French waters, hatchery stocks of R. philippinarum were established in 1972, and a commercial fishery was established by 1984. By 1992, it was sustained by natural breeding, although adversely affected by Vibrio infections. The harvested clams were mostly exported to Spain (Flaasch and LeBorgne 1992). In Spain, culture of this clam began in 1980 (Cigarria et al. 1997). A fishery for R. philippinarum in the Ria Arousa, Spain, has been proposed to be certified as environmentally sustainable by the Marine Stewardship Council, Spain, a designation which is disputed by Galil et al. (2013). | ||
| Ecological Impact | Parasite/Predator Vector | |
| In the Eo estuary, Spain, R. philippinarum has suffered mortality due to protozoan parasites of the genus Perkinsus (Cigarria et al. 1997). The parasites appear to be native to the Northwest Pacific, and introduced to European waters. At least two species, P. olseni and P. honshuesis, are known from Asian R. philippinarum (Elston et al. 2003; Dungan and Reece 2006). | ||
| Ecological Impact | Competition | |
| Ruditapes philippinarum is considered a potential competitor of the native Venerupis decussatus, but the two species differ somewhat in their ecological preferences, with R. philippinarum being more abundant in regions of less sand, slower current, ande higher organic content (Bidegain et al. 2015). In the Tagus estuary, Portugal, the growth performance of R. philippinarum was much higher than that of V. decussatus, whise population is delining (Moura et al. 2017). | ||
| Ecological Impact | Herbivory | |
| Brito et al. (2015) have attributed a decrease in phytoplankton abundance and average size, in the Tagus estuary, Portugal, to development of a large biomass of R. philippinarum. They estimate that R. philippinarum could clear the water column in 10 days (Brito et al. 2015). | ||