| Main Ref. | Gollasch, S. and S. Nehring, 2006 |
| To | Baltic Sea. |
| FAO area | Atlantic, Northeast |
| From | Northwest Atlantic. |
| FAO area | Atlantic, Northwest |
| Year | 1200 |
| Range | |
| Period | Pre 18th century |
| Established in the Wild | Unknown |
| Established in Aquaculture | |
| Significant Ecological Interactions | probably yes - adverse |
| Significant Socio-economic Effects | |
| Introduced by | |
| Reason | accidental with ships |
| Other Reason | |
| Comments | Introduced in Baltic and North Seas before 1200 and in Inland waters of Germany in 1931. |