| Main Ref. | AquaNIS, 2012 |
| To | Isefjorden |
| FAO area | Atlantic, Northeast |
| From | unknown |
| FAO area | |
| Year | 1935 |
| Range | |
| Period | 1925-1949 |
| Established in the Wild | |
| Established in Aquaculture | |
| Significant Ecological Interactions | |
| Significant Socio-economic Effects | |
| Introduced by | |
| Reason | ballast water |
| Other Reason | |
| Comments | It is recorded from both the Baltic Sea and North Sea sides of Denmark. |