| Country | Finland | Ecosystem | Baltic Sea |
| Locality | Southeastern Baltic | Depth | 20 m |
| Introduced | Year Intro. | 1995 | |
| Life Stage | not specified | unsexed | |
| Quantitative | 262 | Unit | numbers/m^3 |
| Semi Quantitative | 100-1000 | Unit | numbers/m^3 |
| Qualitative | common | ||
| Year | 1999 - 1999 | Period | 1975-2000 |
| Date | 1999-08-01 00:00:00 - 1999-08-15 00:00:00 | Record Type | field sample |
| Record Type | field sample | ||
| Seasonal | Method | volumetric | |
| Remarks | Population density decreased with increasing depth, water salinity and temperature. | ||