| Reference no. | Stehmann, M. and D.L. Bürkel, 1984 |
| Ecosystem | North Sea |
| Status | native |
| Abundance | occasional (usually not seen) |
| Lifestage | adults |
| Regional database | |
| Remarks | Southern North Sea (Ref. 52268). Catches in the central and northern North Sea patchy (Ref. 82399). Threats in Skagerrak and Kattegat: bycatch fisheries, eutrophication, habitat loss (Ref. 83294). HELCOM's status of threat : endangered (Ref. 83294). |