Distribution of Mytilopsis leucophaeata cochleata (A, B), Dreissena polymorpha (C, D) in the Netherlands (Source NDFF service team, Nijmegen). A, C. All records in the period 1800–2024 are indicated with blue squares. B, D. All records in the period 1990–2024 are indicated with red dots; atlas blocks without records in this period but with records before 1990 are indicated with blue squares. A small atlas block measures 5 × 5 km, a large atlas block 10 × 5 km covering two topographical map sheets (east and west). Soil type is indicated by different colours: orange: loess, yellow: sand, purple: peat, green: clay (Vogelbescherming Nederland 2007).

 
 
  Part of: van der Gaag M, van der Velde G, Leuven RSEW (2024) Matching field-based ranges in brackish water gradients with experimentally derived salinity tolerances of Conrad’s false mussel (Mytilopsis leucophaeata cochleata) and zebra mussel (Dreissena polymorpha). Aquatic Invasions 19(2): 169-190. https://doi.org/10.3391/ai.2024.19.2.124566