Biometric conversion factors as a unifying platform for comparative assessment of invasive freshwater bivalves

Invasive bivalves continue to spread and negatively impact freshwater ecosystems worldwide. As different metrics for body size biomass are frequently used within the literature standardise bivalve-related ecological impacts (e.g. respiration filtration rates), lack of broadly applicable conversion equations currently hinders reliable comparison across bivalve populations. To facilitate improved comparative assessment among studies originating from disparate geographical locations, we report six invasive (or species complex members) worldwide: Corbicula fluminea, C. largillierti, Dreissena bugensis, D. polymorpha, Limnoperna fortunei Sinanodonta woodiana, tested reliability (i.e. precision accuracy) these equations. Body (length, width height) living-weight (LW), wet-weight (WW), dry-weight (DW), dry shell-weight (SW), shell free (SFDW) ash-free (AFDW) were collected a total 44 populations located in Asia, Americas Europe. Relationships between individual metrics, as well proportional weight-to-weight factors, determined. For most species, although inherent variation existed sampled populations, directional measurements found be good predictors all length LW, WW, SW or DW: R2 = 0.82–0.96), with moderate high accuracy mean absolute error (MAE): ±9.14%–24.19%. Similarly, narrow 95% confidence limits low MAE observed relationships, indicating calculated factors LW AFDW; CI range: 0.7–2.0, MAE: ±0.7%–2.0%). Synthesis applications. Our derived prediction can rapidly estimate biologically active assessed based on simpler wide range situations globally. This allows calculation approximate average indicators that, when combined density data, per unit-area contribute quantification population-level effects. These general will support meta-analyses, allow historic contemporary data. Overall, enable conservation managers better understand predict bivalves.