Figure legends
Figure 1. Relationships between the zebrafish eDNA concentration and the number of fish individuals among filter pore sizes and fragment lengths. From left to right, each four-panel shows the relationships using larger (10 µm) to smaller (0.2 µm) pore size filters. Additionally, each four-panel reveals the relationships targeting shorter (132 bp) to longer (1021 bp) eDNA fragments from the top to bottom. Solid and dashed lines represent the linear regressions of target eDNA concentrations (log-transformed) against fish individuals and their 95% confidence intervals (CIs). The abbreviation “Adj.R2” meansR2 values adjusted by the degree of freedom.
Figure 2. R2 values (a) and slopes (b) in the linear regressions for zebrafish eDNA among filter pore sizes and fragment lengths. Each color of the bar plots (a) and plots (b) indicate the filter pore size. Plots and error bars in (b) represent the mean values and their 95% CIs.
Figure 3. Relative R2 values among eDNA size fractions targeting the size-fractionated (CX, a), upside-cumulative (UCX, b), and downside-cumulative eDNA concentration (DCX, c) from Japanese jack mackerel. Each relative R2 value is calculated based on the eDNA concentration at >10 µm (a & b) and >0.4 µm size fractions (c). Plots and error bars represent the mean relativeR2 values and 95% CIs. Gray dashed lines represent the standard R2 values (relativeR2 value = 1). All the datasets originated from Jo et al. (2019).
Figure 4. Schematic depiction of the relationship between eDNA concentration and species abundance depending on the eDNA particle size inferred by this study. As the particle size of the target eDNA increases, its apparent persistence in water could be shorter, whereas its spatial dispersion and distribution could be more heterogeneous. Thus, larger eDNA particles would not necessarily explain the abundance of target species more accurately and sensitively. However, considering the multiple factors regarding the eDNA characteristics and dynamics, “appropriately” larger eDNA particles (indicated as 3–10 µm in our study) can be suitable for accurate and sensitive abundance estimation.