Table 1
Water temperature, salinity, sampling method, and characteristics of round goby N. melanostomus in sampling sites collected from Croatia, Slovakia, Poland, and Finland.
| Country | Sampling site | Sampling method | N (male/female) | Median TL [mm] (IQR) | Water temperature [°C] | Salinity [PSU] |
|---|---|---|---|---|---|---|
| Croatia | Sava River | EF | 19 (8/11) | 97 (85–116) | 13 | 0.18 |
| Slovakia | Danube River | EF | 19 (5/14) | 76 (67–87) | 12 | 0.16 |
| Poland | Radunia River | EF | 32 (16/16) | 96 (87–111) | 16 | 0.18 |
| Finland | Coastal area of Helsinki, Baltic Sea | ANG | 26 (13/13) | 117 (102–130) | 9 | 4.33 |
Figure 1
Boxplots comparing the scale cortisol concentration of round goby N. melanostomus (A) sampled in Croatia, Finland, Poland, and Slovakia; (B) using EF and ANG. Boxplots display the median (bold line), IQR (box edges), and whiskers extending to the most extreme values within 1.5 × IQR. Individual data points are shown as jittered dots. ANG, angling; EF, electrofishing; IQR, interquartile range.
Figure 2
Results of gamma GLM model of scale cortisol concentration of round goby N. melanostomus as a function of sampling method (EF, ANG) with TL as covariate. ANG, angling; EF, electrofishing; GLM, Generalised Linear Model; TL, total length.
Table 2
Summary of gamma GLM to model the scale cortisol of round goby N. melanostomus as a function of sampling method (EF/ANG) with TL as covariate.
| Model parameter | Estimate | SE | p |
|---|---|---|---|
| Intercept | 3.095 | 0.418 | 0.001 |
| Sampling method (electrofishing) | 0.545 | 0.184 | 0.004 |
| TL | −0.008 | 0.003 | 0.015 |
Supplementary Table 1
Results of Dunn’s post hoc tests for differences in TL (millimetre) of round goby Neogobius melanostomus from Croatia, Slovakia, Poland, and Finland.
| Country | Z | p |
|---|---|---|
| Croatia − Finland | −2.75 | 0.007 |
| Croatia − Poland | 0.21 | 0.836 |
| Finland − Poland | 3.37 | 0.002 |
| Croatia − Slovakia | 2.86 | 0.006 |
| Finland − Slovakia | 5.83 | <0.001 |
| Poland − Slovakia | 2.30 | 0.005 |
Supplementary Table 2
Results of Dunn’s post hoc tests for differences in the scale cortisol (pg · mg−1) of round goby N. melanostomus from Croatia, Slovakia, Poland, and Finland.
| Country | Z | p |
|---|---|---|
| Croatia − Finland | 3.47 | 0.002 |
| Croatia − Poland | 0.23 | 0.818 |
| Finland − Poland | −3.71 | 0.001 |
| Croatia − Slovakia | 1.00 | 0.479 |
| Finland − Slovakia | −2.39 | 0.033 |
| Poland − Slovakia | 0.86 | 0.451 |