Figure 1
Sampling sites: (1) the Gulf of Gdańsk, (2) the Vistula Lagoon and (3) the Tagus Estuary (geographic data source: ESRI)
Table 1
The number of individuals and carapace width (mean ± SD) of E. sinensis females and males collected from the Gulf of Gdańsk, the Vistula Lagoon and the Tagus Estuary. The same letters indicate no significant differences (Wilcoxon matched pair test; p > 0.05)
| Site | Number of individuals | Carapace width (mm) | |
|---|---|---|---|
| Average | Range | ||
| Gulf of Gdańsk | 49 | 62.00 ±7.80 | 43.00–82.00 |
| Females | 20 | 61.26 ± 7.90a | 46.90–82.00 |
| Males | 29 | 62.29 ± 7.75a | 43.00–78.60 |
| Vistula Lagoon | 200 | 66.77 ± 8.38 | 33.26–89.07 |
| Females | 89 | 67.04 ± 6.38b | 53.70–81.49 |
| Males | 111 | 66.56 ± 9.22b | 33.26–89.07 |
| Tagus Estuary | 38 | 44.35 ± 6.27 | 20.63–56.42 |
| Females | 21 | 43.88 ± 7.29c | 20.63–44.53 |
| Males | 17 | 44.93 ± 4.87c | 37.83–56.42 |
Figure 2
Percentage of individuals with filled and empty stomachs from the Gulf of Gdańsk, the Vistula Lagoon and the Tagus Estuary
Figure 3
Percentage of females and males from the Gulf of Gdańsk, the Vistula Lagoon and the Tagus Estuary with stomachs containing different categories of food remains. Specimens with empty stomachs are not included; n indicates the number of specimens with filled stomachs (a single crab can contain remains belonging to different categories)
Table 2
The number of specimens with different food remains in their stomachs collected in the Gulf of Gdańsk, the Vistula Lagoon and the Tagus Estuary. Not all remains were taxonomically identified (ni – not identified)
| Gulf of Gdańsk | Vistula Lagoon | Tagus Estuary | |
|---|---|---|---|
| Plant origin | 6 | 133 | 33 |
| Chlorophyta | 6 | 16 | ni |
| Tracheophyta | 0 | 50 | ni |
| No taxonomic identification | 0 | 67 | 33 |
| Animal origin | 25 | 57 | 13 |
| Crustacea | 4 | 1 | ni |
| Bivalvia | 16 | 29 | ni |
| Amphipoda | 3 | 2 | ni |
| Gastropoda | 2 | 1 | ni |
| Polychaeta | 0 | 5 | ni |
| No taxonomic identification | 0 | 16 | 13 |
| Detritus | 5 | 28 | 0 |