Figure 1
Figure 2
Figure 3
Morphometric characteristics of Rapana venosa used in experimental cages (Snake Island, north-western Black Sea, Ukraine)
| N | Size class, mm | n | Shell height (SH), mm | Total mass (WR), g | ||
|---|---|---|---|---|---|---|
| min. − max | SH means ± SE | min. – max | WR means ± SE | |||
| 1 | 30–40 | 20 | 34.5–44.7 | 40.7* ± 0.56 | 6.17–13.69 | 10.19 ± 0.44 |
| 2 | 41–50 | 18 | 42.1–50.4 | 46.48 ± 0.51 | 14.15–25.48 | 18.46 ± 0.77 |
| 3 | 60–70 | 10 | 61.3–67.0 | 64.44 ± 0.64 | 41.93–63.20 | 53.13 ± 2.28 |
| 4 | 80–90 | 10 | 80.6–85.1 | 83.46 ± 0.43 | 100.33–136.31 | 118.33 ± 3.69 |
Quantity (in %) of mussels consumed, by shell size
| Mussels shell length (mm) | Shell height of Rapana venosa (mm) | ||||
|---|---|---|---|---|---|
| 30–40 | 41–50 | 60–70 | 80–90 | ||
| 0–10 | 5.7 | – | – | – | |
| 10–20 | 10.76 | 10.20 | 6.57 | 3.73 | |
| 20–30 | 63.29 | 61.22 | 41.61 | 20.90 | |
| 30–40 | 14.56 | 19.73 | 32.85 | 31.34 | |
| 40–50 | 5.06 | 6.12 | 14.60 | 32.09 | |
| 50–60 | 0.63 | 2.72 | 4.38 | 11.94 | |
| Number of mussels | eaten | 158 | 147 | 137 | 134 |
| total | 468 | 666 | 573 | 560 | |
Regression coefficients of the size/mass ratio for mussels near Snake Island, based on feeding experiments in the north-western Black Sea
| Regression | Parameters | SE a | SE b | R2 (%) | |
|---|---|---|---|---|---|
| a | b | ||||
| lnW=a+blnL | –8.955 | 2.917 | 0.093 | 0.027 | 99.8 |
| lnWw=a+blnL | –10.588 | 2.905 | 0.180 | 0.050 | 99.3 |
| lnWst=a+blnL | –9.345 | 2.782 | 0.119 | 0.034 | 99.7 |
Size and mass characteristics of the Mediterranean mussel (Mytilus galloprovincialis) consumed in experiment (Snake Island, north-western Black Sea, Ukraine
| Parameters | Shell height (SH) Rapana venosa, mm | ||||
|---|---|---|---|---|---|
| 30–40 | 40–50 | 60–70 | 80–90 | ||
| Lmussel, mm | min.–max | 2.6–52.5 | 12.3–58.3 | 14.1–51.9 | 17.9–59.6 |
| WM.gal, g | min.–max | 0.002–13.43 | 0.194–18.237 | 0.29–12.991 | 0.582 –19.440 |
| WwM.gal, g | min.–max | 0.001–2.509 | 0.037–3.402 | 0.055–2.427 | 0.110–3.627 |
| WsM.gal, g | min.–max | 0.001–5.321 | 0.094–7.123 | 0.137–5.154 | 0.267–7.573 |
| Mussel shell mass | 0.428 | 0.557 | 1.248 | 1.995 | |
| Feeding intensity | 99 | 72 | 57 | 41 | |
| Daily ration | 0.189 | 0.249 | 0.563 | 0.917 | |
Morphometric characteristics of the Mediterranean mussels (Mytilus galloprovincialis) used in the experimental cages (Snake Island, north-western Black Sea, Ukraine)
| N | n | Length (L), mm | Total mass (Wmussel), g | ||
|---|---|---|---|---|---|
| min.–max | L means ± SE | min.–max | Wmussel means ± SE | ||
| 1 | 468 | 2.6–62.8 | 24.85 ± 0.41 | 0.002–22.67 | 2.09 ± 0.106 |
| 2 | 666 | 5.3–60.0 | 24.96 ± 0.33 | 0.017–19.85 | 2.07 ± 0.091 |
| 3 | 573 | 5.1–53.3 | 26.60 ± 0.40 | 0.015–14.05 | 2.55 ± 0.114 |
| 4 | 560 | 6.2–60.5 | 28.49 ± 0.49 | 0.026–20.34 | 3.378 ± 0.153 |