TABLE 3.
Conceptual summary table containing the main results obtained with different methodological approaches for sardinella (Sardinella aurita), anchovy (Engraulis encrasicolus), and sardine (Sardina pilchardus)
| Methodological approach | Variable | Species | ||
|---|---|---|---|---|
| S. aurita | E. encrasicolus | S. pilchardus | ||
|
Stable isotopes δ13C and δ15N |
δ13C–TL relationship | Positive a | Positive a | (ns) |
| δ15N–TL relationship | (ns) | (ns) | Negative a | |
| Isotopic niche area | Widest 0.46‰2 | 0.21‰2 | 0.38‰2 | |
| Isotopic niche overlap | S. aurita–E. encrasicolus > S. aurita–S. pilchardus | |||
| Stomach contents (visual analysis) | SFD–TL relationship | Positive a | Negative a | Negative a |
| Parasites | Highest | Lowest | ||
| Anthropogenic pollution | Highest | Lowest | ||
| Stomach contents corrected by DNA metabarcoding | Prey number (main contribution) | euph./decap./malac. (highest abundance) | euph./decap./malac. | cal.cop./euph. |
| Prey biomass (main contribution) | euph./decap./malac. | euph./decap./malac. | euph./decap./malac. | |
| Shannon diversity index | 2.31 | 1.51 | 1.84 | |
| PPSR | >75% large prey | ~60% large prey | >75% large prey | |
| PPBR | >80% large prey | ~60% large prey | >75% large prey | |
| Relative diet dissimilarity | Highest difference in jelly/siph. | Highest RDI between E. Encrasicolus–S. pilchardus | ||
| Beta‐diversity | Lowest individual variation in prey composition | Most different due to higher prey replacement (turnover) | ||
| Similar nestedness in the three species | ||||
a
Denotes significant difference (p < .01); ns means not significant relationship; “cal.cop.”: calanoid copepods; “euph.”: euphausiids; “decap.”: decapods; “malac.”: malacostracans; “jelly”: jelly organisms; “siph.”: siphonophores.