Table 4. Statistical analyses of stable isotope signatures of gastropod food source types.
| Dependant variable | Source | df | MS | F | p |
| δ13C | Food×Location | 6 | 17.079 | 4.381 | <0.05 |
| Error | 48 | 3.899 | |||
| Food×Time | 6 | 16.138 | 5.519 | <0.05 | |
| Error | 24 | 2.924 | |||
| δ15N | Food×Location | 6 | 4.659 | 1.477 | ns |
| Error | 48 | 3.155 | |||
| Food×Time | 6 | 8.881 | 6.356 | <0.001 | |
| Error | 24 | 1.397 |
Two-way ANOVA for δ13C and δ15N, including microphytobenthos, detritus, Cladophora sp. and sedimentary organic matter (different food source types) collected at Catalina Bay, Lake Sibaya and Lake Nhlange (different locations in Maputaland), and collected in 2007, 2009 and 2010 at Catalina Bay (different times).