Fig. 6.

Partial RDA biplot showing snail species found in the study sites and their correlation with environmental parameters of zone I and zone III. For zone I, the explanatory variables explained 43 % of the variation in species composition, while the first and second axes display 82 and 14 % of this variation, respectively. For zone III, the explanatory variables explained 41 % of the variation in species composition, while the first and second axes display 52 and 21 % of this variation, respectively. Key: Nitr nitrates, EC electric conductivity, TDS total dissolved solids, CoW cobalt in water, Calc calcium, ORP oxygen reduction potential, Temp temperature, Turb turbidity, MPhyt macrophytes