Table 4 Formulas of rotifer trophic state index (TSI_ROT).

Rotifer numbers (N, ind. L^− 1)

TSI_N = 5.38 Ln(N) + 19.28

Total biomass (B, mg w.wt. L^− 1)

TSI_B = 5.63 Ln(B) + 64.47

Percentage of bacterivores in total numbers (BAC, %)

TSI_Bac = 0.23 BAC + 44.30

Ratio of biomass to numbers (B: N, mg w.wt. ind. ^–1)

TSI_B/N = 3.85 (B: N)^−0.318

Percentage of species indicative of high trophy in the indicative group’s numbers (IHT, %)

TSI_IHT = 0.203 IHT + 40.0

Rotifer Trophic State Index (TSI_ROT) is the mean of the calculated indices