Navicula cryptocephala Kützing (1844: 95)

Figs 10: G–I

Length: 19.9–26.1 µm; width: 4.7–6.9 µm; f striae: 16–18 in 10 μm (n = 3)

Teratological form: deformed valve outline, with loss of transapical symmetry.

Occurrence: S2.

Ecological characteristics: Cond.: 52.00 µS cm –1; BOD: 4.16 mg L− 1; COD: 17.43 mg L− 1; N-NH: 316 µg L− 1; NO: 0.32 mgL−1; DO: 3 3 − 1 − − 1 − 1 − 1 3 14.62 mg L; pH: 6.04; PO: 0.004 mg L; TP: 0.012 mg L; TS: 16.00 mg L; Temp.: 17.90 °C; Turb.: 9.25; Flow: 0.45 m s; 4 Average depth: 0.19 m; Prec.: 9.96 mm.

Metal concentrations: Co: 19.28–23.11 mg L –1; Cr: 25.92–83.62 mg L –1; Cu: 196.71–241.52 mg L- 1; Mn: 400.50–955.89 mg L –1; Ni: 33.21–59.59 mg L –1; Pb: 36.28–38.28 mg L –1; Zn: 78.35–169.95 mg L –1.