Fragilaria tenera var. nanana (Lange-Bertalot) Lange-Bertalot & S.Ulrich (2014: 7)

* Fragilaria tenera var. nanana (Lange-Bertalot) Lange-Bertalot & S.Ulrich (2014: 7)

Figs 3 View FIGURE 3 : AL–AO

Length: 45.1–67.1 µm; width: 1.9–3.1 µm; striae: 20–22 in 10 µm (n = 30)

Taxonomical remarks: the individuals from Cascavel river micro-watershed contain a higher striae number (18.5–20 in 10 µm) than the original description. However, the authors pointed out that their specimens had lower striae density compared to the protologue provided by Meister ( Lange-Bertalot & Ulrich 2014).

Teratological form: deformed valve outline, undulated.

Figs 3 View FIGURE 3 : AN–AO

Length: 45.1–54 µm; width: 2.1–2.5 µm; striae: 21–22 in 10 µm (n = 3)

Occurrence: S3.

Ecological characteristics: Cond.: 38.00–40.00 µS cm –1; BOD: 1.49–3.27 mg L− 1; COD: 7.23–8.08 mg L− 1; N-NH: 316–378 µg L− 1; 3 −1 −1 − −1 −1 NO: 0.37 mg L; DO: 11.42–14.57 mg L; pH: 5.79–6.19; PO: 0.006 –0.008 mg L; TP: 0.010 –0.017 mg L; TS: 38.00–66.00 3 4 mg L− 1; Temp.: 17.37–17.50 °C; Turb.: 7.03–10.70; Flow: 0.47 m 3 s; Average depth: 0.19–0.23 m; Prec.: 9.96 mm.

Metal concentrations: Co: 23.91–33.57 mg L –1; Cr: 27.33–78.86 mg L –1; Cu: 197.55–235.49 mg L –1; Mn: 398.50–444.52 mg L –1; Ni: 31.80–69.89; Pb: 35.58–46.56 mg L –1; Zn: 93.81–167.31 mg L –1.