Achnanthidium macrocephalum (Hustedt) Round & Bukhtiyarova (1996: 349)

Amaral, Mailor Wellinton Wedig, Medeiros, Gabriela, Daufenbach, Vanessa, Sampaio, Silvio Cesar, Reis, Ralpho Rinaldo Dos, Ludwig, Thelma Alvim Veiga & Bueno, Norma Catarina, 2024, Taxonomy of epilithic diatoms and teratological forms under the presence of metals in surface sediment, Phytotaxa 647 (3), pp. 237-273 : 250

Achnanthidium macrocephalum (Hustedt) Round & Bukhtiyarova (1996: 349)

Figs 7 : L–P

Length: 8.7–13.2 µm; width: 2.7–2.9 µm (n = 6)

Teratological form: deformed valve outline, usually with constriction near the apices.

Occurrence: S3, S4, S8.

Ecological characteristics: Cond.: 22.00–64.00 µS cm –1; BOD: 1.49–4.57 mg L− 1; COD: 5.53–18.10 mg L− 1; N-NH: 130–378 µg L− 1; 3 − 1 − 1 − − 1 − 1 NO: 0.37–2.20 mg L; DO: 7.71–19.35 mg L; pH: 5.51–6.19; PO: 0.006 –0.046 mg L; TP: 0.010 –0.060 mg L; TS: 4.00– 3 4 104.00 mg L− 1; Temp.: 17.37–23.00 °C; Turb.: 6.38–10.70; Flow: 0.44–1.20 m 3 s; Average depth: 0.09–0.34 m; Prec.: 2.73–9.96 mm.

Metal concentrations: Co: 23.91–60.76 mg L –1; Cr: 23.67–88.85 mg L –1; Cu: 163.45–241.67 mg L- 1; Mn: 393.75–557.50 mg L –1; Ni: 31.80–69.89 mg L –1; Pb: 35.58–48.63 mg L –1; Zn: 83.42–173.12 mg L –1.

Figures

FIGURE 7. Epilithic diatoms from Cascavel River micro-watershed in LM. A. Placoneis elginensis. B. P. hambergii. C. P. undulata. D. Achnanthes inflata. E–G. Achnanthidium caledonicum. H–P. A. macrocephalum. L–P. Teratological valves. Q–T. A. tropicocatenatum. U–AC. A. minutissimum. X–AC. Teratological valves. AD–AH. A. modestiforme. AF–AH. Teratological valves. AI–AJ. Gogorevia constricta. AK. Planothidium bagualensis. AL. P. lagerheimii. AM–AP. P. rostratum. AO–AP. Teratological valves. AQ–AR. P. frequentissimum. AS–AT. Psammothidium hustedtii. AU–AV. Humidophila arcuatoides. AW. H. implicata. AX–AZ. H. contenta. AAA– AAC. H. subtropica. AAD. Cocconeis fluviatilis. AAE. C. lineata. AAF. Luticola ectorii. AAG. L. hustedtii. AAH. L. charlatii. AAI– AAJ. L. permuticoides. AAK. L. ventricosa. AAL–AAN. L. goeppertiana. Scale bars: 10 µm.