Staurosirella sp. 2

Ruwer, Daiane Trevisan & Rodrigues, Liliana, 2021, Sediment diatoms from Upper Paraná River floodplAiN lAKeS: New recordS, Iheringia, Série Botânica (e 2021012) 76, pp. 1-16 : 7

Staurosirella sp. 2

( Figs. 41-46 )

Valves heteropolar, ovate to clavate. Ends rounded, with apices slightly subcapitate and bases attenuate. Axial area linear and narrow, central area absents. Striae parallel and alternated slightly radiate at the ends in some specimens. Length: 5.6 - 15.9 μm; width: 2.1-3.1 μm; striae 10-12 in 10 μm. The specimens documented resemble Pseudostaurosira clavatum Morales ( Morales 2002) in valve morphology. Staurosirella sp. 2 can be distinguished from this taxon by lower values of valve length and less attenuate ends. Staurosirella sp. 2 is similar to species from the Opephora Petit genus concerning valve shape; however, Opephora presents predominant marine habit ( Round et al. 1990).

Material examined: BRAZIL, MATO GROSSO DO SUL: Batayporã, Garças Lake , 21.IX.2017, sediment, D.T. Ruwer (Nupélia UEM - 18085-18097 ) .

Figures

Figure 41-65. Sediment diatoms from subtropical floodplain lakes (LM).41-46. Staurosirella sp. 2; 47-49. Eunotia deficiens; 50-52. Eunotia formica; 53. Eunotia bilunaris; 54-58. Eunotia deformis; 59-61. Eunotia longicamelus; 62-65. Eunotia monodon. (Scale bar: 10 μm).