Platessa strelnikovae is easily distinguishable from other relatively large-celled Platessa species, such as P. bavarica, P. montana, P. stewartii and P. hustedtii. Platessa bavarica has a rapheless valve with a very broad, elliptical axial area and a raphe valve with a very narrow, transverse central area. Platessa montana differs by its rhombic-elliptic valve shape with round to rectangular central area on the raphe valve, a narrower, lanceolate axial area on the rapheless valve and higher stria density (18–24 vs. 14–17 in P. strelnikovae). Platessa hustedtii has more parallel valve margins with an elliptic central area on raphe valve and higher stria density (17–22 in 10 μm). Platessa stewartii has narrow axial areas and relatively narrow transverse central areas on both valves. None of the other Platessa species display a horseshoe-shaped depression in the central area of the rapheless valve. This depression makes P. strelnikovae somewhat similar to P. lanceolatum, but the latter has narrow axial area and more distant striae (12–15 in 10 μm).

LM scalebar = 10 µm
Platessa strelnikovae LM6 Platessa strelnikovae LM1 Platessa strelnikovae LM5 Platessa strelnikovae LM4 Platessa strelnikovae LM2 Platessa strelnikovae LM3 Platessa strelnikovae LM7
Length Range
11-19 µm
Width Range
6-7 µm
Striae in 10 µm

Platessa hustedtii

(Krasske) Lange-Bert. in Krammer and Lange-Bert. 2004

Platessa hustedtii LM4 Platessa hustedtii LM3 Platessa hustedtii LM1 Platessa hustedtii LM2 Gs027063  Plhust1 De000026 1 Gc44474  Rup1
Length Range
11-15 µm
Width Range
5.0-6.4 µm
Striae in 10 µm

Platessa stewartii

(R.M.Patrick) Potapova 2012

Platessa stewartii LM7 Platessa stewartii LM1 Platessa stewartii LM2 Platessa stewartii LM5 Platessa stewartii LM4 Platessa stewartii LM3 Platessa stewartii LM1
Length Range
11–16 µm
Width Range
5.7–7.0 µm
Striae in 10 µm

Planothidium lanceolatum

(Bréb. ex Kütz.) Lange-Bert. 1999

De000084 6 De000084 4 De000084 7 Ih042040  Pllanc2 Ih042040  Pllanc4 Ih042040  Pllanc1 Mo000019 1
Length Range
7-24 µm
Width Range
4.5-8.0 µm
Striae in 10 µm

Also compare to

Platessa bavarica

Lange-Bert. and G.Hofm.

Platessa montana

(Krasske) Lange-Bert.