Sellaphora subbacillum, S. ventraloides and S. aggerica are similar in size, stria density, and the presence of grooves that are visible in LM. Sellaphora ventraloides has a more lanceolate valve outline and bow-tie-shaped central area. The valve ends of S. subbacillum and S. aggerica are broadly rounded - never subcapitate. The stria density is slightly higher in S. subbacillum and S. aggerica.

LM scalebar = 10 µm
Sellaphora stroemii LM2 Sellaphora stroemii LM5 Sellaphora stroemii LM6 Sellaphora stroemii LM1 Sellaphora stroemii LM7 Sellaphora stroemii LM4 Sellaphora stroemii LM3
Length Range
6-21 µm
Width Range
3.5-5.0 µm
Striae in 10 µm

Sellaphora subbacillum

(Hust.) Falasco and Ector 2009

Sellaphora subbacillum LM2 Sellaphora subbacillum LM1 Sellaphora subbacillum LM3 Sellaphora subbacillum LM7 Sellaphora subbacillum LM4 Sellaphora subbacillum LM6 Sellaphora subbacillum LM5
Length Range
7-21 µm
Width Range
4-5 µm
Striae in 10 µm

Also compare to

Sellaphora ventraloides

(Hust.) Falasco and Ector

Sellaphora aggerica

(E. Reichardt) Falasco and Ector