Sellaphora stroemii, S. ventraloides and S. aggerica are similar in size, shape, stria density, and the presence of grooves that are visible in LM. For all of these taxa, valves at the small end of the size range are so similar that they may not be distinguishable from one another. The stria density is slightly lower and valve ends are often subcapitate in S. stroemii and S. ventraloides. The valves of S. aggerica are more narrow.

LM scalebar = 10 µm
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

Sellaphora stroemii

(Hust.) H.Kobayasi in Mayama et al. 2002

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

Also compare to

Sellaphora ventraloides

(Hust.) Falasco and Ector

Sellaphora aggerica

(E. Reichardt) Falasco and Ector