Large valves of Brachysira styriaca are easily distinguished from other Brachysira species by the apically elongate central area with a median constriction. Small valves of B. styriaca may be distinguished from other species by a combination of valve shape and size, shape of the central area, striae count, and by its association with larger valves of B. styriaca.

LM scalebar = 10 µm
Brachysira styriaca LM1 Brachysira styriaca LM2 Brachysira styriaca LM3 Brachysira styriaca LM4 Brachysira styriaca LM5 Brachysira styriaca LM6 Brachysira styriaca LM7
Length Range
15.5-36.6 µm
Width Range
4.9-7.1 µm
Striae in 10 µm

Brachysira arctoborealis

Wolfe and Kling 2001

Brachysira arctoborealis LM1 Brachysira arctoborealis LM2 Brachysira arctoborealis LM3 Brachysira arctoborealis LM4 Brachysira arctoborealis LM5 Brachysira arctoborealis LM6
Length Range
21.7-48.2 µm
Width Range
7.2-12.1 µm
Striae in 10 µm

Brachysira brebissonii

R.Ross in B.Hartley 1986

Brachysira brebissonii LM7 Brachysira brebissonii LM6 Brachysira brebissonii LM5 Brachysira brebissonii LM4 Brachysira brebissonii LM3 Brachysira brebissonii LM2 Brachysira brebissonii LM1
Length Range
11-36 µm
Width Range
4-8 µm
Striae in 10 µm

Brachysira hannae

(Reimer) Lange-Bert. and Moser 1994

Brachysira hannae LM1 Brachysira hannae LM2 Brachysira hannae LM Brachysira hannae LM5 Brachysira hannae LM4
Length Range
30-60 µm
Width Range
14-19 µm
Striae in 10 µm

Also compare to

Brachysira lehmanniae

Lange-Bert. and Gerd Moser 1994