Montana Field Guide

Morphological Category – Symmetric biraphid

Valves linear-lanceolate with parallel or slightly concave margins and short apiculate apices. Pseudoseptum present at each apex. Axial Area very narrow. Central Stauros a transverse rectangle. Raphe filiform with straight and weakly inflated proximal ends. Striae weakly radiate throughout. Areolae closely spaced, 24-30 in 10 µm.

Size Range
Length 25-34 µm. Width 4.7-5.8 µm. Striae in 10 µm 24-30.

Useful Link:
Diatom Glossary [Diatoms of North America website]

Stauroneis prominula is distinguished from S. leguminopsis by its straight, not triundulate, margins and by its transversely rectangular, not bow tie shaped, stauros.

Lakes and sloughs.

Cold, alkaline waters with low nutrients and conductivity.

Diatoms typically reproduce by cell division (mitosis) and occasionally by meiosis—sexual reproduction in which female and male gametes combine to form a specialized zygote called an auxospore. Repeated divisions result in cells of a population becoming progressively smaller and smaller. When cells reach a critically small size, sexual reproduction is initiated, resulting in an auxospore and initial cells that are the largest attainable for the species, after which cell division and size reduction resume (Amato 2010).

Climate change and regional warming.