diatomaniac's Identifications

Scale bar = 10 micrometers

Specimens ranged in length from 90 - 99 micrometers. Width was consistently ~14 micrometers. Stria density / 10 micrometers was 19-20. The specimens from this location displayed more pronounced areolae adjacent to the raphe and stauros.

One specimen displayed a lack of areolae outside of the pronounced set adjacent to the raphe and stauros.

scale bar = 10µm

SMM_DIDYMO_1.10a
Kimball River, Cook Co., Minnesota

Valves are very large and contain a headpole (capitate) and footpole (subcapitate and less broad than the headpole). Striae are linear with proximal raphe ends that are inflated and bend slightly in the same direction. There are 2-5 stigmata present in the central valve area - proximal raphe ends bend towards the stigmata.

Found in still water in slimy brown/green algae. Multiple specimens present in sample. No observable movement. Photos 3-7, specimen appears to have recently eaten.
Photo 1: 400X magnification
Photos 2-7: 1000x magnification
(ZR18)

Scale bar -10 µm
This diatom is a symmetrical biraphid. The ends of the diatom are sub-capitate. The morphology is rhombic lanceolate. The striae are curved radiate toward the center of the diatom. Within the sample the width has a wide range but the length and the number of striae per 10 µm is consistent. The sample was taken with a plankton tow at Millers Bay at West Lake Okoboji.

scale bar in image is 10 μm

macroscopic: part of the muddy stuff growing on the moss near a flark

Microscopic. Long penate diatom that looks very striped due to large striae as well as costae. The costae originates at the dorsal side sometimes ends at a point before reaching the ventral side. Both the dorsal and ventral side are curved, and the apical ends are turned up slightly. The raphe’s peak is near, but not touching the dorsal side.

in samples observed,
length range: 59-68 μm
width range: 10.5 - 13 μm
striae density range: 10-1 per 10 µm
costae density range: 2-3 per 10 µm
raphe distance in 10 µm from dorsal side: 3-4 μm
raphe distance from ventral side: 6-7 μm

Scale bar = 10 µm
First two panels in valve view, third panel is in girdle view.

Valves are linear-lanceolate and are constricted at mid-valve. The valve shape differentiates F. mesolepta from F. subconstricta, F. tenuistriata, and F. capucina.