Hippodonta

Hippodonta are small diatoms with thick glass cell walls. Their shapes range from elongated ovals to double-headed bowling pins. Often, their striae start off radiate at the valve center but reverse and become convergent at the tips. Hippodonta live in bottom sediments, and tend to live in waters with higher salt concentrations.

H. capitata

Cells are 12-28 µm in length, 5-8.5 µm in width.
Rows of striae are 8-11 per 10 µm.
Ends are narrow, then bulged. They have an unornamented region.
Striae are thick and radiate at the center, becoming parallel to convergent at the ends.

For more information, visit diatoms.org here.

A5m1 Hippodonta capitata (_)_edited

A5m1 Hippodonta capitata (_)2_edited

H. coxiae

Cells are 16-21 µm in length, 4.2-5.2 µm in width.
Rows of striae are 11-13 per 10 µm.
Tips are blunted, and do not bulge at the end unlike C. capitata.
Striae are slightly radiate at the valve center and slightly convergent at the ends.

For more information, visit diatoms.org here.

A3m1 Hippodonta cf. coxiae (_)_edited

Hippodonta sp. girdle view

Like most elongate diatoms, Hippodonta cannot be identified by species in its girdle fiew; there are not enough defining characteristics, including striae, to tell. However, it is important to understand what the girdle view looks like so that one can know what they are looking at on a genus level.

A8m1 Hippodonta sp1_edited

A3m1 Hippodonta_edited

A3m1 Hippodonta (girdle view, dividing)_edited

Mendota Diatoms

A local field guide to Wisconsin algae

Hippodonta

H. capitata

Cells are 12-28 µm in length, 5-8.5 µm in width.

Rows of striae are 8-11 per 10 µm.

Ends are narrow, then bulged. They have an unornamented region.

Striae are thick and radiate at the center, becoming parallel to convergent at the ends.

For more information, visit diatoms.org here.

H. coxiae

Cells are 16-21 µm in length, 4.2-5.2 µm in width.

Rows of striae are 11-13 per 10 µm.

Tips are blunted, and do not bulge at the end unlike C. capitata.

Striae are slightly radiate at the valve center and slightly convergent at the ends.

For more information, visit diatoms.org here.

Hippodonta sp. girdle view

Like most elongate diatoms, Hippodonta cannot be identified by species in its girdle fiew; there are not enough defining characteristics, including striae, to tell. However, it is important to understand what the girdle view looks like so that one can know what they are looking at on a genus level.