The valve of this taxon is lanceolate to elliptical-lanceolate and the ends are obtuse and slightly protracted. The axial area is narrow and slightly widens toward the center area. The central area is transverse and irregular in shape. The striae are radiate and irregular in length (Patrick and Reimer 1966).
Synonyms
Pinnularia gastrum Ehr., Phys. Abh. Akad. Wiss. Berlin, for 1841:421, pl. 3(7), fig. 23. 1843 (Patrick and Reimer 1966).
Navicula gastrum (Ehr.) Kutz., Bacill., p.94, pl.28, fig. 56. 1844 (Patrick and Reimer 1966).
Navicula varians Greg., Trans. Micr. Soc. London, New ser., 3:11, pl. 2, figs. 27-28(in part). 1855 (Patrick and Reimer 1966).
Navicula gastrum f. maxima Temp. & Perag., Diat. Monde Entier, 2nd ed., p. 194. 1910 (Patrick and Reimer 1966).
Ecology
This taxon prefers fresh to slightly brackish water (Patrick and Reimer 1966).
Length is 25 to 60 micrometers (Patrick and Reimer 1966).
Width is 12 to 20 micrometers (Patrick and Reimer 1966).
Striae at the center of the valve are 8 to 10 in 10 micrometers (Patrick and Reimer 1966).
Striae at the ends of the valve are 12 in 10 micrometers (Patrick and Reimer 1966).
This image was taken using DIC.