Striatura - Striate Snails (Family Gastrodontidae)

Striate Snails are tiny snails in the 1.5-2 mm diameter range with distinctive spiral striae and radial ridges. The spiral striae are very noticeable (if not worn down) on the embryonic whorls. More recent whorls add distinct and regularly spaced axial ridges to those spiral striae cutting forming a coarse-looking surface.

Two species were in the databases for Indiana - the Median Striate, Striatura meridionalis (Pilsbry and Ferriss, 1906) and the Fine-ribbed Striate, Striatura milium (E. S. Morse, 1859) plus a third, the Black Striate, Striatura ferrea E.S. Morse, 1864,  in only one county (Perry) from a 2006 observation.

Comparison: Striatura meriodionalis is 1.7-1.8 mm in diameter, with spiral striae prominent and extending to apex. Striatura milium is about ~ 1.5 mm in diameter, with spiral striae less prominent. Striatura ferrea is larger, 2.5-3 mm in diameter; the umbilicus is more narrow than others; and it has low radial ridges and "delicate" spiral striae (Hotopp et al. 2013). 

Habitat: All may be found in woodlands, among leaf litter and small woody debris; easy to miss; similar to Punctum minutissimum and Hawaiia minuscula on first look.

Striatura meridionalis (Pilsbry and Ferriss, 1906)

Striatura meridionalis (Pilsbry and Ferriss, 1906)

Median Striate
Striatura meridionalis (Pilsbry and Ferriss, 1906)


Striatura milium (E. S. Morse, 1859)

Striatura milium (E. S. Morse, 1859)

Fine-ribbed Striate
Striatura milium (E. S. Morse, 1859)

See image here

Black Striate

Striatura ferrea E.S. Morse, 1864