Pachychilus, common name the jute snails,[2] is a genus of freshwater snails with an operculum, aquatic gastropod mollusk in the family Pachychilidae.

[3] The distribution of species in the genus Pachychilus includes: Species within the genus Pachychilus include: subgenus Pachychiloides Wenz, 1939[5] One of the Maya peoples, the Lacandon people, now Mexico's native peoples from state Chiapas, use Pachychilus indiorum, known locally as "t’unu", as a type of protein supplement to their diet when animal protein is unavailable.

[7] In addition, the shells from this "chuti" snail have great nutritional value, as they provide calcium and slaked lime when burnt.

They are often preferred as a lime source over local limestone or other freshwater snail species for their purity as an alkali.

Slaked lime allows the release of amino acids such as tryptophan and lysine and the vitamin niacin, which would otherwise be unavailable from the maize (unable to be metabolized) if the lime were not added.