Shells of Theodoxus danubialis can reach a diameter of 9–13 millimetres (0.35–0.51 in). These shells are quite flattened, with 3-3.5 whorls. The surface has a characteristic dark brown zigzag drawing on a light background. The width of the zigzag lines is variable. The mouth is round to slightly elliptical. The operculum is pale yellow. The edge is brown and slightly thickened. The body of the snail is bright with a wide base. The antennae are long and pointed.
This species needs clean, oxygen-rich rivers. These snails live on hard benthic substrates,[3] typically rocks or stony ground and feed mainly on diatoms.
Bibliography
Peter Glöer: Die Tierwelt Deutschlands. Mollusca I Süßwassergastropoden Nord- und Mitteleuropas Bestimmungsschlüssel, Lebensweise, Verbreitung. 2. neubearb. Aufl., 327 S., ConchBooks, Hackenheim 2002 ISBN3-925919-60-0
Rosina Fechter und Gerhard Falkner: Weichtiere. 287 S., Mosaik-Verlag, München 1990 (Steinbachs Naturführer 10) ISBN3-570-03414-3
Jürgen H. Jungbluth und Dietrich von Knore: Trivialnamen der Land- und Süßwassermollusken Deutschlands (Gastropoda et Bivalvia). Mollusca, 26(1): 105-156, Dresden 2008 ISSN1864-5127
References
^Pfeiffer, 1828. Naturgeschichte deutscher Land- und Süsswasser-Mollusken. Vol. 3 (1828): 84 pp. + 8 tables. Weimar. (Landes-Industrie-Comptoir).
^ ab(in Czech) Horsák M., Juřičková L., Beran L., Čejka T. & Dvořák L. (2010). "Komentovaný seznam měkkýšů zjištěných ve volné přírodě České a Slovenské republiky. [Annotated list of mollusc species recorded outdoors in the Czech and Slovak Republics]". Malacologica Bohemoslovaca, Suppl. 1: 1-37. PDF.
^Glöer P. & Meier-Brook C. (2003) Süsswassermollusken. DJN, pp. 134, page 108, ISBN3-923376-02-2