Armiger crista ( Linnaeus, 1758 )

Marković, Vanja, Gojšina, Vukašin, Novaković, Boris, Božanić, Milenka, Stojanović, Katarina, Karan-Žnidaršič, Tamara & Živić, Ivana, 2021, The freshwater molluscs of Serbia: Annotated checklist with remarks on distribution and protection status, Zootaxa 5003 (1), pp. 1-64 : 30

58. Armiger crista ( Linnaeus, 1758)

Findings in Serbia.

Gyraulus (Armiger) crista: Novaković (2015 pers. comm.); Gojšina (2021 pers. comm.).

Common name. Nautilus ramshorn.

Morphology. Minute snail (up to 3 mm diameter). Shell is thin and translucent, finely striated and sometimes ribbed. Aperture is nearly circular, while the shell is convex at the upper side and flat, or convex, on the lower side. For more details see Welter-Schultes (2012: 62, figure at the bottom of the page).

Distribution and ecology. Holarctic species up to 1400 m.a.s.l. (a few lowland findings in Serbia, up to 100 m. a.s.l.) Inhabits permanent smaller water bodies, lakes and ponds rich in vegetation. Can tolerate soft waters ( Welter-Schultes 2012). In Serbia, it has been found in the Danube (Kovin Municipality) and Plazović Rivers.

Other remarks. Shell morphology can be variable, hence three morphotypes: Armiger c. f. nautileus (smooth form), A. c. f. cristatus (ribbed form) and A. c. f. spinulosus (jagged form) ( Glöer 2019). On the IUCN Red List of threatened species, it has been assessed as LC ( Seddon & Killeen 2011b).

Genus Gyraulus Charpentier, 1837