The freshwater molluscs of Serbia: Annotated checklist with remarks on distribution and protection status Author Marković, Vanja Author Gojšina, Vukašin Author Novaković, Boris Author Božanić, Milenka Author Stojanović, Katarina Author Karan-Žnidaršič, Tamara Author Živić, Ivana text Zootaxa 2021 2021-07-16 5003 1 1 64 journal article 218052 10.11646/zootaxa.5003.1.1 aceedc3f-3f24-490c-8046-7528c30aac10 1175-5326 5120059 8C98CC0B-18AF-418A-A794-AA3CA9CB7409 76. Sphaerium rivicola ( Lamarck, 1818 ) Findings in Serbia . Sphaerium rivicola : Arambašić (1994) ; Tomović et al. (2010 b , 2014); Paunović et al. (2005 , 2007 b , 2008); Martinović-Vitanović et al . (2007 , 2013); Lucić et al . (2015) . Common name . River orb mussel, nut orb mussel. Morphology . Small bivalve. Shell is rounded oval in outline shape and typically reaches 18–22 mm in length, 15–17 mm in height, and 10–13 mm in depth (more details in Welter-Schultes, 2012 , page 25, figure in the middle of the page). Distribution and ecology . Palearctic species common in the lowland regions of Central and Eastern Europe ( Zhadin 1965 ). It prefers fine substrate (silt, mud, sand) in larger slow–flowing rivers and canals, rarely it could be found in standing waters. In Serbia , it mostly inhabits large Pannonian/lowlands rivers (the Danube, Tisza and Sava Rivers). Other remarks . One of the largest species of Sphaerium occurring in Serbia . There are 10 nominal species known as synonyms ( Graf & Cummings 2021 ). On the IUCN Red List of threatened species it has been assessed as LC, yet with decreasing population trend, for Europe ( von Proschwitz & Killeen 2011 ), and as VU on the global scale ( Van Damme 2011 d ).