on the bottom with rubber mats. In August 2020 routine inspections in Wyoming found several watercraft to be heavily infested including one with C. fluminea. On October 16, 2020 the Montana Department of Fish, Wildlife and Parks recommended that Lake Elmo - in Billings - be drained to dry out and freeze to death the C. fluminea infestation there. Taxonomy Corbicula fluminea is a species of freshwater clam, an aquatic bivalve mollusk in the family Cyrenidae. C. fluminea is often confused with Corbicula fluminalis due to the two species' similar color and texture. Two species may be present in some introduced populations: C. fluminea and C. fluminalis. The names themselves are similar in the literature (e.g. by being called "Corbicula fluminata"). The ratio of width and height in C. fluminea is on average 1.1. In C. fluminalis it is smaller (0.97); still, there is much variation and considerable overlap in shape. Most easily, they can be distinguished by the number of ribs on the shell; C. fluminea has 7 to 14 ribs per cm, C. fluminalis 13 to 28. This character is already clearly recognizable (albeit only by direct comparison) in very small (5 mm diameter) specimens. In addition, when viewed from the ventral side (looking at the opening between the shells), C. fluminalis is rounder, almost heart-shaped, while C. fluminea has a slightly flatter shape like a teardrop with a notched broad end. Small specimens of C. fluminalis are almost spherical, while those of C. fluminea are decidedly flattened. All these differences except the rib number are a consequence of C. fluminalis having a markedly more swollen, pointed and protruding umbo. See also List of introduced molluscs species of Venezuela References Weitere, M. et al. (2009) Linking environmental warming to the fitness of the invasive clam Corbicula fluminea, Global Change Biology, Volume 15 Issue 12, Pages 2838 - 2851 Further reading External links USGS (NAS)- Nonindigenous Aquatic Species "Aquatic Immigrants of the Northeast, No. 4: Asian Clam, Corbicula fluminea" Anatomy of Corbicula fluminea, Invertebrate Anatomy OnLine GLANSIS Species Fact Sheet, United States Geological Survey Species Profile - Asian Clam (Corbicula fluminea), National Invasive Species Information Center, United States National Agricultural Library. Lists general information and resources for Asian Clam. Cyrenidae Molluscs described in 1774 Taxa named by Otto Friedrich Müller