Most commonly observed introduced mollusk documented using iNaturalist by US state
20 states reported Leopard Slug, Limax maximus, as the most commonly observed introduced mollusk
9 states reported Asian Clam, Corbicula fluminea, as the most commonly observed introduced mollusk
6 states reported Garden Snail, Cornu aspersum, as the most commonly observed introduced mollusk
4 states reported Common Periwinkle, Littorina littorea, as the most commonly observed introduced mollusk
3 states reported Chinese Mystery Snail, Cipangopaludina chinensis, as the most commonly observed introduced mollusk
2 states reported Milky Slug, Deroceras reticulatum, as the most commonly observed introduced mollusk
1 state reported African Giant Snail, Lissachatina fulica, as the most commonly observed introduced mollusk
1 state reported Black-velvet Leatherleaf, Belocaulus angustipes, as the most commonly observed introduced mollusk
1 state reported Decollate Snail, Rumina decollata, as the most commonly observed introduced mollusk
1 state reported Brown-lipped Snail, Cepaea nemoralis, as the most commonly observed introduced mollusk
1 state reported Cuban Brown Snail, Zachrysia provisoria, as the most commonly observed introduced mollusk
1 state reported Island Apple Snail, Pomacea maculata, as the most commonly observed introduced mollusk
1 state reported Red-rimmed Melania, Melanoides tuberculata, as the most commonly observed introduced mollusk
1 state reported Zebra Mussel, Dreissena polymorpha, as the most commonly observed introduced mollusk
Top 10 most commonly observed mollusks in the US (reported on iNaturalist)
Garden Snail, Cornu aspersum - Introduced to the US
Leopard Slug, Limax maximus - Introduced to the US
Pacific Banana Slug, Ariolimax columbianus - Native to the US (but may be considered introduced in some states)
Asian Clam, Corbicula fluminea - Introduced to the US
California Mussel, Mytilus californianus - Native to the US (but may be considered introduced in some states)
Milk Snail, Otala lactea - Introduced to the US
Opalescent Nudibranch, Hermissenda opalescens - Native to the US (but may be considered introduced in some states)
Brown-lipped Snail, Cepaea nemoralis - Introduced to the US
Decollate Snail, Rumina decollata - Introduced to the US
Black Tegula, Tegula funebralis - Native to the US (but may be considered introduced in some states)
(last updated November 2023