Ecological Risk Screening Summary - Ghost Ramshorn (Biomphalaria havanensis) - Uncertain Risk

Biomphalaria havanensis, Ghost Ramshorn, is a snail native to the southern United States, Mexico, Central America, and the Caribbean. This freshwater snail can tolerate a broad range of habitats from lakes and rivers to catfish ponds. Biomphalaria havanensis is thought to be transported unintentionally via hitchhiking on aquatic plants or stocked fish. It can serve as a host of the trematode parasite Bolbophorus damnificus, which is known to contribute to mortality in channel catfish aquaculture, and it may also be capable of harboring a parasite responsible for human schistosomiasis. However, the impacts of introduction of B. havanensis outside the native range remain unknown. Arkansas is the only State the regulates this species, prohibiting importation for aquaculture and private pond stocking. The History of Invasiveness for Biomphalaria havanensis is classified as Data Deficient due to the lack of information regarding actual impacts of introductions. The climate matching analysis for the contiguous United States indicates establishment concern for this species outside its native range. The highest climate matches were found along the southern boundary of the contiguous United States, including areas both within and outside the native range. The Certainty of Assessment for this species is classified as Low due to lack of information on impacts of introductions. The Overall Risk Assessment Category for Biomphalaria havanensis in the contiguous United States is Uncertain.