Ecological Risk Screening Summary - Crested Ramshorn (Drepanotrema kermatoides) - Uncertain Risk

Drepanotrema kermatoides, the Crested Ramshorn, is a snail that is native to South America, Central America, and the Caribbean, although its native status outside of South America has been questioned. This is a small aquatic snail species that lives in association with aquatic macrophytes in lentic environments. This species is not available in trade, and no regulations on its trade could be found. There are two records of D. kermatoides in Texas from 1949 and 1968, but the status of its population in the United States is unknown, and more recent records of its presence could not be found. The History of Invasiveness for D. kermatoides is classified as No Known Nonnative Population due to the lack of confirmed introductions, information on impacts of introduction, and trade history. The climate matching analysis for the contiguous United States indicates establishment concern for this species, with high matching being located in Southern and Eastern States. The Certainty of Assessment for this ERSS is classified as Low due to a lack of information on introductions, impacts, and trade, and uncertainty around the source points for the climate matching analysis. The Overall Risk Assessment Category for D. kermatoides in the contiguous United States is Uncertain.

Species that are considered uncertain risk need a more in-depth assessment beyond the Risk Summary to better define the species’ risk to U.S. environments.