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.
Peregrine Crab (Varuna litterata) is a euryhaline grapsid crab that inhabits rivers, brackish waters and seas throughout the Indo-Pacific region. This species is important commercially throughout its native range for human consumption, however no substantial trade information was found. There are records of natural range expansion for Varuna litterata within the native range with some information on potential impacts in those areas. However no actual nonnative introductions have been reported, therefore there is no information on the impacts of introduction. The history of invasiveness is No Known Nonnative Population. The overall climate match for the contiguous United States was Medium. A high match was found along the Atlantic Coast from southern coastal Virginia to Florida, as well as in South Texas, and parts of Oklahoma, and Missouri. This species migrates between marine and non-marine environments. Because not all locations in the United States are conducive to such migration, inland establishment of this species may be limited according to the existing connectivity between marine and non-marine environments. The certainty of assessment is Low due to limited information on the impacts of introduction. The overall risk assessment category for Varuna litterata is Uncertain.