About the Data
Species records include data on invasions history, distribution, ecology, impact, and more. These data were gathered from published literature and targeted surveys. All records have undergone expert review, unless otherwise noted.
Species Profiles
NEMESIS includes detailed information on about 500 species of marine and estuarine of invertebrates and algae introduced to the United States. Each record contains information on taxonomy, distribution, ecology, and impacts, as well as references.
Daily Invader

Palaemon elegans
Rockpool Shrimp
Rockpool Shrimp inhabits coastal rock pools, shallow rocky areas and man-made structures. It has a wide native range in the Northeast Atlantic, from the west coast of Norway to Namibia, and offshore islands, including the Azores, Cape Verde and Canary Islands. It has been introduced to the Baltic, Caspian, and Aral Seas, the Persian Gulf and Massachusetts. In parts of its introduced range, it has positive economic impacts through its use as food for commercial fish. It can also have negative ecological impacts by displacing native shrimp species.
Daily Invader for 2022-05-17