Palaemon elegans

Palaemon elegans sometimes known by the common name rockpool shrimp, is a species of shrimp of the family Palaemonidae. It is found in the Atlantic, the Baltic, the Mediterranean, the Black Sea, the Caspian Sea and the Azores. It is similar to three other members of the genus Palaemon: Palaemon serratus, Palaemon longirostris and Palaemon adspersus, and has displaced or replaced populations of Palaemon adspersus in some locations. It is considered an invasive species in parts of the United States.