First record of oriental shrimp, Palaemon macrodactylus Rathbun, 1902 in Varna Lake, Bulgaria

In September 2009 a non-native shrimp species was found at two sampling sites in Varna Lake, a brackish coastal water body connected to the Bulgarian Black Sea. Diagnosis based on morphological features confirmed that the examined individuals belonged to the species Palaemon macrodactylus Rathbun, 1902. All specimens found were ovigerous, 2+ year females suggesting the presence of a viable population in the system. Possible ways of introduction and community effects for Varna Lake are discussed.