Occurrence of Eurycercus (Teretifrons) glacialis Lilljeborg, 1887 (Cladocera, Chydoridae) on Sakhalin Island

Here we report the first observation of Eurycercus glacialis on Sakhalin Island. The abundance of this species in a lake was positively associated with aquatic vegetation. The morphological characteristics of the specimens collected on Sakhalin are described.