The species is a small damselfly, about 29 millimetres (1.1 in) long, predominantly black with iridescent blue markings.

Viewed from the side, the second and eighth segment of the abdomen of the male are mostly blue, which distinguishes it from the red-eyed damselfly where these are mostly black.

This damselfly breeds in ponds, lakes and ditches and, in continental Europe, sluggish rivers.

Eggs are laid while in tandem, into the stems and leaves of floating plants.

The first British record was in Essex on 17 July 1999 and is documented in Dewick and Gerussi (2000).