<i>Acilius sulcatus</i> (Linnæus, 1758). Body length 17.1 mm without antennae. Determined by kerbtier.de. Germany: Niedersachsen, Göttingen, small pond in Bramwald forst near Ellershausen.
<a href="//commons.wikimedia.org/wiki/User:Kryp" title="User:Kryp">Francisco Welter-Schultes</a>
<span class="int-own-work" lang="en">Own work</span>