Measurements of Hydrobius male genitalia. a Paramere in lateral view. A: width of paramere (character 1.5). Curvature of paramere tip (character 1.6) = A+B b Genitalia in dorsal view. 1: Length of sclerotized part of penis. 2: Width of narrowest part of paramere (character 1.2). 3: Length of paramere (character 1.1). Robustness of paramere (character 1.3) = 3 / 2. Paramere length relative penis length (character 1.4) = 3/1. Images of Hydrobius fuscipes rottenbergii.

 
 
  Part of: Fossen EI, Ekrem T, Nilsson AN, Bergsten J (2016) Species delimitation in northern European water scavenger beetles of the genus Hydrobius (Coleoptera, Hydrophilidae). ZooKeys 564: 71-120. https://doi.org/10.3897/zookeys.564.6558