Kaliwatan sa bakukangon ang Hydraena imperatrix.^[1] Una ning gihulagway ni Knisch [as Kniž ni adtong 1919.^[2] Ang Hydraena imperatrix sakop sa kahenera nga Hydraena, ug kabanay nga Hydraenidae.^[1][3]

Kini nga matang hayop na sabwag sa:

• Italya

Walay nalista nga matang nga sama niini.^[1]

1. ↑ ^{1.0 1.1 1.2} Roskov Y., Kunze T., Orrell T., Abucay L., Paglinawan L., Culham A., Bailly N., Kirk P., Bourgoin T., Baillargeon G., Decock W., De Wever A., Didžiulis V. (ed) (2019). "Species 2000 & ITIS Catalogue of Life: 2019 Annual Checklist". Species 2000: Naturalis, Leiden, the Netherlands. ISSN 2405-884X. TaxonID: 53252417. Retrieved 2019-11-11. {{cite web}}: |author= has generic name (help)CS1 maint: multiple names: authors list (link)
2. ↑ Knisch, A. [as Kniž]. (1919) Zur Kenntnis der palaearktischen Hydrophiliden (I. Beitrag). , Entomologische Blätter, 15 (1-3): 11-16.
3. ↑ Newton A.F. (2019). StaphBase: Staphyliniformia world catalog database (version Nov 2018). In: Species 2000 & ITIS Catalogue of Life, 2019 Annual Checklist (Roskov Y., Ower G., Orrell T., Nicolson D., Bailly N., Kirk P.M., Bourgoin T., DeWalt R.E., Decock W., Nieukerken E. van, Zarucchi J., Penev L., eds.). Digital resource at www.catalogueoflife.org/annual-checklist/2019. Species 2000: Naturalis, Leiden, the Netherlands. ISSN 2405-884X.