Arrenurus (Arrenurus) albator (Müller, 1776)

Synonym: Hydrachna albator Müller, 1776 (original designation)

Type material: Unknown, possibly lost.

Type locality: Denmark (probably surroundings of Copenhagen) or Norway (Müller 1776) .

Geographical distribution: Western Palaearctic (Gerecke et al. 2016).

Distribution in Portugal: Centre: Beira Alta (Valdecasas 1988), in Côa River, near 10 km to Vilar Formoso (Lundblad 1956).

Ecological notes: In fresh-oligohaline and eutrophic slow-flowing waters, but with a preference for large water bodies; Larval insects hosts: Chaoboridae (Diptera), Chironomidae (Diptera) and Hydrophilus spp. larvae ( Coleoptera) (Gerecke et al. 2016); present in Juncus spp., Myriophyllum spp. (Lundblad 1956) .