Unionicola crassipes (Müller, 1776)
Synonym: Hydrachna crassipes Müller, 1776 (original designation)
Type material: Unknown, possibly lost.
Type locality: Denmark (probably surroundings of Copenhagen) or Norway (Müller 1776).
Geographical distribution: Palaearctic (Gerecke et al. 2016).
Distribution in Portugal: Centre: Beira Alta, in Santa Comba Dão, and Côa River, near 10 km to Vilar Formoso; South: Estremadura, in Colares-Sintra municipality; Alentejo, in Ribeira de Odivelas; Guadiana River-between Serpa and Beja municipalities (Lundblad 1956; Valdecasas 1988).
Ecological notes: In standing and slow-moving freshwater ecosystems, with ectoparasitic larvae of insectchironomids and on larval Trichoptera (Gerecke et al. 2016), in clear water, on a sandy substrate; present in plants, such as Azolla spp. Batrachium spp., Carex spp., Juncus spp., Myriophyllum spp., Nymphea spp., and Scirpus spp. (Lundblad 1956).
Unionicola parvula Lundblad, 1954
Synonym: Unionicola (Pentatax) parvula Lundblad, 1954 (original designation)
Type material: Deposited in NRM: Holotype one female (Lundblad 1954), Lundblad No. Präp. 4120; Paratype: One male Lundblad No. Präp. 4381 (Lundblad 1956).
Type locality: France: Béziers (Lundblad 1954, 1956).
Geographical distribution: France and Iberian Peninsula (Gerecke et al. 2016; Lundblad 1956).
Distribution in Portugal: Centre: Beira Alta, in Santa Comba Dão (Lundblad 1956).
Ecological notes: Freshwater, at slow-moderate flowing streams(Gerecke et al. 2016), on sandy substrate; present in Carex spp. plants (Lundblad 1956).
Unionicola hankoi Szalay, 1927
Type material: Paratype: One male deposited in NRM, Lundblad No. Präp. 4501 (Lundblad 1956).
Type locality: Hungary: Balatonsee (Lundblad 1956; Szalay 1927).
Geographical distribution: Eastern and Southern Europe (Gerecke et al. 2016; Tuzovskij & Semenchenko 2015).
Distribution in Portugal: Centre: Beira Alta (Valdecasas 1988), in Côa River, near 10 km to Vilar Formoso (Lundblad 1956).
Ecological notes: In lentic and lotic freshwater ecosystems (Erman et al. 2010); Found in the mantle cavity (females) or the branchiae (deutonymph forms) of mollusc-unionids (Gerecke et al. 2016); present in Myriophyllum spp. and Juncus spp. (Lundblad 1956).