Hygrobates (Hygrobates) fluviatilis ( Ström, 1768 )

Cantallo, Harold, Gomes, Nuno, Antunes, Carlos, Martins, Duarte & Costa, Dimítri De Araújo, 2022, Checklist of water mites from mainland Portugal and its archipelagos, Zootaxa 5213 (4), pp. 336-370 : 357-358

Hygrobates (Hygrobates) fluviatilis ( Ström, 1768)

Synonym: Acarus fluviatilis Ström, 1768 (original designation)

Type material: One adult male deposited in NTNU-VM, catalogue number VP-Hyd712 ( Pešić et al. 2017)

Type locality: Norway: Heltneelva ( GBIF 2022; Ström 1768)

Geographical distribution: Palaearctic ( GBIF 2022; Ström 1768)

Distribution in Portugal: Centre: Beira Alta, in Santa Comba Dão ( Lundblad 1956).

Ecological notes: Freshwater rhithrobiont-like (on river and tributaries habitats); Organic pollution tolerant-species with preferences for streams and rheocrenes in lowland and low mountain ranges; Larval insect hosts: Chironomidae dipterans ( Gerecke et al. 2016). Found also on a sandy substrate; present in Carex spp. plants ( Lundblad 1956)

Hygrobates (Hygrobates) longipalpis ( Hermann, 1804)

Synonym: Hydrarachna longipalpis Hermann, 1804 (original designation)

Type material: Neotype designated by Pešić et al. 2019 RMNH ( Pešić et al. 2019).

Type locality: Netherlands: Gelderland ( GBIF 2022) .

Geographical distribution: Holarctic ( Gerecke et al. 2016).

Distribution in Portugal: Centre: Beira Litoral ( Valdecasas 1988), in Fonte Fria, Mealhada, Buçaco mountain ( Lundblad 1956).

Ecological notes: In standing or slow-flowing waters ( Gerecke et al. 2016; Lundblad 1956); Larval insect hosts: Chaoboridae and Chironomidae dipterans ( Gerecke et al. 2016).

Remarks: Given the recent re-establishment of the species Hygrobates prosiliens Koenike, 1915 this observation requires further analysis, as the first inhabits in standing water while H. longipalpis has a preference for slowflowing water ( Pešić et al. 2019).

Hygrobates (Hygrobates) longiporus Thor, 1898

Synonym: Hygrobates falcilaminatus Walter, 1926

Type material: Possibly not deposited in any scientific collection.

Type locality: Norway ( Thor 1898b) .

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

Distribution in Portugal: Centre: Beira Litoral, in Alcabaça municipality; and Beira Alta, in Santa Comba Dão; and Côa River, near 10 km to Vilar Formoso ( Lundblad 1956; Valdecasas 1988).

Ecological notes: In standing freshwaters, such as lakes ( Gerecke et al. 2016), clear water, on sandy and muddy bottoms, with scattered leaves, dead twigs, plants, e.g. grasses, Carex spp. and Alisma spp. ( Lundblad 1956) .

Hygrobates (Hygrobates) setosus Besseling, 1942

Synonym: Hygrobates nigromaculatus setosus Besseling, 1942 (original designation)

Type material: Female specimens in the “Collectie-Romijn” ( Besseling 1942), nowadays deposited in RMNH registration number ZMA.ACA.P.35358 and ZMA.ACA.P.35360 ( GBIF 2022).

Type locality: Netherlands: Dorpsbeekte Epe ( Besseling 1942; GBIF 2022).

Geographical distribution: Palaearctic ( Gerecke et al. 2016; Smit & van der Hammen 2000).

Distribution in Portugal: North: International Minho River Basin: Monção (tributaries, “Rios Gadanha e Mouro”) and Valença (main river stretch) municipalities ( Cantallo et al. 2021).

Material examined:

2/0/0; Pinheiros , Portugal; 42º2′14.7″N, 8º30′6,9″W; 25 September 2020; coll. by Aquamuseu Team; catalogue number NatMIP-CATr-0013 .

0/1/0; Valença , Portugal; 42º2′57.01″N, 8º37′54.74″W; 24 September 2020; coll. By Aquamuseu Team; catalogue number NatMIP-CATr-0015 .

0/1/0; Ponte de Mouro; 42°04′30.0″N, 8°23′38.5″W; 24 September 2020; coll. by Aquamuseu Team; catalogue number NatMIP-CATr-0016.

Ecological notes: In freshwater tributaries pools; with parasitic larvae of insect-dipterans ( Gerecke et al. 2016). In the present study, this species was found in association with macrophytes (“Rio Gadanha”). One specimen was found in a rock environment close to the spring (“Rio Mouro”). One individual was collected in the main sector from the Minho River, on sediment type ‘moderately sorted coarse sand’, in which the logarithmic main grain size value was 0.345 ( Cantallo et al. 2021).

Remarks: This species was reported for Portugal by Cantallo et al. (2021), which also represents the first occurrence for Southern Europe.

Hygrobates (Hygrobates) trigonicus Koenike, 1895

Synonym: Hygrobates properus Láska, 1954

Type material: Holotype ( Koenike 1895a), possibly not deposited in any scientific collection.

Type locality: Poland: Słupice ( Koenike 1895a) .

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

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

Ecological notes: Freshwater, rhithrobiont-like species, found in river and tributary environments ( Gerecke et al. 2016), in clear water, on a sandy substrate; present in plants, such as Carex spp. , Juncus spp. , Myriophyllum spp. ( Lundblad 1956) ; Larval insect hosts: Chironomidae dipterans ( Gerecke et al. 2016).