New records of water mites from New Zealand, with the description of three new genera and ten new species (Acari: Hydrachnidia)

Many new records are presented of rare water mites from New Zealand. Three new genera are described, i.e. Moanabates n. gen. (Hygrobatidae), Asperaturus n. gen. and Minyaturus n. gen. (Aturidae: Notoaturinae), and ten new species, i.e. Limnesia moanaensis n. sp., L. pseudozelandica n. sp., L. quinqueglandulosa n. sp., Zelandobates tongariro n. sp., Z. occidentalis n. sp., Moanabates moanaensis n. sp., Asperaturus petiolatus n. sp., Minyaturus minutulus n. sp., Paratryssaturus montanus n. sp. and Penemideopsis novaezelandica n. sp. Australiobates lacustris Smit, 1996 is synonymized with Australiobates setipalpis Cook, 1983. The male is for the first time described for Limnesia auspexa Cook, 1983, Apeltosperchon zelandicus Cook, 1983, Australiobates solomis Cook, 1983, Kritaturus vinnulus Cook, 1983 and Taintaturus longipileatus Smit, 2017, the female is for the first time described for Schwoerbelaturus aturoides (Schwoerbel, 1984).

In this paper three new genera and 10 new species are described. Moreover, new records are given of species with few records (less than five) known thus far. These data are based on collection trips of the first author in 1992 (South Island); 2000 (North and South Island), 2014 (North and South Island), 2019 (North and South Island) and 2020 (South Island). The Notoaturinae of the 2014 and 2019 collection trips were published by Smit (2017Smit ( , 2019).
This study reveals that the water mite fauna of New Zealand is still insufficiently known. This applies especially to the hyporheic fauna.

Materials and methods
Unless stated otherwise, all material was collected by the first author. Holotypes and paratypes will be lodged in the Museum of New Zealand, Wellington (NMNZ), paratypes and all nontype material in Naturalis Biodiversity Center, Leiden (RMNH). The interstitial sampling was done by the KaramanChappuis method. Preferably the locations were situated in streams draining natural habitats. In streams draining pastures and exotic pine forest the diversity of water mites is low or water mites are even absent (Boulton et al. 1997). The following abbreviations are used: asl = above sea level; CxIV -fourth coxae; Cxgl4 -coxoglandularia 4; P15palp segments 15; IVleg2 -second segment of fourth leg. All measurements are in µm, measurements of palp and leg segments are of the dorsal margins. Ventral length is measured from the tip of CxI till posterior idiosoma margin. For the glandularia notations Wiles (1997) is followed. The coordinates are taken with a GPS, but those given as degrees, minutes and seconds are taken from Google Earth and are by approximation. Numbers are given as male/female/deutonymph or adult/deutonymph. The distribution data are from the papers of Stout and Cook (see above), unless stated otherwise.

Taxonomy Family Hydrachnidae Leach Genus Hydrachna Müller, 1776
A genus with numerous species worldwide.
Distribution. Previously reported from three locations, all from North Island (Stout 1953b), and reported here for the first time from South Island.

Zelandothyas diamphida
Distribution. Previously known from two locations from South Island.

Family Eylaidae Leach
Genus Eylais Latreille, 1796 A genus with numerous species known worldwide.
Eylais schauinslandi Koenike, 1900 New record. North Island. Distribution. Previously reported from one locality from South Island (Koenike 1900) and from two localities from North Island (Stout 1953a).

Family Hydryphantidae Piersig
Subfamily Pseudohydryphantinae K. Viets Genus Pseudohydryphantes K. Viets, 1907 A genus with several species from the Holarctic and Australia. From New Zealand one species is known.
Distribution. Previously known from the type locality on South Island only. As the nymph has not been described, the assignment is not certain.

Anisitsiellides arraphus
Male: Idiosoma 688 long and 608 wide, ventrally 697 long. Integument lineated, brownish. Dorsal shield 620 long and 502 wide, with three pairs of glandularia and the postocularia. Dorsal furrow with five pairs of glandularia. Gnathosoma not attached to a protrusible tube. Gnathosomal bay medially with a cleft. Medial margin of CxIII straight, Cxgl4 on CxIII near suture line of CxIII/IV; posterior margin of CxIV rounded. No ridge anterior to insertions of fourth legs. Genital field with three pairs of acetabula, the anterior pair more distanced from the second pair than the second and third pair, anterior margin straight; gonopore 110 long. Length of P15: 24, 86, 60, 132, 41. P2 with a short, stout seta, P4 ventrally with a small setal tubercle. Length of Ileg46: 92, 110, 130 (till tip of segment). Length of IVleg46: 130, 156, 162; IVleg6 with a 92 long terminal seta. Fourth leg segments with numerous stout setae. Excretory pore incorporated in the ventral shield.
Distribution. Previously known from three localities from North Island. Hopkins (1967) described this species as Mamersella anomala, but according to Panesar (2004) this is a Limnesia. However, Limnesia anomala is preoccupied by L. anomala Koenike, 1895. As L. auspexa Cook is conspecific with Hopkins's species, this becomes the first available name. According to Hopkins (1967) the holotype is a male, but it is clear that this is a female Limnesia. Therefore, the male has not yet been described, and a description is given here. Remarks. The male of L. auspexa has three pairs of glandularia on the dorsal shield too (assuming that fullygrown L. moanaensis has a dorsal shield with the same number of glandularia), but the gnathosoma of L. auspexa is not attached to a protrusable tube, the acetabula are elongated and narrow and a ridge is lacking anterior to the insertions of the fourth legs.
Limnesia (Limnesia) pseudozelandica n. sp. Diagnosis. Dorsum with eight pairs of glandularia, six of these on the dorsal shield. CxIII with a relatively long, straight medial margin. Gnathosoma attached to a protrusible tube. Acetabula of separate genital plates.
Etymology. Named for its superficial resemblance to L. zelandica Cook, 1983. Remarks. With the key of Cook (1983) the new species keys out as L. testacea Hopkins, 1969. Differences with the latter species (in brackets) are the long medial margin of CxIII (short), no ridge anterior to insertion of fourth legs (with ridge) and the gonopore is shorter. A second species with the dorsal shield with six pairs of glandularia is L. zelandica Cook, 1983. This species has the gnathosoma attached to a protrusible tube too. Differences with the new species (in brackets) are the presence of three pairs of glandularia in the dorsal furrow (two pairs), the presence of a ridge anterior to the insertions of the legs (no ridge), rounded medial margins of CxIII (straight), and the integument is pigmented (not pigmented). Diagnosis. Female: Dorsal shield with five pairs of glandularia, dorsal furrow with three pairs of glandularia, gnathosoma not attached to a protrusible tube, Cxgl4 not on coxae but posterior to CxIII, its associated setae in the middle of CxIII.
Male: Unknown. Etymology. Named for the presence of five pairs of glandularia on the dorsal shield.
Remarks. The only other species with five pairs of glandularia on the dorsal shield is L. conroyi Cook, 1983, but this species has four pairs of glandularia in the dorsal furrow, the gnathosoma is attached to a protrusible tube and Cxgl4 is lying near the suture line of CxIII/IV. Limnesia (Limnesia) rotoruaensis Smit, 2002 New record. North Island. 17/18/3/, Lake Rotorua at Rotorua, 38°07.801 ′ S 176°15.920 ′ E, alt. 285 m asl, 7xii2014.
Distribution. Known from the type locality only, i.e. Lake Rotorua.
Distribution. Previously known from the type locality only, i.e. Lake Ianthe, and here reported for the first time from North Island.

Oxus (Flabellifrontipoda) mastigophorus
Distribution. Previously known from two localities from North and South Island, and here reported for the first time from Stewart Island.
Oxus (Flabellifrontipoda) zelandicus (Hopkins, 1975) New records. North Island. 0/1/0, Kakekino Stream, crossing TaihapeNapier  Distribution. Previously known from three localities from North Island, and here reported for the first time from South Island.

Family Sperchontidae Thor
Subfamily Apeltosperchontinae Besch Genus Apeltosperchon Besch, 1964 A small genus with two species known, one from Chile (Besch 1964) and one from New Zealand. Cook, 1983  Distribution. Previously know from three specimens from three locations only. From the quite large number of locations given above, it can be concluded that the species is rather common.

Aciculacarus amalis
Distribution. Previously known from the type locality from North Island only, and here reported for the first time from South Island. Hopkins, 1975 New records.

Genus Australiobates Lundblad, 1941
A genus with a Gondwanan distribution, with numerous species known.
Remarks. The illustrations of Cook (1983) show the male with an ovalshaped gonopore and the genital field anteriorly with flexible setae. However, examination of a picture of the holotype (see https://collections.tepapa.govt.nz/object/125042#open-iiifViewer) shows a gonopore which becomes narrower anteriorly, and the anterior margin has long, more or less stiff setae. The description of Australiobates lacustris was based on the latter characteristics. Recent studies on hygrobatids, based on morphological and molecular evidence, have shown that lake and stream forms might belong to different species (Martin et al. 2010, Pešić et al. 2019. However, based on the morphology, we conclude that A. lacustris is a synonym of A. setipalpis. All previous records were from streams.
Distribution. Many records from North and South Island.
Australiobates (Australiobates) solomis Cook, 1983  Distribution. The male of this species has not been described. Previously known from four localities on North and South Island.
Distribution. Previously known from two localities from North Island.
Genus Hopkinsobates Cook, 1983 A monotypic genus known from New Zealand only.
Hopkinsobates suzannae Cook, 1983 New records. North Island.   (4) Diagnosis. Dorsum with a large unpaired anterior plate, with three pairs of glandularia in male, this plate in female without glandularia.
Description. Male: Idiosoma smooth, dorsally 575 long and 425 wide, ventrally 684 long. Dorsum with a large unpaired anterior plate, 381 long, 318 wide, with three pairs of glandularia and the postocularia, covering more than half of the dorsum. Posterior to the large anterior dorsal plate a smaller unpaired platelet, 111 long, 147 wide, a pair if small platelets and three pairs of glandularia platelets. Coxae in three groups, coxal field 411 long, 500 wide, CxI+II fused medially. Cxgl4 located near suture line of CxIII/IV. Posterior to CxIV a pair of large platelets, Cxgl3 fused with these platelets. Genital field, 181 long, 150 wide, with three pairs of acetabula, gonopore 91 long. Excretory pore fused with posterior margin of genital field. Lateral to genital field a pair of platelets, each with two glandularia. Length of P15: 33, 77, 78, 98, 55. P2 and P3 with many papillae, these not extending onto medial margin; P4 stocky with a large ventral projection. Length of Ileg46: 120, 122, 133. Ileg5 anteroventrally with a pointed stout seta. Length of IVleg46: 161, 158, 125.
Female: Idiosoma dorsally 744 long and 544 wide, ventrally 788 long. Dorsum with a large unpaired anterior plate, 456 long, 286 wide, with the postocularia, and a smaller unpaired posterior plate, 141 long, 186 wide. Moreover, dorsum with five pairs of platelets, two of these pairs without glandularia. Anterolateral platelets 275 long, located lateral to large anterior platelet, each with a glandularium. Coxae in three groups, coxal field 488 long, 531 wide, CxI+II fused medially. Cxgl4 located near suture line of CxIII/IV. Posterior to CxIV a pair of large platelets. Cxgl3 on small platelets, not fused with the latter large platelets. Genital field with three pairs of acetabula, length of genital field (from anterior margin of pregenital sclerite to posterior margin of postgenital sclerite) 209, width of genital field 194, genital plate 138 long. Pregenital sclerite 150 wide, gonopore 138 in length. Lateral to genital field two pairs of small platelets. Cxgl2 and excretory pore immediately posterior to genital field. Length of P15: 34, 100, 103, 125, 59; palp as in male. Length of Ileg46: 128, 134, 131. Ileg5 anteroventrally with a blunt, stout seta. Length of IVleg46: 175, 188, 153. Etymology. Named for its western occurrence in South Island. Remarks. The new species differs from Z. crinitus in the absence of large dorsal glandularia setae. Moreover, in the male the unpaired anterodorsal plate has three pairs of glandularia (none in crinitus), in the female the unpaired anterodorsal plate has no glandularia (three pairs in crinitus). The male differs from Z. tongariro n. sp. in the presence of three pairs of glandularia on the anterodorsal unpaired plate (none in tongariro) and excretory pore fused with genital field (unfused in tongariro). Moanabates n. gen.
Zoobank: 736BA860-45B5-49DC-BA2E-5BC0CF74112F Diagnosis. Idiosoma rugose. CxII and CxIII elongated posteriorly, apodemes large exceeding Cx1+2 caudal margin especially in male; male gonopore slitlike; P2 with a large ventral projection with large papillae, P3 without papillae, P4 stocky with a long, whiplike seta (longer in female than in male), P5 with a pair of ventrally situated spatulate setae in the both sexes.  are absent in the new genus, and Corticacarus species do not have a slitlike gonopore and lack the long whiplike seta of P4.
Diagnosis. As given for the genus. Description. Male: Idiosoma rugose, dorsally 638 long and 484 wide, ventrally 677 long. Dorsum with a large unpaired, papillose anterior plate, 394 long, 363 wide, with three pairs of glandularia and a smaller posterior plate, 138 long and 175 wide. Posterior to the anterior dorsal plate four pairs of platelets, two of these with glandularia. Coxae in three groups, CxI+II fused medially. CxII and CxIII elongated, extending halfway medial margin of CxIV. Cxgl4 located near suture line of CxIII/IV. Posterior to CxIV a pair of large platelets, Cxgl3 not fused with the latter platelets. Genital field on a plate, 202 long, with three pairs of acetabula. Gonopore slitlike, 81 long. Posterolateral to genital field four pairs of platelets, three of these with glandularia. Excretory pore sclerotized posterior to genital field. Length of P15: 34, 78, 75, 70, 60. P2 with a large ventral extension with papillae, P4 stocky with a long, whiplike seta and a truncate ventral extension, P5 as in female. Length of Ileg46: 102, 105, 103. Ileg5 anteroventrally with a somewhat blunt, stout seta. Length of IVleg46: 133, 136, 134.
Female: Idiosoma dorsally 750 long and 659 wide, ventrally 822 long. Dorsum with a large unpaired plate, 444 long, 291 wide with a pair of postocularia, and a small unpaired posterior plate, 166 long and 188 wide. Moreover, dorsum with six pair of platelets, two of these without glandularia. Anterolateral pair of platelets 275 long, lateral to unpaired anterior plate. Coxae in three groups, CxI+II fused medially. CxII and to a lesser extent CxIII elongated, apodemes of anterior coxae extending almost halfway medial margin of CxIV. Cxgl4 located near suture line of CxIII/IV. Posterior to CxIV a pair of large platelets, Cxgl3 not fused with the latter platelets. Genital field with three pairs of acetabula, 269 long (from anterior margin of pregenital sclerite to posterior margin of postgenital sclerite), 261 wide; genital plate 186 in length. Pregenital sclerite 166 wide, gonopore 144 long. Lateral to genital field four pairs of platelets, three of these with glandularia. Excretory pore sclerotized, posterior to genital field. Length of P15: 34, 101, 94, 94, 73. Palp as in male, but whiplike seta of P4 much longer than in male and with a truncate ventral extension, and P5 with a pair of spatulate setae located ventrally. Length of Ileg46: 119, 111, 109. Ileg5 anteroventrally with a somewhat blunt, stout seta. Length of IVleg46: 148, 153, 144.
Etymology. Named after the town of Moana.

Family Aturidae Thor
Subfamily Notoaturinae Besch Genus Abelaturus Cook, 1983 A monotypic genus known from New Zealand only. Cook, 1983 New records. North Island. 1/0/0, Kiriwhakapapa Stream, interstitial, Tararua  latter genus has no free glandularia (with the exception of one aberration), has the posteromedial dorsal plate with a tripartite ridge, the posterior extension of the dorsum is rugose and bearing the excretory pore, the acetabula are along the posterior margin of the venter, P2 is without denticles and P4 is without a ridge.

Abelaturus cornophorus
Asperaturus petiolatus n. sp. Genus Colobaturus Cook, 1991 A small genus with two species known from New Zealand.
Remarks. The examined female matches the original description by Cook (1983) except in more truncate gnathosomal bay (Fig. 17).
Distribution. Previously known from five localities from South Island (Smit 2017).
Remarks. The female of this study has a palp which differs from the typical uncipalpis palp (Fig. 18A). The specimen might belong to a new species, but due to the absence of a male, we refrain from describing it.
Distribution. Known from North and South Island. Cook, 1983 ( Figures 19AD, 28E Remarks. Thus far, the male was unknown, and therefore a description is given below.  short, stout setae. Length of IVleg46: 67, 75, 88.

Kritaturus (Kritaturus) vinnulus
Distribution. Previously known from two localities on South Island, and reported here for the first time from North Island. Diagnosis. Dorsum with two unpaired plates and two pairs of platelets, anterolateral platelets each with one glandularium, a "free" pair of glandularia present between posterior unpaired plate and the lateral platelets; the pair of glandularia between insertion of fourth legs and genital field closer to genital field; male gonopore trilobed.
Type species: Minyaturus minutulus n. sp. Etymology. Named for its small size, from the Greek minys.
Remarks. The new genus shares many characters with Pseudotryssaturus, like the dorsum with one pair of free glandularia. Pseudotryssaturus species usually have a ridge extending posteriorly from the insertion of the fourth leg (lacking in the new genus), although some species have a very short ridge or a ridge is lacking. Most Pseudotryssaturus species have the dorsum with some sort of ornamentation, but, as in the new genus, some species lack such ornamentation. But all male Pseudotryssaturus species have an ellipsoid or rounded gonopore, unlike the trilobed gonopore of the new species. Moreover, the idiosoma shape of Pseudotryssaturus species is elongated and not broad and tapering posteriorly as in the new genus. The pair of glandularia between the insertion of the fourth legs and the genital field are located halfway, and not closer to the genital field. Etymology. Named for its small size.

Genus Neotryssaturus Cook, 1983
A small genus with two species known from New Zealand.

Genus Paratryssaturus Cook, 1983
A genus with four species known from New Zealand. A fifth species is described below.

Paratryssaturus stewartensis Smit, 2017
New records. South Island.   Etymology. Named for its occurrence in the mountains.
Remarks. The male of the new species is distinguished easily from other Paratryssaturus species by the shape of IVleg5, in the other three species IVleg5 is rounded dorsally and not angular. The female of the new species is most similar to P. minutus (Hopkins) due to the position of the excretory pore near the posterior idiosoma margin, but the idiosoma of the new species is less slender, and the gonopore is more slender. However, the female of P. zodelus Cook is not known with certainty.
Paratryssaturus sp.   Remarks. The female described here might belong to a new species. However, due to the absence of a male, we refrain from naming it. Paratryssaturus cf. zodelus Cook, 1983 New records. South Island. 0/1/0, Graham River near outflow in Motueka River, 41°12.76 ′ S 172°50.0 ′ E, alt. 61 m asl, 10i2019.
Remarks. We identified this female based on the absence of papillae on the dorsum. However, due to the absence of a male, the identification is not certain.
Distribution. Previously recorded from the type locality on North Island only.
Genus Pilosaturus Cook, 1982 A monotypic genus known only from New Zealand.
Pilosaturus villosus (Hopkins, 1967)  Schwoerbelaturus aturoides (Schwoerbel, 1984)  Remarks. Thus far, the female was unknown, and therefore a description is given below. Description. Female: Idiosoma very weakly sclerotized, dorsally 234 long and 168 wide, ventrally 288 long. Dorsum with a large unpaired anterior plate with the postocularia, 93 long, 108 wide, and a slightly longer unpaired posterior plate with two pairs of glandularia and the excretory pore, 123 long and 109 wide. Moreover, dorsum with two pairs of lateral platelets, each platelet with a glandularium. Anterolateral platelet 116 long, posterolateral platelet 53 long. CxI projecting far anteriorly. Cxgl4 located near suture line of CxIII/IV. Posterior margin of CxIV obliterated. Projections associated with insertions of fourth legs rounded. Between insertions of fourth legs and genital field two pairs of glandularia, these more distanced from each other than in male. Genital field with numerous acetabula, one anterior pair distanced from the other acetabula; gonopore near posterior idiosoma margin, 27 long. Length of P15: 18, 34, 27, 63, 27 Remarks. The female matches the description of the genus well, only the leg segments of the fourth leg are less slender compared to the male. The location of this record, a large lake, seems atypical for the species. Very likely the species is hyporheic. There are several streams flowing into the lake, which may explain its occurrence in the lake.
Genus Taintaturus Cook, 1983 A genus with more than a dozen species known from New Zealand. Cook, 1983 New records. South Island. Remarks. Thus far, the male was unknown and a description is given below. The male matches the description of the female well, but P4 has a ridge which was not mentioned by Smit (2017)  Distribution. Previously known from the type locality on South Island only, and reported here from North Island as well.  Genus Zelandalbia Imamura, 1978 A small genus with four species known from New Zealand. Pesic & Smit, 2010 New record. South Island. 1/0/0, Monro Creek, interstitial, 30 km N of Haast, 43°42.882 ′ S 169°16.138 ′ E, alt. 17 m asl, 22xii2014; 1/0/0, Taipare Creek, interstitial, Taipare Bay, 41°00.977 ′ S 173°43.504 ′ E, alt. 9 m asl, 1i2019.

Zelandalbia longipalpis
Distribution. Previously known from several location in the Selwyn River.

Zelandopsis morimotoi
Distribution. Previously known from four localities, i.e. wells and interstitial habitats around Nelson.
Female: Unknown. Etymology. Named for its occurrence in New Zealand. Remarks. In the shape of P4 the new species is most close to the Penemideopsis phreatica from eastern Australia, with the seta nearly fused with the extension, only separated by a suture line. The two species from Western Australia have the seta of P4 distinct set off from the extension. The new species differs from the two species from Western Australia in a more bulging gonopore, a less far extending frontal margin and a straight posterior margin of CxIV (rounded in the two species from Western Australia). Penemideopsis phreatica Cook, 1986 has the idiosoma widened anteriorly (not widened in the new species) and Cxgl4 are lying much closer to the genital field than in the new species. Genus Anamundamella Cook, 1992 A monotypic genus known from New Zealand only.