The marine-associated lifestyle of ameronothroid (, ) and its evolutionary origin: a review Tobias Pfingstl,

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Tobias Pfingstl,. The marine-associated lifestyle of ameronothroid mites (Acari, Oribatida) andits evolutionary origin: a review. Acarologia, Acarologia, 2017, 57 (3), pp.693-721. ￿10.24349/acarolo- gia/20174197￿. ￿hal-01519742￿

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Acarologia is under free license and distributed under the terms of the Creative Commons-BY-NC-ND which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited. Acarologia 57(3): 693–721 (2017) DOI: 10.24349/acarologia/20174197

The marine-associated lifestyle of ameronothroid mites (Acari, Oribatida) and its evolutionary origin: a review

Tobias PFINGSTL

(Received 14 December 2016; accepted 21 March 2017; published online 05 May 2017; edited by Ekaterina SIDORCHUK)

Institute of Zoology, University of Graz, Universitätsplatz 2, 8010 Graz, Austria. pfi[email protected]

ABSTRACT — Existing literature on marine associated Ameronothroidea is reviewed and recapitulated. Although these littoral oribatid mites strongly resemble typical terrestrial mites, they have evolved different adaptions of various kinds to the marine littoral environment. In order to cope with intertidal wave action, most species show reduced and compact sensilla as well as sickle-shaped and elongated claws. Complex cerotegument based plastron mechanisms have evolved to allow breathing under flooded conditions and enabling these organisms to survive an average of more than a month completely submerged in saltwater. Behavioural adaptations include aggregations, diurnal and circatidal activity pat- terns, daily and seasonal migrations and thigmotaxis. Most taxa show no reproductive adaptions to the littoral habitat but some have developed ovoviviparity to protect the offspring and a few also have evolved distinct sexual dimorphism supposed to allow direct mating and secure sperm transfer in this constantly changing environment. Ameronothroid taxa are basically generalized feeders grazing on intertidal algae, and fungi which also serve as microhabitat. Coastal areas all over the globe have been colonized and these mites can be found in a wide range of habitats: e.g. polar shores, rocky coasts, sandy beaches, tropical mangrove forests, brackish river estuaries and salt marshes. The families show a distinct climate related distribution pattern, with the (Podacaridae included) in polar and cold temperate regions and the Fortuyniidae and Selenoribatidae in subtropical and tropical areas. Long distance transport to remote islands is supposed to be mainly achieved by bird phoresy in Ameronothridae and by dispersal via strong ocean currents in Fortuyniidae and Selenoribatidae. In literature there are basically two contrasting theories explaining the evolutionary invasion of marine associated habitats by ameronothroid mites, one favoring a monophyletic origin and a single land-to-sea transition event and another preferring an independent terrestrial ancestry and accordingly multiple invasions of the marine littoral environment. Recent molecular genetic studies support the latter theory and render the present superfamily of Ameronothroidea a polyphyletic taxon. KEYWORDS — adaptations; plastron; biogeography; behaviour; reproduction; convergence; Ameronothridae; Fortuyni- idae; Selenoribatidae

INTRODUCTION challenging the ability of organisms to cope with these extreme conditions. The marine intertidal zone constitutes one of the most interesting ecosystems on earth. It represents Very few groups have been able to accom- the border of two completely different worlds, the plish the land to sea transition, and they are scat- marine and the terrestrial realms, where environ- tered over various taxa. The prostigmatid Halacari- mental parameters are changing constantly, hence dae represent a group that has even managed to http://www1.montpellier.inra.fr/CBGP/acarologia/ 693 ISSN 0044-586-X (print). ISSN 2107-7207 (electronic) Pfingstl T. cross this line between land and sea completely characteristic elements of the marine littoral fauna. having radiated in marine waters. They are cos- The first member of this assemblage was discov- mopolitan, occurring from shallow waters to the ered more than 140 years ago (Thorell 1871), and bathyal and even the abyssal (e.g. Bartsch 2004) and since then three families, 17 genera and approxi- hence represent true marine organisms. Other mite mately 84 species have been described (Subías 2004, groups have not crossed this barrier, though they update 2016). Despite a large literature concern- have successfully invaded the littoral zone. ing diverse aspects of this substantial group, the present state of knowledge still shows many gaps, Among , some genera of the fam- relationships are largely unclear, and the evolution- ily Ologamasidae, for example Hydrogamasus and ary processes that led to the occupation of inter- Psammonsella, have adapted to intertidal marine tidal habitats are scarcely understood. Most of the habitats. Members of Halolaelapidae, e.g. Halo- literature is highly limited in scope, and only a laelaps and Halodarcia, are also known to inhabit few comprehensive studies include all members of littoral algae and beach wrack in coastal zones. Ameronothroidea (Wallwork 1964, Weigmann and Representatives of and are Schulte 1977, Behan-Pelletier 1997). likewise common predators in these habitats (e.g. Lindquist et al. 2009). The same applies to rep- The aim of the present paper is to summarize resentatives of the prostigmatid families Bdellidae, and synthesize existing literature on ameronothroid Rhagidiidae and (Walter et al. 2009). mites and to provide a concise and coherent Littoral species that forage on marine algae can also overview of the biological, ecological, zoogeo- be found in the endeostigmatic genus Nanorchestes, graphical and evolutionary aspects of the marine- and the whole astigmatine family Hyadesiidae is associated lifestyle of this taxon. Additionally, theo- composed of marine intertidal mites, occurring on ries about the evolutionary invasion of littoral habi- virtually all coastlines (e.g. Schuster 1979). Last, tats by ameronothroid mites are reviewed and eval- several isolated oribatid mite species, for example uated based on recent findings. Hermannia subglabra Berlese, 1910, Acrotritia clavata (Märkel 1964), Passalozetes bidactylus (Coggi, 1900), Punctoribates quadrivertex (Halbert, 1920), Halorib- MATERIALS AND METHODS atula tenareae Schuster, 1957 etc. are associated with marine shores; they are thalassophilous or tha- Data acquisition and illustrations lassobiont, meaning respectively that they occur Data presented in this paper are based on published in coastal areas or they have completely adapted literature, but some unpublished photographs, elec- to marine-associated environments (e.g. Schus- tron microscopic images and distribution maps ter 1957, 1966, 1979, 1989; Luxton 1967, Syamjith are added to illustrate various topics. Light pho- and Ramani 2013). Other than Halacaridae, all tographs were made with an Olympus E5 digital the above mentioned groups are examples of infre- SLR camera attached to either an Olympus BH-2 quent marine associations within larger evolution- microscope (for micrographs) or to an Olympus ary clades suggesting that the invasion of coastal SZX 12 stereo microscope (for normal photographs). habitats happened repeatedly and relatively re- Electron micrographs were taken at the Research In- cently in geological time. stitute for Electron Microscopy and Fine Structure Only one group of oribatid mites stands out Research, Graz, University of Technology (FELMI) as supposedly representing an ancient, mono- using a Leitz AMR microscope and a Zeiss Gem- phyletic taxon that evolved and radiated in ini Ultra 55. For this purpose specimens stored in the marine littoral environment, the superfamily 70% ethanol were dehydrated in ascending ethanol Ameronothroidea. More than 90% of oribatid mite concentrations, mounted on aluminium stubs with species living in intertidal habitats belong to this su- double-sided sticky tape, and then sputter coated perfamily (Proche¸sand Marshall 2001) and they are with gold–palladium.

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Terminology lifestyle of most members of this group was surely one of the main reasons for their unification, but Brachypyline classification used in this text fol- this motivation resulted in some ambiguous or con- lows the broad outlines of Norton and Behan- flicting taxonomic arrangements that are best under- Pelletier (2009). The term “Ameronothridae sensu stood in a historical context. stricto (s. str.)” refers to the northern hemispheric The first marine-associated oribatid mites were ameronothrid taxa (in the sense of Vitzthum 1942); discovered in the late nineteenth century, but were the more inclusive term “Ameronothridae sensu mostly classified in genera that have very differ- lato (s. l.)” refers to this northern hemispheric com- ent concepts today. Thorell (1871) described the ponent plus all southern hemispheric Podacaridae first ameronothroid mite, Ameronothrus lineatus (in (in the sense of Wallwork 1964). These terms are Eremaeus), from the polar Island Spitsbergen. In only used in the and Systematics Sec- subsequent years, further littoral species of mainly tion, in all other sections these groups are given polar and cold temperate coasts were found and as Ameronothridae and Podacaridae. A general described by the most renowned acarologists of overview of oribatid morphology is given by Nor- that time (e.g. L. Koch 1879, Michael 1882, Oude- ton and Behan-Pelletier (2009). mans 1903). Berlese proposed the first modern Species authors of all marine-associated ameronothroid genera, Ameronothrus (Berlese 1896) ameronothroid mites are given in Table 2 and there- and Halozetes (Berlese 1916) but included the former fore they are not cited when they are mentioned for in . Years later Willmann (1931) recog- the first time in text. However, species authors for nized that Ameronothrus represents an independent non-ameronothroid taxa are given in the text. taxon; accordingly Vizthum (1942) cited Willmann, 1931 as the family author. However, Willmann did TAXONOMYAND SYSTEMATICS –A BRIEF not mention the family name in his work and, fol- lowing the rules of the code of nomenclature, only HISTORICALOVERVIEW the author giving the name for the first time is to be At present, different classifications of the superfam- seen as the taxon author. Consequently, Vitzthum ily Ameronothroidea can be found in the literature (1942) is the author of Ameronothridae. In his essay (Table 1), and several taxonomic issues are still un- on the classification of oribatid mites, Grandjean resolved. However, all of these classifications (e.g. (1954) included Halozetes in Ameronothridae and Schulte and Weigmann 1977, Subías 2004, Norton confirmed the distinct status of this family. Only and Behan-Pelletier 2009 etc.) acknowledge the one year later, Grandjean (1955) described Podacarus Ameronothridae, Fortuyniidae and Selenoribatidae auberti, another littoral species from an Antarctic as ameronothroid families. The marine-associated island. He noted its systematic relationship to

TABLE 1: Four different classifications of the superfamily Ameronothroidea present in important publications on oribatid mite system- atics (indicated by different numbers). + family accepted as member, - rejected or neglected.

Author Ameronothroidea Ameronothridae s. l. Ameronothridae s. str. Podacaridae Fortuyniidae Selenoribatidae Tegeocranellidae Wallwork 1964 1 + + + + - Weigmann and Schulte 1977 2 + + + - Balogh and Balogh 1992 2 + + + - Behan-Pelletier 1997 3 + + + + Woas 2002 4 + + + + + Subías 2004 2 + + + - Norton and Behan-Pelletier 2009 3 + + + +

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Ameronothridae, but proposed the family Podacari- ered Thalassozetes riparius, another intertidal species dae based on divergent morphological features of from Mediterranean shores. Grandjean (1966) was the immatures of this species. Van der Hammen the first to give a detailed diagnosis for this fam- (1960) was the first to find an intertidal species in ily and later (Grandjean 1968) provided further tropical regions and included this new taxon, For- important taxonomic and systematic information tuynia marina, in Podacaridae. When van der Ham- strengthening the concept of Selenoribatidae. Since men (1963) proposed Fortuynia yunkeri, the second then the number of selenoribatid taxa quintupled species of this genus, he also described its juvenile and though there have been some problems at the stages; their morphology diverged conspicuously generic or species level (e.g. synonymies, unjusti- from juveniles of Podacaridae, and accordingly he fied transfers; for details see Pfingstl and Schuster excluded Fortuynia from this family and proposed 2012a), the family remained a well delimited and the family Fortuyniidae within Ameronothroidea. established monophyletic group. Shortly afterwards, Wallwork (1964) considered the The last and probably the most overlooked proposal of Fortuyniidae justified, and included ameronothroid family are the Tegeocranellidae only Podacarus, Alaskozetes and Halozetes in his re- which differ in their ecology from nearly all other vision of Podacaridae. Nevertheless, Balogh (1965) members in being exclusively associated with fresh- ignored these changes and assigned the genus For- water habitats. The distinctness of this monogeneric tuynia again to Podacaridae, regarding the obvious taxon was never questioned but the position within differences as only of generic significance. Lux- the system of higher oribatids and especially its in- ton (1967) disagreed with Balogh’s opinion and con- clusion within the Ameronothroidea is still contro- firmed again the validity of Fortuyniidae bringing versial. Balogh and Balogh (1992) included this this debate for now to an end; since then, Fortuyni- taxon initially in the Polypterozetoidea, a super- idae are commonly accepted as a distinct taxon of family characterized as eupheredermous Oribatida, Ameronothroidea. which means the nymphs retain the exuvial scalp of However, the discovery of further ameronothroid the preceding stage after the moult. But nymphs of species in subsequent years led to a controversy Tegeocranellidae do not retain scalps and are thus about the systematic status of Podacaridae and classified as apheredermous. Behan-Pelletier (1997) Ameronothridae. Based on detailed morphologi- noticed this fundamental mistake and moreover cal investigations, Schubart (1975) stated that these demonstrated plausibly that the family Tegeocranel- two families are likely to be two subfamilies of a lidae is indeed a member of the Ameronothroidea, single family. Weigmann and Schulte (1977) sup- closely related to Fortuyniidae and Selenoribatidae. ported Schubart’s hypothesis and included all for- Although Behan-Pelletier’s reasoning was based on mer podacarid genera in Ameronothridae arguing clear synapomorphic characters and thus conclu- that there is no decided gap among the taxa and that sive, several authors seem to have simply neglected their groupings into separate monophyletic families her excellent work. For example, in his annually up- are no longer justified. Some authors (Subías 2004, dated checklist of oribatid mites, Subías (2004) in- Norton and Behan-Pelletier 2009) accepted this tax- cludes the Tegeocranellidae in the superfamily Tec- onomic reorganization, others (Luxton 1990b, Woas tocepheoidea without any explanation and there- 2002) still recognized Podacaridae and so both sys- fore causes persisting confusion about the system- tematic groupings still are found in the literature. atic relationship of this family. The ameronothroid family Selenoribatidae, on In summary, a universally accepted system- the other hand, has never been seriously chal- atic concept of Ameronothroidea is lacking and lenged. Strenzke (1961) described the first selenori- certain groupings, e.g. Podacaridae included in batid species, Selenoribates foveiventris, from coasts Ameronothridae (Weigmann and Schulte 1977) or of the Red Sea, then Schuster (1963) proposed Tegeocranellidae included in Tectocepheoidea (Sub- two years later Selenoribatidae, when he discov- ías 2004), remain questionable.

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FIGURE 1: Global distribution of marine-associated ameronothroid mite families. Ameronothridae – blue circles; relictual terrestrial Ameronothridae – black circles; Selenoribatidae – orange circles; Fortuyniidae – red squares; Podacaridae – violet squares. Arrow- heads pointing to occurrences of taxa specifically discussed in the text. 1 – Alaskozetes coriaceus; 2 – Ameronothrus bilineatus; 3 – Aquanothrus; 4 – Chudalupia meridionalis.

BIOGEOGRAPHICDISTRIBUTION and are largely confined to Antarctic and Sub- Antarctic regions (Proche¸sand Marshall 2001). The Marine-associated Ameronothroidea can be found only occurrence outside these polar areas is that of in all oceans, and their distribution extends from Halozetes capensis, a possible endemic species living coasts of the Arctic to shores of the Antarctic on temperate shores of South Africa (Coetzee and (Figure 1). The occurrence of the families is Marshall 2003). strongly correlated with different climate zones, i.e. the Ameronothridae and Podacaridae are predom- The families of Fortuyniidae and Selenoribati- inantly contained within cold-temperate regions dae, on the other hand, are limited to shorelines around both poles (e.g. Proche¸sand Marshall 2001), of the subtropics and tropics (e.g. Schuster 1989) and only a small fraction of northern hemispheric and hence they appear to be warm-adapted mites. Ameronothridae can be found beyond the limits Most members can be found in the tropical East- of these areas. Ameronothrus bilineatus, A. mari- ern Pacific, the tropical Western Atlantic and the nus, A. schneideri and A. schusteri may occur to- Indo-Pacific (Proche¸s and Marshall 2001, Pfingstl wards the transition-zone to the tropics (Schulte and Schuster 2014) while the least inhabited area is 1975) though only A. maculatus clearly stands out the Mediterranean-Atlantic region. from the other cold-adapted taxa with records from Besides the aerial climate, a few authors (Schus- coasts of Tunisia (Schulte 1975) and the tropical ter 1966, Pfingstl and Schuster 2014, Pfingstl 2016) Caribbean Island Curaçao (Willmann 1936). suggested that the temperature of large ocean cur- In contrast to the northern hemispheric rents may also shape distributional patterns. For Ameronothridae, the southern hemispheric Po- example, warm-adapted selenoribatid mites occur dacaridae include exclusively cold-adapted taxa abundantly on the South American Atlantic coast

697 Pfingstl T. where the warm Brazil Current flows southwards, from Sub-Antarctic and Antarctic areas, where this whereas these mites are absent from the Pacific genus is abundant. Such a disjunctive distribution shore at the same latitudes where the cold Hum- on opposite Polar Regions, with more than 10 000 boldt Current prevails (Pfingstl and Schuster 2014). km in between, is more than extraordinary. It was A similar situation is found at the southern tip of suggested that the finding in Alaska may have been Africa: cold-adapted ameronothrid species occur on caused by migratory birds flying from Pole to Pole the west coast where the cold Benguela current is with the mites attached to their feathers (Schus- present, and warm-adapted fortuyniid and selenori- ter 1966). The second biogeographic puzzle was batid taxa inhabit the east coast where the warm Ag- the finding of Ameronothrus bilineatus specimens ulhas Current flows (Pfingstl 2016). from the littoral zone of South Africa (Weigmann However, aerial and oceanic climate are closely 1975b). Before that, this species was known to occur linked, and we do not know the relative importance only in the northern hemisphere, namely on Eu- of air or water temperature in the distribution of ropean coasts with a latitudinal distribution range these taxa. But given the fact that stenotopic inter- from Scandinavia to Portugal. Although Weigmann tidal species are spending half of their lives in the (1975b) mentioned the possibility of birds having seawater, it is likely that water temperature influ- transported specimens from Europe to South Africa, ences their biogeography. he favored the idea of a continuous distribution from Southern Europe along the African west coast. Although the worldwide distribution of Proche¸s and Marshall (2001), on the other hand, Ameronothroidea shows a relatively well-defined clearly classified the South African A. bilineatus pattern, two exceptional records have seemed enig- population as introduced, but offered no potential matic. The first is the discovery of Alaskozetes cori- explanation, so this biogeographic mystery also re- aceus (Hammer 1955) from an arctic hill in Alaska. mains unsolved. Marie Hammer described this species and proposed the genus Alaskozetes based on a single specimen that was given to her from that location. Surpris- Vast coastlines of each continent are still largely ingly, this was the only Alaskozetes specimen ever uncharted in terms of intertidal oribatid mite occur- found in the northern hemisphere, all others have rences and thus known biogeographic patterns may been collected later in the southern hemisphere change considerably in the future.

FIGURE 2: SEM-micrographs – juxtaposition of typical intertidal and typical terrestrial oribatid mites, showing no obvious differences (excepting tarsal claws much more prominent in intertidal species): A – Alismobates inexpectatus, inhabitant of rocky intertidal shores (Western Atlantic); B – Scutovertex ianus, found in moss (Central Europe).

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EVOLUTIONARY ADAPTATIONS TO THE most area of the littoral zone), like Ameronothrus lin- MARINELITTORALLIFESTYLE eatus or A. maculatus, in general have small sensilli while species dwelling in the intertidal zone, like A. Luxton (1990b) was correct in noting that marine- bilineatus and A. marinus, have lost their sensilli and associated oribatid mites appear at first sight to bothridia completely. A reduction of these sensory show no modifications for life on the sea shore. Be- organs may prevent overstimulation when the mite ing air-breathing that have not completely is submerged and subject to strong tidal wave ac- transgressed the ecological barrier between marine tion and constantly moving water. Indeed, the ma- and terrestrial environments, they strongly resem- jority of ameronothroid mites show relatively sim- ble typical terrestrial oribatid mites (Figure 2). Nev- ple and short sensilli. Members of the genus Fortuy- ertheless, evolutionary adaptations to the intertidal nia, which live in the lower eulittoral area (e.g. Pf- lifestyle can be found in all biological aspects of ingstl 2013b), exhibit especially short and compact these mites. sensilli.

(1) Morphology Another morphological trait affected by tidal wave action is the tarsal claws of the legs. Karasawa Daily tidal submergence is surely one of the main and Hijii (2004b) demonstrated that monodactylous selective factors shaping the morphology of inter- species dominate in littoral environments and con- tidal mites. Schubart (1971, 1975) noticed a causal sequently they stated that a reduction in the number correlation between frequent inundation and reduc- of claws may be an evolutionary adaptation to regu- tion of sensilli in the Ameronothridae. Species liv- lar tidal flooding. All members of Fortuyniidae and ing predominantly in supralittoral zones (the upper- Selenoribatidae, which are stenotopic inhabitants

FIGURE 3: Types of tarsal claws present in intertidal oribatid mites. Upper row – different kinds of elongated sickle-shaped claws, lower row – claws with additional teeth: A – Ameronothrus sp.; B – Fortuynia smiti; C – Selenoribatidae gen. nov.; D – Carinozetes bermudensis (one proximoventral tooth); E – Selenoribates arotroventer (two proximoventral teeth); F – Selenoribates satanicus (one proximoventral and one proximodorsal tooth).

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FIGURE 4: Photographs of flooded fortuyniid specimens from Bonaire Isl. Retained air can be seen as silvery shimmer on body surfaces. of the intertidal zone, show only a single claw on species dwelling on soft substrates (e.g. salt mead- their legs, whereas Ameronothridae and Podacari- ows, silted rocks) are monodactylous, accordingly dae, which have both intertidal and non-intertidal he postulated a correlation between type of substra- representatives, possess either one or three claws. tum and claw number. Apart from the claw number, Concerning the latter, Schubart (1975) noted that Pugh et al. (1987b) demonstrated that claws of inter- Ameronothrus species living on hard substrates (e.g. tidal Ameronothrus species are proportionally longer rocks, shore fortifications) are tridactylous, while than those of congeneric supralittoral species. In-

700 Acarologia 57(3): 693–721 (2017) deed, the majority of intertidal oribatid species pos- structures are absent and gas transfer is assumed to sesses elongated claws (Figure 3) allowing them to take place across the whole soft integument (Mess- grip the substrate more tightly during tidal flood- ner et al. 1992). ing (Karasawa and Hijii 2004b); these claws may be Adults of Fortuyniidae have furthermore equipped with spine-like structures (Figures 3D–F), evolved a unique complex system of lateral cutic- as in most selenoribatid species (e.g. Strenzke 1961, ular taenidia, also called van der Hammen’s organ Grandjean 1968, Pfingstl 2013c, 2015b). (e.g. Hammen 1963, Travé 1986, Pugh et al. 1990) (Figure 5). This system of taenidia connects the dor- (2) Plastron respiration sal and ventral plastron area and is thought to facili- tate rapid equilibrium of pressure changes between Intertidal ameronothroid mites are air-breathing an- the respiratory system and the surrounding envi- imals respiring with a tracheal system, therefore ronment caused by rough wave movements (Pugh they had to evolve special adaptations in order to et al. 1990). Although present in all fortuyniid mem- survive daily tidal flooding. Ameronothroid mites bers, the specific configuration of taenidia slightly are known to use plastron respiration when flooded. varies among the genera (e.g. Pfingstl and Schuster A plastron is an alternative respiration system ab- 2012b, Pfingstl and Krisper 2014). sorbing oxygen from the surrounding water via a Several authors investigated the efficiency of thin layer of air trapped by hydrophobic hairs or plastron respiration in certain ameronothroid taxa other cuticular projections (definition after Fielden and demonstrated that these mites are able to et al. 2011) and is known to occur in many aquatic survive astonishingly long periods of time under and semi-aquatic taxa, like insects and flooded conditions (Table 3). Alismobates inexpecta- spiders. Plastrons of intertidal ameronothroid mites tus, Fortuynia atlantica and Carinozetes bermudensis (Figure 4) are associated with cuticular and/or specimens survived an average of one month un- cerotegumental structures (e.g. Pugh et al. 1987a, der water (Pfingstl 2013a), A. lineatus and A. marinus 1990; Messner et al. 1992, Pfingstl and Krisper 2014). specimens more than two months (Schuster 1979, It was demonstrated by Pugh et al. (1987a) that the Pugh et al. 1987a) and A. maculatus tolerated in- cerotegument of Ameronothrus marinus contains ap- undation for more than one month (Schuster 1966). proximately 21 % airspace and that of A. maculatus Maximum survival times ranged from nearly two to even 60%. Although the air-retaining surface struc- eight months in these species (Schuster 1966, 1979; tures are more or less similar in all investigated taxa, Pfingstl 2013b). the specific mode of plastron respiration differs con- siderably among them. For example, in flooded for- (3) Behaviour tuyniid and selenoribatid adults the retained layer of air always communicates with the tracheal sys- Intertidal mites are confined to a relatively few mi- tem (Pfingstl and Krisper 2014), whereas in sub- crohabitats, such as rocky shore lichens, kelp hold- merged Ameronothrus individuals no such connec- fasts, etc., which provide protection from direct tion was found, and diffusion of oxygen from the and indirect stresses of severe wave action (Pugh plastron is assumed to occur across the weakly scle- and Mercer 2001), but behavioural adaptations rotized cuticle instead via the tracheae (Pugh et further minimize these stresses. Several marine- al. 1987b, 1990). Similarly, in juvenile Fortuyni- associated oribatid mites are relatively quick and idae and Selenoribatidae air is retained in certain active climbers (Pfingstl 2013a); this allows them to large lateral and ventral folds of the soft integument, escape rising tide and retreat into crevices or other and these folds are equipped with series of pores protected spots. There may be a relation among leading into tracheal structures supplying the inter- the speed of this locomotion, the substrate and the nal organs with oxygen (Pfingstl and Krisper 2014). mite’s vertical occurrence in the littoral area (Pfin- In Ameronothrus nymphs, on the other hand, the gstl 2013a). Species dwelling on rocky exposed sub- folding pattern is conspicuously different, tracheal strate in the lower eulittoral, such as F. atlantica, are

701 Pfingstl T.

FIGURE 5: SEM-micrograph of Fortuynia maledivensis, lateral view, demonstrating the configuration of Van der Hammen’s organ. Arrows point to each lateral cuticular channel of this organ; Ss – sensillus, la – lateral anterior notogastral seta, I–III – legs. very fast climbers (Pfingstl 2013a), while species liv- mary function of this behaviour, but in some in- ing in the upper and more vegetated eulittoral area, stances aggregations may aid mate location (Block e.g. Halozetes otagoensis, Ameronothrus schneideri and and Convey 1995) and synchronization of moults , are moderate or even slug- (Søvik 2004). gish runners (Luxton 1966, 1990a, Strong 1967, God- dard 1979). The more exposed and closer the ani- Certain fortuyniid and selenoribatid species mals are to the water’s edge, the more quickly they show thigmotactic behaviour (Pfingstl 2013a) by en- must react and move to avoid being washed away. tering narrow crevices and small depressions when these are present. This behaviour is advantageous Another behavioural strategy to prevent dis- in a periodically flooded environment because it lodgement by waves is aggregation. This has been limits the time the animals spend in open areas, ex- observed often and in many intertidal taxa, e.g. posed to the tidal surge. Intertidal oribatid mites Fortuyniidae (Krisper and Schuster 2008, Pfingstl usually are either inactive (e.g. Schulte 1973, Behan- 2013a), Ameronothridae (Schulte et al. 1975, Schulte Pelletier and Eamer 2007) or show low activity 1976b, Bücking et al. 1998, Søvik 2004) and Po- when flooded (Pfingstl 2013a). Pugh and King dacaridae, (Peckham 1967, Goddard 1979, Convey (1986) demonstrated that intertidal mites have activ- 1994b) where hundreds of individuals of different ity cycles synchronized with diurnal and circatidal age are crouched next to and on top of each other patterns, so that they are most active during peri- (Figure 6A). Protection against wave action is a pri- ods of low tide and bright daylight. Individuals of

702 Acarologia 57(3): 693–721 (2017)

FIGURE 6: Photographs illustrating characteristic behaviors intertidal Fortuynia atlantica: A – Adult specimens aggregating in a small depression of substrate; B – Three adults and rafting on water surface – “floating behavior” (white rings on mites are reflections of ring-light illuminator).

A. marinus even perform rhythmic daily vertical mi- (4) Reproduction grations to avoid tidal flooding. In this way, they re- duce the time of submergence and extend the time As noted, aggregation may facilitate finding mates of possible food intake (Schulte 1973). (Block and Convey 1995) or deposition of eggs in areas far above tidal range (Bücking et al. 1998), The temperate species A. lineatus shows another but there are several other reproductive traits that interesting strategy to reduce or avoid the mechan- have evolved as adaptations to the marine environ- ical stress of wave movement. In summer, when ment. For example, most Ameronothridae are ovo- reproduction reaches its peak, adults migrate into viviparous (for a detailed discussion of this phe- the uppermost eulittoral where they lay eggs; off- nomenon see Norton 1994), with the larva having spring develop there for the next two months, then developed within the mother’s body and hatching deutonymphs move back to the littoral zone where from the egg immediately (larviparity) or within a development is completed (Bücking et al. 1998). By few hours after deposition (Luxton 1966, Weigmann these seasonal vertical migrations the dangers of the 1975a, Bücking et al. 1998, Søvik 2003, Søvik et tidal cycle are avoided for at least the most vulnera- al. 2003). This way, the vulnerable egg stage ble stages: eggs, larvae and protonymphs. is extremely shortened and the mobile larva can promptly escape tidal waves. The tropical For- tuyniidae and Selenoribatidae, on the other hand, Despite these strategies, intertidal mites surely are oviparous; their egg stage takes approximately are surprised often by waves and washed away, and 15–35 days, similar to those of typical terrestrial ori- for such an event the tropical F. atlantica has evolved batid mites (Pfingstl 2013a). However, they protect an interesting behaviour. When exposed to a sud- their eggs from tidal movement by either gluing den flood, specimens immediately splay the legs, so them into tiny crevices of the substrate, as for ex- that they float like a raft on the surface of the water ample in F. atlantica, or they push them deep into until they again reach firm substrate (Pfingstl 2013a) the intertidal algae so that the algal mass completely (Figure 6B). By this so-called “floating behaviour” encloses and protects the eggs, e.g. as in A. inexpec- the mites increase their chances of survival in the tatus (Pfingstl 2013a). open water and successful dispersal by ocean cur- rents (Pfingstl 2013a). Spermatophores of males appear even more

703 Pfingstl T.

FIGURE 7: Examples of distinct sexual dimorphism littoral ameronothroid mites (see text for explanation): A – Alaskozetes antarcticus (modified after Wallwork 1962); B – Fortuynia atlantica (modified after Krisper and Schuster 2008); C – Fortuynia dimorpha (modified after Pfingstl 2015a). fragile structures that are easily destroyed by fications of the fourth leg (Hammen 1963) but males the mechanical effects of the tides, but no spe- of F. atlantica possess certain lanceolate notogastral cial littoral adaptations are known, which Al- setae, enlarged notogastral porose areas and a pair berti (1974) already demonstrated for Trombid- of obvious lateral protuberances on the notogaster iformes. Typical stalked spermatophores were (Krisper and Schuster 2008); in males of F. dimorpha found in Ameronothridae (Luxton 1966, Schuster the posterior part of the gastronotic region is com- 1979, Søvik 2004), Fortuyniidae and Selenoribati- pletely covered with a porose area and several noto- dae (Pfingstl 2013a). Pfingstl (2013a) suggested gastral setae are conspicuously elongated (Pfingstl that spermatophore deposition, detection and uti- 2015a). The function of these modified characters lization by females may happen quickly during the is unknown but if they are linked to dermal glands short time frame of low tide. In this way sper- like the octotaxic system of brachypyline mites (Al- matophores would not come in contact with water berti et al. 1997, Norton and Alberti 1997, Norton and hence would be safe. et al. 1997) and porose areas of mixonomatid Col- (Norton and Sidorchuk 2014), they Distinct sexual dimorphism is present in a small probably play a role in semiochemical communica- percentage of ameronothroid species, where it is tion linked with associative mating (Pfingstl 2015a, expressed to different degrees and in various re- Behan-Pelletier 2015). Although never observed, gions of the body (Pfingstl 2015a, Behan-Pelletier direct sperm transfer in the littoral environment and Eamer 2010, Behan-Pelletier 2015) (Figure 7). In would be clearly advantageous because it reduces A. lineatus and A. nigrofemoratus, males exhibit con- the stress for the sperm package in this intermit- spicuously longer legs than females (e.g. Schubart tently dry and wet habitat. 1975) whereas in the podacarid species Podacarus auberti, Halozetes belgicae and Alaskozetes antarcticus However, at least two fortuyniid species have males show a remarkable aggenital neotrichy which managed to completely avoid the stress of tidal is absent in females (e.g. Wallwork 1964). Not a inundation on spermatophores by simply not pro- single case of sexual dimorphism is known in se- ducing them. In Fortuynia hawaiiensis and For- lenoribatid mites, whereas a handful of fortuyniid tuynia maledivensis males are completely absent species have elaborate sexually dimorphic charac- and females reproduce via thelytoky (Pfingstl and ters. Fortuynia yunkeri males show only slight modi- Jagersbacher-Baumann 2016). This reproductive

704 Acarologia 57(3): 693–721 (2017) mode entails a few advantages because it reduces and type of food can also be observed, accordingly: costs of producing males, mate finding and sperm (1) inhabitants of rocky intertidal shores predomi- transfer in the extreme conditions of intertidal envi- nantly feed on epilithic algae (algivorous), (2) mites ronments and furthermore it facilitates the coloniza- dwelling on hard substrates in supralittoral areas tion of new coastlines. prefer lichens (lichenivorous) and (3) species occur- ring in salt marshes mostly graze on fungi (fungiv- (5) Feeding orous) (Schulte 1976b). Feeding activity and defecation of Ameronothrus As far as known, marine-associated oribatid mites species follow a tidal rhythm, with maxima be- are generalized feeders with various degrees of spe- tween the high tides (Schulte 1976b, Pugh and King cialization (e.g. Schulte 1979, Pfingstl 2013a), and 1986). This suggests that they feed as much as pos- usually the substrate serves them both a habitat sible during low tide and then rest during high tide (or protection against desiccation and dislodgment) when they are submerged. Schulte (1976a) demon- and a food source (Bücking et al. 1998, Pfingstl strated that inhabitants of the lower eulittoral, ex- 2013a) (Figure 8). Most Ameronothridae, Podacari- posed to longer periods of submergence, start feed- dae and several Fortuyniidae and Selenoribatidae ing earlier and feed more quickly during low tide have been observed feeding on diverse types of than do populations of the upper eulittoral, which green algae, as for example the microphytes Pleu- are subject to shorter periods of inundation and rococcus sp. or Chlorococcus sp., the filamentous al- hence have more time to feed. gae Lyngbia sp. or Rhizoclonium riparium, macro- phytes Enteromorpha sp. or Prasiola crispa and sea- (6) Physiology weed Porphyra sp. (Peckham 1967, Schulte 1976b, Pugh 1995, Pfingstl 2013a). Lichens are also an im- There is a large amount of literature – enough to fill portant food source for intertidal mites (e.g. Block a book – dealing with physiological adaptations of and Convey 1995), but the mites feed predomi- ameronothroid mites but more than 90 % of it fo- nantly on the phycobionts, i.e. the algal cells, of cuses on the ability of Antarctic Podacaridae to sur- the lichens (e.g. Schulte 1976b, Bücking et al. 1998). vive the extreme low temperatures and conditions In some cases Ameronothrus species were reported of polar areas. These studies (e.g. Sømme and Block to feed on fungi (Luxton 1966, Schulte 1976b). Cer- 1984, Convey 1994a, Block and Convey 1995, Wor- tain fortuyniid and selenoribatid species as well as land and Lukešová 2000, Worland and Convey 2001, the ameronothrid A. maculatus are known to pri- Deere and Chown 2006, Hawes et al. 2007, Benoit marily graze on cyanobacteria (Schuster 1979, Søvik et al. 2008) are important to understand the mech- 2004, Krisper and Schuster 2008). Carnivory has anisms of survival in such cold environments, but not yet been confirmed in any intertidal oribatid studies investigating physiological adaptations to species. Schuster (1977) once inferred that Selenori- the marine environment are few, so our knowledge batidae may be carnivorous as he found pieces of is sketchy. tardigrades in their guts, but soon after he withdrew Intertidal oribatid mites are resistant to salt and his idea (Schuster 1979). fresh water and as mentioned above, they can sur- Food preferences may differ among the de- vive inundation for weeks and sometimes months velopmental stages (Luxton 1966). Adults and (e.g. Schuster 1979, Pfingstl 2013b) (Table 3). How tritonymphs of most Ameronothrus species feed on osmoregulation works in these animals is unclear micro- and macroalgae, while the larvae, proto- and but probably they possess the ability of hypertonic deutonymphs feed exclusively on microalgae. This regulation to water of lower osmotic values than sometimes leads to a spatial separation of the stages, their hemolymph, such as fresh water, and to water with the younger ones staying in higher littoral ar- of higher values, i.e. salt water, they are probably eas (Schulte 1976b, Bücking et al. 1998). In most poikilosmotic (Schuster 1979). It has been suggested Ameronothrus species a correlation between habitat that littoral mites use their coxal glands for os-

705 Pfingstl T.

FIGURE 8: Algal habitat as substrate and food resource: A – Intertidal alga Bostrychia sp. growing on mangrove root (El Limón, Domini- can Republic). B – Enlarged view of Bostrychia sp. showing Alismobates inexpectatus individuals foraging on alga and depositing fecal pellets. moregulation (Alberti and Storch 1977) or that they km upstream from the Mediterranean coast (Travé reduce ion resorption from excretory waste filtrate if 1963). Some members of Ameronothridae can also their coxal glands are degenerated (Woodring 1973). be found far inland in typical terrestrial habitats, as for example the high arctic Ameronothrus lapponicus HABITATS AND ECOLOGY (Dalenius 1963) or the Scandinavian Ameronothrus dubinini, which was discovered a few kilometers in- Ameronothroid mites have colonized various mi- land (Laine et al. 1988). Within the littoral envi- crohabitats of the marine littoral, even though ronment, Ameronothridae may occur on sediment- this represents only a spatially restricted habitat. free rocky coasts (e.g. Bücking et al. 1998), on Ameronothridae and Podacaridae show various de- sediment-rich hard substrates (e.g. Schulte et al. grees of association with the intertidal ecosystem, 1975), in salt-marshes (e.g. Luxton 1966) and in including (1) typical intertidal species, e.g. A. mari- washed-ashore flotsam or tidal debris (e.g. Schulte nus; (2) so-called transition species, able to dwell in et al. 1975, Pugh and MacAlister 1994). There are both environments, e.g. A. lineatus; and (3) typical also reports of quite unusual habitats. For example, terrestrial species, as for example P. auberti (Schulte the Antarctic Alaskozetes antarcticus was found near and Weigmann 1977) (see Table 2). There is a dis- seal wallows or around penguin rookeries (Peck- tinct latitudinal component to this habitat speci- ham 1967, Block and Convey 1995) but also on dead ficity: species at lower latitudes in each hemisphere birds and well-rotted seal carcasses (Goddard 1979); are restricted to littoral environments while species Ameronothrus lineatus was collected from the nests found at higher latitudes show a greater affinity for of three different seabirds on Spitsbergen (Coulson terrestrial habitats (Schulte et al. 1975, Marshall and et al. 2009) and Antarcticola georgiae and Halozetes Convey 2004). Furthermore, several northern hemi- belgicae were sampled from whale bones on sub- sphere Ameronothridae are also able to colonize Antarctic coasts (e.g. Goddard 1979, Pugh and brackish and freshwater habitats, such as marine MacAlister 1994). Independent of microhabitat and ponds and estuaries (e.g. Schulte et al. 1975). Espe- taxon, investigations have shown that intertidal and cially A. maculatus shows high freshwater tolerance terrestrial species show generally high niche speci- and can frequently be found on the shores of coastal ficity whereas transition species are eurytopic and rivers (e.g. Schulte et al. 1975, Schuster 1986); in may occur in a wide range of niches (Schulte et al. one case individuals were found in a small river 50

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1975, Marshall et al. 1999). are lacking in these taxa. Collectively, Selenoribati- dae species may inhabit a wide variety of intertidal In contrast to Ameronothridae and Podacaridae, habitats, e.g. sandy beaches, boulder beaches, rocky the subtropical and tropical Fortuyniidae and Se- cliffs and mangrove roots (e.g. Karasawa and Aoki lenoribatidae are stenotopic inhabitants of the lit- 2005, Pfingstl 2013a). Mangrove forests are one of toral area, i.e. transition species or terrestrial species

TABLE 2: List of predominantly marine-associated ameronothroid species and their ecological classification. *associated with aquatic and/or terrestrial habitats; transition = occurring from the littoral to terrestrial areas, intertidal = restricted to the eulittoral zone; ? no information available.

Taxon ecological class Ameronothridae Ameronothrus bilineatus (Michael, 1888) intertidal A. dubinini Sitnikova, 1975 terrestrial A. lapponicus Dalenius, 1963 terrestrial A. lineatus (Thorell, 1871) transition A. maculatus (Michael, 1882) transition A. marinus (Banks, 1896) intertidal A. nidicola Sitnikova, 1975 transition A. nigrofemoratus (Koch, 1879) transition A. oblongus Sitnikova, 1975 transition A. schneideri (Oudemans, 1903) intertidal A. schubarti Weigmann & Schulte, 1975 intertidal A. schusteri Schubart, 1970 intertidal Aquanothrus montanus Engelbrecht, 1975 terrestrial* Chudalupia meridionalis Wallwork, 1981 terrestrial* Podacaridae Antarcticola meyeri (Wallwork, 1967) terrestrial Alaskozetes antarcticus (Michael, 1903) transition A. bouvetoyaensis Pletzen & Kok, 1971 transition A. coriaceus Hammer, 1955 terrestrial Halozetes bathamae Luxton, 1984 intertidal H. belgicae (Micheal, 1903) transition H. capensis Coetzee & Marshall, 2003 intertidal H. crozetensis (Richters, 1908) transition H. edwardensis Pletzen & Kok, 1971 intertidal H. fulvus Engelbrecht, 1975 terrestrial H. impeditus Niedbała, 1986 transition H. intermedius Wallwork, 1963 intertidal H. littoralis Wallwork, 1970 intertidal H. maquariensis (Dalenius, 1958) terrestrial H. marinus (Lohmann, 1907) intertidal H. marionensis Engelbrecht, 1974 intertidal H. necrophagus Wallwork, 1967 transition H. otagoensis Hammer, 1966 transition H. plumosus Wallwork, 1966 transition H. scotiae (Trouessart, 1912) ? Podacarus auberti Grandjean, 1955 terrestrial Pseudantarcticola georgiae (Wallwork, 1970) terrestrial

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TABLE 2: Continued.

Taxon ecological class Fortuyniidae Alismobates inexpectatus Pfingstl & Schuster, 2012 (2012b) intertidal A. keniaensis Pfingstl, 2016 intertidal A. pseudoreticulatus Pfingstl, 2015 (2015c) intertidal A. reticulatus Luxton, 1992 intertidal A. rotundus Luxton, 1992 intertidal Circellobates venustus Luxton, 1992 intertidal Fortuynia arabica Bayartogtokh, Chatterjee, Chan & Ingole, 2009 intertidal F. atlantica Krisper & Schuster, 2008 intertidal F. dimorpha Pfingstl, 2015 (2015a) intertidal F. elamellata Luxton, 1967 intertidal F. hawaiiensis Pfingstl & Jagersbacher-Baumann 2016 intertidal F. inhambanensis Marshall & Pugh, 2002 intertidal F. longiseta Pfingstl, 2015 (2015c) intertidal F. maculata Luxton, 1986 intertidal F. maledivensis Pfingstl, 2015 (2015c) intertidal F. marina Hammen, 1960 intertidal F. rotunda Marshall & Pugh, 2002 intertidal F. sinensis Luxton, 1962 intertidal F. smiti Ermilov, Tolstikov, Mary & Schatz, 2013 intertidal F. taiwanica Bayartogtokh, Chatterjee, Chan & Ingole, 2009 intertidal F. yunkeri Hammen, 1963 intertidal Selenoribatidae Arotrobates granulatus Luxton, 1992 intertidal A. lanceolatus Luxton, 1992 intertidal Carinozetes bermudensis Pfingstl & Schuster, 2012 intertidal C. mangrovi Pfingstl, Lienhard & Jagersbacher-Baumann, 2014 intertidal C. trifoveatus Pfingstl & Schuster, 2012 intertidal Psednobates uncunguis Luxton, 1992 intertidal Rhizophobates shimojanai Karasawa & Aoki, 2005 intertidal Schusteria littorea Grandjean, 1968 intertidal S. melanomerus Marshall & Pugh, 2000 intertidal S. nagisa Karasawa & Aoki, 2005 intertidal S. saxea Karasawa & Aoki, 2005 intertidal S. ugraseni Marshall & Pugh, 2000 intertidal Selenoribates arotroventer Pfingstl, 2015 (2015b) intertidal S. asmodaeus Pfingstl, 2015 (2015b) intertidal S. divergens Pfingstl, 2015 (2015b) intertidal S. elegans Pfingstl, 2013 (2013c) intertidal S. foveiventris Strenzke, 1961 intertidal S. ghardaqensis Abd-el-Hamid, 1973 intertidal S. mediterraneus Grandjean, 1966 intertidal S. niccus Pfingstl, 2015 (2015b) intertidal S. quasimodo Pfingstl, 2013 (2013c) intertidal S. satanicus Pfingstl, 2013 (2013c) intertidal Thalassozetes barbara Pfingstl, 2013 (2013d) intertidal T. riparius Schuster, 1963 intertidal T. tenuisetosus Bayartogtokh & Chatterjee, 2010 intertidal

708 Acarologia 57(3): 693–721 (2017) the most important environments for tropical inter- mites have also reached geologically young and tidal oribatid mites (Karasawa and Hijii 2004a) and remote oceanic islands clearly shows that there are some species, e.g. Carinozetes mangrovi, seem to be other ways of dispersal. There are several disper- exclusively associated with these habitats (Pfingstl sal mechanisms that may be responsible for long- et al. 2014). Fortuyniidae species, on the other hand, distance transport of these flightless , display a very narrow range of habitats. Nearly but the scarcity of evidence has allowed no con- all of them inhabit rocky shores; only three out of sensus on their reality or relative importance. An 20 species have been reported to occur occasionally overview of these possible dispersal mechanisms in mangrove forests (e.g. Pfingstl 2015c). Pfingstl follows. (2015c) suggested that the homogeneous morphol- ogy of the genus Fortuynia may be associated with (1) Anthropogenic dispersal seems unlikely as this limited habitat preference. Several Fortuynia intertidal mites do not occur on commercially species may also dwell in empty barnacles or oys- used or soils. Although the transport of ter shells, and are the only intertidal mites known these mites in bilge tanks of large vessels can- to do so (Hammen 1963; Aoki 1974; Luxton 1990a, not be excluded, shipping activities are recent in 1992; Marshall and Pugh 2002; Krisper and Schus- geological times and may not have seriously in- ter 2008). There is one record of F. smiti found in fluenced present distribution and population pat- a riverine environment which represents the most terns. Nevertheless, with growing globalization unusual occurrence of this taxon (Pfingstl 2015c). activities this mode of dispersal may well have an impact on patterns in the near future.

DISPERSALMECHANISMS (2) Aerial dispersal (anemochory) is another possible mechanism but experimental data on this Given the strong ecological connection of topic are rare and controversial. In an early study ameronothroid mites to the littoral zone habitat, (Glick 1939), in which insect traps were installed dispersal by active migration would be possible on airplanes, mites were trapped on various occa- only along the coastline, but the fact that these sions at different altitudes, but nearly all trapped

TABLE 3: Observed survival times of ameronothroid mites experimentally submerged in salt water. LT 50 = median lethal time, max = maximum survival time.

LT 50 max reference Ameronothridae s. str. Ameronothrus lineatus 74 days / > 2 months 249 days / > 8 months Schuster 1979 A. maculatus - 104-108 days / > 3 months Schuster 1966 43 days / > 1 month 160 days / > 5 months Schuster 1979 A. marinus - 138 days / > 4 months Schuster 1966 68 days / > 2 months 143 days / > 4 months Schuster 1979 Podacaridae Halozetes marinus >20 / < 1 month - Pugh 1995 Fortuyniidae Alismobates inexpectatus 21 days / < 1 month 55 days / > 1 month Pfingstl 2013a Fortuynia atlantica 40 days / > 1 month 143 days / > 4 months Pfingstl 2013a Selenoribatidae Carinozetes bermudensis 19 days / < 1 month 51 days / > 1 month Pfingstl 2013a

709 Pfingstl T. specimens belonged to phoretic mite taxa that use dispersal by birds was met. Nevertheless, the insects as transport hosts. In a later study (Gres- same study could find no evidence of the mites sitt and Yoshimoto 1974), using fine meshe aerial being actually transported the by birds. Pugh nets in Alaska, a few oribatid mites were caught (1997) dismissed a priori bird-mediated trans- drifting in the wind, and a more recent study port of oribatid mites to oceanic islands, argu- (Lehmitz et al. 2011) demonstrated that oribatid ing that mites dispersed by birds usually show mites can be dispersed by wind up to at least specific morphological adaptations to attach to 160 m above ground level, though the majority of the bird’s body. Marine-associated ameronothroid these wind-transported mites consisted of species mites show no morphological modification for usually found in tree habitats. In contrast, a sim- phoresy, though their long hook-like claws may ilar survey found no evidence of wind dispersal facilitate such transport. While transport in bird of mites (Coulson et al. 2003). Moreover, power- plumage remains a possible, if improbable, disper- ful storms would be necessary to propel flightless sal mechanism for Ameronothridae, it almost cer- arthropods long distances of a few thousand kilo- tainly has no role for Fortuyniidae or Selenoribati- meters and even if this would happen, these an- dae: species of these exclusively intertidal fami- imals would not survive the extreme conditions, lies do not dwell in the vicinity of seabird nests such as low pressure and freezing temperatures or colonies. at high altitudes (Pugh 2003). Intertidal oribatid mites are neither phoretic on insects, nor do they (4) Another potential method to reach remote inhabit trees and therefore aerial dispersal is a islands is through transport by ocean currents (hy- quite unlikely mode of long-distance transport for drochory). First evidence was provided by a study them. in which pleuston nets on boat trips between the islands of the Galápagos archipelago were used af- (3) Bird-mediated transport has been discussed ter a heavy storm, and a remarkable number of liv- as another possible way of reaching and coloniz- ing oribatid mite individuals was found floating ing remote islands (e.g. Schatz 1991, 1998; re- in debris or directly in the sea (Peck 1994). To sur- view by Lebedeva and Lebedev 2008) but again, vive such a transport, tolerance of long periods of evidence is scarce and authors are of different submersion is necessary, which littoral mites pos- minds as to the importance of this mode of dis- sess, as discussed above (e.g. Schuster 1979, Pugh tribution. In a long-term study of birds in po- et al. 1987a). Coulson et al. (2002) further demon- lar areas, several terrestrial mites were found on strated that even terrestrial arthropods with dif- a few occasions, either in bird nests or plumage ferent biologies are able to survive in salt water (Lebedeva and Lebedev 2008, Lebedeva 2012) and for over 14 days and therefore transoceanic dis- hence birds are believed by these authors to be the persal by mites and collembolans may be a com- main suppliers of soil mites to isolated archipela- mon phenomenon. Based on mean survival times gos. of Bermudian intertidal oribatid mite species, indi- Considering the terrestrial nature of high Arc- viduals are able theoretically to survive transport tic and Antarctic Ameronothridae, it is indeed pos- in seawater along the Gulf Stream over a distance sible that dispersal occasionally occurs in this way. of 3,000 km (Pfingstl 2013b). Moreover, the float- For example, it would explain the already men- ing behaviour of certain Fortuynia species (Pfin- tioned mysterious findings of Alaskozetes coriaceus gstl 2013a) as well as the possession of buoyancy- and Ameronothrus bilineatus in hemispheres oppo- giving plastrons in supposedly all ameronothroid site from their main distributions (Schuster 1966, taxa, would contribute to their hydrochorous dis- Weigmann 1975b). In the above-mentioned study persal. Therefore, most authors (e.g. Schatz 1991, of seabird nesting colonies on Spitsbergen, A. lin- 1998; Coulson et al. 2002; Pfingstl 2013b) agree eatus individuals were found in a few nests (Coul- that long-distance dispersal of oribatid mites to son et al. 2009), hence the basic prerequisite for oceanic islands is mainly hydrochorous.

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EVOLUTIONOFTHEINTERTIDAL a terrestrial ancestor of ameronothrid mites, inhab- LIFESTYLE iting cold and wet soils, occupied larger portions of the world’s land masses and a warming of the An extensive fossil record since the Middle Devo- world’s atmosphere scattered these animals to cooler nian (388 ± 3,8 mya) indicates that oribatid mites locations. Subsequent glaciation events pushed are an ancient taxon (Norton et al. 1988). A molecu- these mites closer to the shore and finally forced lar genetic study (Schaefer et al. 2010) even suggests them to invade polar coastlines. The chances of that oribatid mites were among the first terrestrial survival were higher near the warmer sea and so colonizers and had already originated in the Pre- these coastal species radiated in the littoral envi- (571 ± 37 mya). The colonization of land ronment and spread along the coast to warmer cli- started in the interstitial zone of coastal habitats and mates and this spreading happened independently finally resulted in the occupation of all terrestrial in the Northern and Southern hemisphere. Marshall habitats on earth. Marine-associated mites as well and Convey (2004) agreed that all ameronothroid lin- as the exclusively marine halacarid mites demon- eages must ultimately have had an earlier terrestrial strate that some of them not just evolved from water ancestry but they argued that at least recent colo- to land but later also from land to water. nization patterns of podacarid mites of the south- ern hemisphere cannot be explained with the afore- Current hypotheses mentioned hypothesis. They stated that species liv- ing exclusively in intertidal habitats of the Antarctic Schuster (1966) was the first to theorize about the and Sub-Antarctic are more primitive than those in origin of the intertidal lifestyle in oribatid mites. He supralittoral/terrestrial environments of coastal ar- suggested two possible ways: (a) terrestrial ances- eas and proposed that colonization by ameronothrid tors successively colonized the fringe of freshwater (podacarid) mites in the southern hemisphere has bodies, then brackish water habitats and finally the proceeded from marine habitats to terrestrial areas marine littoral; (b) fully terrestrial ancestors began to following glacial retreat. However, a molecular ge- feed on washed-ashore flotsam, rich in organic mat- netic investigation of several Antarctic species of Po- ter, and subsequently specialized on other food re- dacaridae (Halozetes, Alaskozetes, Podacarus) found no sources present in the intertidal zone. Schuster ad- evidence of speciation from an intertidal to a terres- mitted that both scenarios could have been concur- trial group or vice versa (Mortimer et al. 2011). Al- rent, but considered it more likely that at least the though the above-mentioned theories (Schuster 1966, Ameronothridae took the former evolutionary path- Schulte and Weigmann 1977, Marshall and Convey way. Indeed, certain members of Ameronothrus can 2004) offer different opinions on recent evolutionary be found regularly in estuaries (e.g. Schulte et al. patterns, all agree on a monophyletic origin of the 1975) and can withstand long periods of inundation Ameronothroidea and their littoral lifestyle. not only with salt water but also with fresh water (Schuster 1979). Pfingstl (2013b) also discovered an Proche¸s (2001), on the other hand, suggested unexpectedly high fresh water tolerance in the exclu- that land-to-sea transition in secondary marine or- sively intertidal selenoribatid Carinozetes bermudensis ganisms, including ameronothroid mites, took place and suggested it may be a relictual trait. A high gen- independently in three distinct latitudinal bands eral water tolerance was without a doubt a preadap- (northern cold-temperate, tropical, southern cold- tation necessary for mites to invade aquatic habitats, temperate) (Figure 9B). He suggested that species but it provides no evidence of evolutionary pathway, interactions, i.e. competition, drove the origin since some typical terrestrial species, e.g. Euzetes glob- of marine association in subtropical and tropical ulus, also can tolerate long periods of inundation selenoribatid and fortuyniid mites, while glacia- (Schuster 1966). tion is thought to be responsible for that of polar Schulte and Weigmann (1977) provided another ameronothrid/podacarid mites (e.g. Schulte and evolutionary scenario (Figure 9A) hypothesizing that Weigmann 1977, Proche¸sand Marshall 2001).

711 Pfingstl T.

FIGURE 9: Simplified schemes illustrating two different evolutionary theories explaining origin of marine-associated Ameronothroidea: A – Monophyletic origin of Ameronothroidea implying single land-to-sea transition event (e.g. supported by Schulte and Weigmann 1977); B – Polyphyletic Ameronothroidea and three independent invasions marine littoral (e.g. supported by Proche¸s2001). T = last terrestrial ancestor, invading littoral environment. (Schemes are not to be seen as phylogenetic trees, length of lines does not correspond with time or number of evolutionary changes).

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Flaws in current hypotheses, and evidence from groupings and that the current disjunct distribu- preliminary molecular studies tion, in opposite areas of the world, may not be associated with the relictual occurrences of Aquan- Schulte and Weigmann (1977) provided a thought- othrus and Chudalupia. The biogeographic pat- ful hypothesis concerning the monophyletic origin tern of Ameronothroidea rather supports the the- of the intertidal lifestyle which lead to the taxo- ory of Proche¸s (2001), in which land-to-sea tran- nomic unification of Ameronothridae and Podacari- sitions took place independently in three distinct dae. The authors plausibly demonstrated that there latitudinal bands, with the Ameronothridae in the are not enough morphological features separating northern cold-temperate, the Fortuyniidae and Se- these two taxa and indeed, presently there are only lenoribatidae in the tropical, and the Podacari- two characters which do not overlap: the presence dae in the southern cold-temperate region. This in all Ameronothrus species (but absence in all Po- theory is further supported by results of Krause dacaridae) of brachytracheae in legs and the ab- et al. (2016) who investigated the evolution of sence of setae it on leg IV of all Podacaridae (versus aquatic life by oribatid mites using molecular genet- the presence in Ameronothridae). From a morpho- ics. They concluded that Fortuyniidae and Selenori- logical point of view, the monophyly of this group batidae colonized salt water habitats only once seemed to be validated. whereas the Ameronothridae invaded these habi- However, the molecular genetic study of Schäf- tats independently and hence they suggested that fer et al. (2010), encompassing selected oribatid Ameronothroidea are a polyphyletic taxon. mite species from diverse families, including A. mac- Behan-Pelletier and Eamer (2007) argued that ulatus and P. auberti, demonstrated a paraphyletic the evolution of respiratory organs in Oribatida was position of the two taxa, which clearly contradicts a critical step in the invasion of aquatic habitats, the conclusion of Weigmann and Schulte (1977). and indeed the development of plastron respira- Wallwork (1964) had already argued that certain tion was surely one of the most important adap- similar traits of the Podacaridae and Ameronothri- tations allowing the colonization of the intertidal dae may have evolved independently. Both taxa zone. Comparing plastron respiration systems in inhabit predominantly cold and temperate regions Ameronothroidea further supports the theory of in- and similar environmental properties may have led dependent land-to-sea transition events. Fortuyni- to similar convergent morphologies. The biogeo- idae and Selenoribatidae use similar plastrons and graphic distribution of Ameronothridae and Po- breathe with tracheal organs while submerged (Pf- dacaridae – in opposite hemispheres without a note- ingstl and Krisper 2014), whereas Ameronothridae worthy overlap – may point to an independent use different plastron organs and breathe across the origin rather than to a common ancestry. The thin weakly sclerotized cuticle during submergence two often neglected and exceptional monotypic (Pugh et al. 1987a, 1990; Messner et al. 1992). genera Aquanothrus and Chudalupia, occurring in ephemeral rock pools at modest elevations in semi- In summary, biogeographic, molecular genetic arid or arid regions of North America, South Africa and plastron respiration data contradict the theory and Western Australia, have been considered relict- of a monophyletic Ameronothroidea in its current ual ameronothrid species (Norton et al. 1997) that sense, and suggest multiple independent origins of might have been linked biogeographically in the their marine-associated lifestyle. distant past. But there is evidence from another Nevertheless, biogeographic patterns are largely molecular genetic study (Mortimer et al. 2011) that incomplete and many new taxa and occurrences Aquanothrus is not closely related to Podacaridae as remain to be found (Pfingstl and Schuster 2014). the ceratozetoid genus Magellozetes intervenes be- Furthermore, the recent molecular genetic studies tween Aquanothrus and the Podacaridae. Conse- (Schäffer et al. 2010, Mortimer et al. 2011, Krause quently, these data also indicate that Ameronothri- et al. 2016), while informative, are certainly pre- dae and Podacaridae are supported as different liminary, as they include very few ameronothroid

713 Pfingstl T. taxa and concentrated on different research ques- colonized the marine littoral either by migrating tions. Finally, plastron structures were investigated downstream into brackish waters or by inhabiting in very few species, none of which was a member of coastal freshwater bodies that eventually became Podacaridae. connected to the open ocean and evolved there to the Fortuyniidae and Selenoribatidae. The semiaquatic Tegeocranellidae and their relationship to marine-associated mites CONCLUDINGREMARKS

Several authors (e.g. Subías 2004, Marshall Ameronothroid intertidal oribatid mites have suc- and Pugh 2002) do not accept the monogeneric cessfully colonized all shorelines, from biologically Tegeocranellidae as a member of Ameronothroidea depauperate ice-cold polar coasts to lush humid because they do not consider the juvenile mor- tropical shores. Although air-breathing and simi- phology to be important for systematic considera- lar in overall morphology to typical terrestrial taxa, tions. Given the above-mentioned doubts about the they have evolved specific adaptations to the ma- monophyly of Ameronothroidea, it may seem rea- rine littoral, as for example modified tarsal claws, sonable to agree with these authors. Nonetheless, plastron respiration and ovoviviparity. Daily tidal Behan-Pelletier (1997) provided seven synapomor- cycles and associated wave action are the most phies supporting a relationship among Tegeocranel- important stress factors shaping these adaptations. lidae, Fortuyniidae and Selenoribatidae. The most Hydrochorous dispersal is considered the main obvious synapomorphy is certainly the shared type long-distance transport mechanism in fortuyniid of juvenile plication, namely a centrodorsal gas- and selenoribatid mites, whereas bird-mediated tronotic plate framed by deep lateral and ventral transport may be responsible for dispersal events in folds and wrinkles, only present in immatures of northern ameronothrid mites. these three taxa. Pfingstl and Krisper (2014) demon- strated that this specific type of plication plays an Based on recent findings it is suggested that the important role in plastron respiration of juvenile for- families currently included in Ameronothroidea do tuyniid and selenoribatid mites. Though not inves- not share a proximate common ancestry. They prob- tigated yet in tegeocranellid immature stages, they ably have colonized coastal environments at least may use the same plastron mechanism and this three times, once in northern hemispheric polar and could be a further indication of a common origin. temperate areas by the Ameronothridae, once in the Another morphological character associated with Tropics by ancestors of Fortuyniidae and Selenorib- plastron respiration may also support a close re- atidae and once in Antarctic and Sub-Antarctic re- lationship between Tegeocranellidae and Fortuyni- gions by the Podacaridae. Accordingly, the family idae. The already-mentioned van der Hammen’s Ameronothridae sensu lato – i.e. sensu Weigmann organ of fortuyniid mites is part of the plastron and Schulte (1977) – is a polyphyletic grouping, and system, and Behan-Pelletier (1997) noticed similar the unification of Ameronothridae with Podacari- structures in Tegeocranellidae but refrained from dae no longer seems justified. The two families considering these traits homologous. Consider- probably evolved parallel in opposite Polar regions. ing a close relation between Tegeocranellidae and The Fortuyniidae, Selenoribatidae and Tegeocranel- Fortuyniidae/Selenoribatidae, occupation of semi- lidae, on the other hand, may still represent a mono- aquatic freshwater habitats may represent the more phyletic lineage which has evolved from a tropical ancestral ecology. Based on these indications, the ancestor that already showed an association with following scenario might be considered: a terres- freshwater habitats. trial ancestor colonized semiaquatic and aquatic As Marshall and Convey (2004) already pointed freshwater habitats, e.g. ponds and streams, then out, a more complete understanding of the evolu- some descendants diversified within these environ- tion of marine-associated mites will require thor- ments, evolving the Tegeocranellidae, and others ough morphological and molecular phylogenetic in-

714 Acarologia 57(3): 693–721 (2017) vestigations. Moreover, a comprehensive and holis- Balogh J., Balogh P. 1992 — The Oribatid Mites Genera of tic approach is needed to reveal natural relation- the world. Vol. 1 — Hungarian Natural History Mu- ships among alleged members of Ameronothroidea seum: Budapest. pp. 263. and to reconstruct their evolutionary pathway from Banks N. 1896 —New North American spiders and mites — Transact. Amer. Entomol. Soc., 23: 57-77. a terrestrial ancestor to the sea. Bartsch I. 2004 — Geographical and ecological distribu- tion of marine halacarid genera and species (Acari: ACKNOWLEDGEMENTS Halacaridae) — Exp. Appl. Acarol., 34: 37-58. doi:10.1023/B:APPA.0000044438.32992.35 This work was funded by the Theodor-Körner Bayartogtokh B., Chatterjee T. 2010 — Oribatid mites Fund, therefore my sincerest thanks go to this from marine littoral and freshwater habitats in India with remarks on world species of Thalassozetes (Acari: Fund and its sponsors; in difficult times when Oribatida) — Zool. Stud., 49: 839-854. I considered abandoning my scientific career, I Bayartogtokh B., Chatterjee T., Chan B.K.K., Ingole B. was awarded with the prestigious Theodor-Körner 2009 — New species of marine littoral mites (Acari: prize, which firstly gave me enough confidence to Oribatida) from Taiwan and India, with a Key to the continue my research and secondly supported me world’s species of Fortuynia and notes on their distri- financially to perform the present studies. My work butions — Zool. Stud., 48: 243-261. would not have been possible without this support. Behan-Pelletier V.M. 1997 — The semiaquatic genus Thanks also to G. Krisper for contributing interest- Tegeocranellus (Acari: Oribatida: Ameronothroidea) of ing ideas, thoughts and pictures. Special thanks to North and Central America — Can. Entomol., 129: 537-577. doi:10.4039/Ent129537-3 Roy A. Norton for providing numerous construc- Behan-Pelletier V.M. 2015 — Review of sexual dimor- tive comments and for helping to improve the qual- phism in brachypyline oribatid mites — Acarologia, ity of this work. I also want to thank the Centre for 55: 127-146. Electron Microscopy Graz (FELMI) and its team for Behan-Pelletier V.M., Eamer B. 2007 — Aquatic Oribatida: realizing the electron micrographs. Adaptations, constraints, distribution and ecology — In: Morales-Malagara J.B., Behan-Pelletier V.M., Ueck- ermann E., Pérez T.M., Estrada-Venegas E.G., Badii M. REFERENCES (Eds.). Acarology XI: Proceedings of the International Congress. México: Instituto de Biología and Facultad Abd-el-Hamid M.E. 1973 — Acari (Oribatei) aus Ägypten: de Ciencias, Universidad Nacional Autónoma de Méx- Selenoribates ghardaqensis nov. sp. am Roten Meer — ico; Sociedad Latinoamericana de Acarología. p. 71- Anz. österr. Akad. Wiss., mathemat. naturwiss. Kl., 8: 82. 53-56. Behan-Pelletier V.M., Eamer B. 2010 — The first sexually Alberti G. 1974 — Fortpflanzungsverhalten und dimorphic species of Oribatella (Acari, Oribatida, Ori- Fortpflanzungsorgane der Schnabelmilben (Acarina: batellidae) and a review of sexual dimorphism in the Bdellidae, ) — Z. Morph. Tiere, 78: — Zootaxa, 2332: 1-20. 111-157. doi:10.1007/BF00298469 Benoit J.B., Yoder J.A., Lopez-Martinez G., Elnitsky M.A., Alberti G., Storch V. 1977 — Zur Ultrastruktur der Cox- Lee Jr. R.E., Denlinger D.L. 2008 — Adaptations for aldrüsen actinotricher Milben — Zool. Jb. Anat., 109: the maintenance of water balance by three species 394-425. of Antarctic mites — Polar Biol., 31: 539-547. doi:10.1007/s00300-007-0385-9 Alberti G., Norton R.A., Adis J., Fernandez N.A., Franklin E.N., Kratzmann M., Moreno A.I., Weigmann G. and Berlese A. 1896 — Acari, Myriapoda et Scorpiones hu- Woas S. 1997 — Porose integumental organs of orib- cusque in Italia reperta. Ordo Cryptostigmata II (Orib- atid mites (Acari, Oribatida). 2. Fine structure — Zoo- atidae) — Padua: Portici. pp. 98. logica, Stuttgart, 146, 33–114. Berlese A. 1910 — Acari nuovi. Manipoli V-VI — Redia, Aoki J. 1974 — The first record of the intertidal Oribatid 6, 199-234. genus, Fortuynia, from Asia — Annot. Zool. Jpn., 47(3), Berlese A. 1916 — Centuria prima di Acari nuovi — Re- 170–174. dia, 12: 19-67. Balogh J. 1965 — A synopsis of the world Oribatid (Acari) Block W., Convey P. 1995 — The biology, life cycle genera — Acta Zool. Hung., 11: 5-99. and ecophysiology of the Antarctic mite Alaskozetes

715 Pfingstl T.

antarcticus — J. Zool., London, 236: 431-449. islands Gough and Marion — Navors. Nas. Mus., doi:10.1111/j.1469-7998.1995.tb02723.x Bloemfontein, 3: 53-88. Bücking J., Ernst H., Siemer F. 1998 — Population dynam- Ermilov S.G., Tolstikov A.V., Mary N., Schatz H. 2013 — ics of phytophagous mites inhabiting rocky shores – Oribatid mites (Acari, Oribatida) from riverine envi- K-strategists in an extreme environment? — In: Eber- ronments of some islands in Oceania — Zookeys, 318: mann E. (Ed.). Arthropod Biology: Contributions to 47-57. Morphology, Ecology and Systematics. Biosystemat- Fielden L.J., Knolhoff L.M., Villarreal S.M., Ryan P. 2011 — ics and Ecology Series 14. Vienna: Österreichische Underwater survival in the dog vari- Akademie der Wissenschaften. p. 93-143. abilis (Acari: ) — J. Insect Physiol., 57: 21-26. Coetzee L., Marshall D.J. 2003 — A new Halozetes species doi:10.1016/j.jinsphys.2010.08.009 (Acari: Oribatida: Ameronothridae) from the marine Glick P.A. 1939 — The distribution of insects, spiders and littoral of southern Africa — African Zool., 38: 327- mites in the air — Tech. Bull., 673: 1-151. 331. Goddard D.G. 1979 — Biological observations on the free- Coggi A. 1900 — Nuovi Oribatidi Italiani — Bullettino living mites of Signy Island in the maritime Antarctic della Societa Entomologica Italiana, (30), 309–324. — Brit. Antarct. Surv. Bull., 49: 181-205. Convey P. 1994a — Growth and survival strategy of the Grandjean F. 1954 — Essai de classification des Oribates Antarctic mite Alaskozetes antarcticus — Ecography, 17: (Acariens) — Bull. Soc. Zool. France, 78: 421-446. 97-107. Grandjean F. 1955 — Sur un acarien des iles Kerguelen. Convey P. 1994b — Sex ratio, oviposition and early de- Podacarus auberti (Oribates) — Mém. Mus. Nat. Hist. velopment of the Antarctic oribatid mite Alaskozetes Natur. Paris, 8: 109-150. antarcticus (Acari: Cryptostigmata) with observations Grandjean F. 1966 — Selenoribates mediterraneus n.sp. et les on other oribatids — Pedobiologia, 38: 161-168. Selenoribatidae (Oribates) — Acarologia, 8: 129-154. Coulson S.J., Hodkinson I.D., Webb N.R., Harrison J.A. Grandjean F. 1968 — Schusteria littorea n.g., n.sp. et les 2002 — Survival of terrestrial soil-dwelling arthropods Selenoribatidae (Oribates) — Acarologia, 10: 116-150. on and in seawater: implications for trans-oceanic dis- Gressitt J.L., Yoshimoto C.M. 1974 — Insect dispersal persal — Funct. Ecol., 16: 353-356. doi:10.1046/j.1365- studies in Northern Alaska — Pac. Insects, 16: 11-30. 2435.2002.00636.x Halbert J.N. 1920 — The acarina of the seashore — Pro- Coulson S.J., Hodkinson I.D., Webb N.R. 2003 — Aerial ceedings of the Royal Irish Academy, 35(B), 106–152. dispersal of invertebrates over a high-Arctic glacier Hammen van der L. 1960 — Fortuynia marina gen. nov., foreland: Midtre Lovénbreen Svalbard — Polar Biol., sp. nov., an oribatid mite from the intertidal zone in 26: 530-537. doi:10.1007/s00300-003-0516-x Netherlands New Guinea — Zool. Meded., 37: 1-9. Coulson S.J., Moe B., Monson F., Gabrielsen G.W. 2009 Hammen van der L. 1963 — Description of Fortuynia — The invertebrate fauna of High Arctic seabird nests: yunkeri nov. spec., and notes on the Fortuyniidae nov. the microarthropod community inhabiting nests on fam. — Acarologia, 5: 152-167. Spitsbergen, Svalbard — Polar Biol., 32: 1041-1046. doi:10.1007/s00300-009-0603-8 Hammer M. 1955 — Alaskan Oribatids — Acta Arctica, 7: 5-36. Dalenius P. 1963 — Studies on the Oribatei (Acari) of the Torneträsk territory in Swedish Lapland. V. Some in- Hammer M. 1966 — Investigations on the oribatid fauna teresting species — Ark. Zool., 16: 1-8. of New Zealand — K. Dan. Vidensk. Selsk. Biol. Skr., 15: 1-108. Dalenius P., Wilson O. 1958 — On the soil fauna of the Hawes T.C., Bale J.S., Worland M.R., Convey P. 2007 — Antarctic and of the Sub-Antarctic Islands. The Orib- Plasticity and superplasticity in the acclimation poten- atidae (Acari) — Ark. Zool., 11: 393-425. tial of the Antarctic mite Halozetes belgicae (Michael) — Deere J.A., Chown S.L. 2006 — Testing the beneficial J. Exp. Biol., 210: 593-601. doi:10.1242/jeb.02691 acclimation hypothesis and its alternatives for loco- Karasawa S., Aoki J. 2005 — Oribatid Mites (Arachnida: motor performance — Amer. Nat., 168: 630-644. Acari: Oribatida) from the Marine Littoral of the doi:10.1086/508026 Ryukyu Archipelago, Southwestern Japan — Species Engelbrecht C.M. 1974 — The genus Halozetes (Oribatei: Div., 10: 209-233. Acari) on Marion Island — Navors. Nas. Mus., Bloem- Karasawa S., Hijii N. 2004a — Effects of microhabitat fontein, 3: 1-25 diversity and geographical isolation on oribatid mite Engelbrecht C.M. 1975 — New ameronothroid (Oribatei: (Acari: Oribatida) communities in mangrove forests — Acari) taxa from the Republic of South Africa and the Pedobiologia, 48: 245-255.

716 Acarologia 57(3): 693–721 (2017)

Karasawa S., Hijii N. 2004b — Morphological modifica- Luxton M. 1986 — A new species of Fortuynia (Acari: tions among oribatid mites (Acari: Oribatida) in rela- Cryptostigmata) from the marine littoral of Kenya — J. tion to habitat differentiation in mangrove forests — Nat. Hist., 20: 65-69. doi:10.1080/00222938600770061 Pedobiologia, 48: 383-394. Luxton M. 1990a — Local distribution and habitat of Koch L. 1879 — Arachniden aus Sibirien und Novaya mites (Acari) on the sea coast of New Zealand Zemlya, eingesammelt von der Schwedischen Expedi- — J. Royal Soc. New Zeal., 20: 419-426. tion im Jahre 1875 — Kong. Sv. Vet. Akad. Handl., 16: doi:10.1080/03036758.1990.10426720 3-136. Luxton M. 1990b — The marine littoral mites of the New Krause A., Pachl P., Schulz G., Lehmitz R., Seniczak Zealand region — J. Royal Soc. New Zeal., 20: 367-418. A., Schaefer I., Scheu S., Maraun M. 2016 — Conver- doi:10.1080/03036758.1990.10426719 gent evolution of aquatic life by sexual and partheno- Luxton M. 1992 — Oribatid mites from the marine littoral genetic oribatid mites — Exp. Appl. Acarol., 70: 439¬- of Hong Kong (Acari: Cryptostigmata) — In: Morton 453. B. (Ed.). The marine flora and fauna of Hong Kong and southern China III. Proceedings of the Fourth In- Krisper G., Schuster R. 2008 — Fortuynia atlantica ternational marine Biological Workshop: The marine sp. nov., a thalassobiontic oribatid mite from the Flora and Fauna of Hong Kong and Southern China. rocky coast of the Bermuda Islands (Acari: Orib- Hong Kong: Hong Kong University Press. p. 211–227. atida: Fortuyniidae) — Ann. Zool., 58: 419-432. doi:10.3161/000345408X326753 Märkel K. 1964 — Die Jacot 1930 und ihre Gattungen (Acari, Oribatei) — Zoologische Ver- Laine A., Orell M., Itämies J. 1988 — The distribution and handelingen, Leiden, 67, 3–78. ecology of the mite Ameronothrus dubinini Sitnikova, Marshall D.J., Convey P. 2004 — Latitudinal variation 1977 (Acarina, Oribatei) in northern Finland — Ann. in habitat specifity of ameronothroid mites (Orib- Zool. Fenn., 25: 253-256. atida) — Exp. Appl. Acarol., 34: 21-35. Lebedeva N.V. 2012 — Oribatid mites transported by doi:10.1023/B:APPA.0000044437.17333.82 birds to polar islands — In: Hempel G., Lochte K., Marshall D.J., Gremmen N.J.M., Coetzee L., OConnor Matlshov G. (Eds) Arctic marine biology. Bremer- B.M., Pugh P.J.A., Theron P.D., Ueckermann E.A. haven: Helmholtz Gemeinschaft. p. 152-161. 1999 — New records of Acari from the sub-Antarctic Lebedeva N.V., Lebedev R. 2008 — Transport of oribatid Prince Edward Islands — Polar Biol., 21: 84-89. mites to polar areas by birds — In: Bertrand M., Kre- doi:10.1007/s003000050338 iter S., McCoy K.D., Migeon A., Navajas M., Tixier M- Marshall D.J., Pugh P.J.A. 2000 — Two new species of S., Vial L. (Eds) Integrative Acarology. Montpellier: Schusteria (Acari: Oribatida: Ameronothroidea) from Euraac. p. 359-367. marine shores in southern Africa — Afr. Zool., 35: 201- Lehmitz R., Russel D., Hohberg K., Christian A., Xylan- 205. doi:10.1080/15627020.2000.11657091 der W.E.R. 2011 — Wind dispersal of oribatid mites as Marshall D.J., Pugh P.J.A. 2002 — Fortuynia (Acari: Ori- mode of migration — Pedobiologia, 54: 201-207. batida: Ameronothroidea) from the marine littoral of southern Africa — J. Nat. Hist, 36: 173-183. Lindquist E.E., Krantz G.W., Walter D.E. 2009 — Order doi:10.1080/00222930010002775 Mesostigmata — In: Krantz G.W., Walter D.E. (Eds). A manual of Acarology – Third edition. Texas: Texas Messner B., Adis J., Franklin Ribeiro E. 1992 — A Tech University Press p. 430-564. comparative study on plastron structures in mites (Acari) — Dtsch. Entomol. Z., 39: 159-176. Lohmann H. 1907 — Die Meeresmilben der Deutschen doi:10.1002/mmnd.19920390124 Südpolar-Expedition 1901-1903 — In: Drygalski E. Michael A.D. 1882 — Further notes on British Oribatidae (Ed). Deutsche Südpolar-Expedition 1901-1903. Berlin, — J. Royal Microsc. Soc., London, 2: 1-18. Reimer Verlag. p. 361-413. Michael A.D. 1888 — British Oribatidae. Vol. 2 — Lon- Luxton M. 1966 — Laboratory studies on the feeding don: Ray Society. pp. 337-657. habits of saltmarsh Acarina, with notes on their behav- ior — Acarologia, 8: 163-174. Michael A.D. 1903 — Acarina (Oribatidae). Expedition Antarctique Belge. Resultats du Voyage du S.Y. Belgi- Luxton M. 1967 — Two new mites from the rocky shore cae n 1897-1898-1899 — Rap. Sci. Zool., 10: 1-6. of North Auckland — New Zeal. J. Mar. Fresh. Res., 1: Mortimer E., Jansen van Vuuren B., Lee J.E., Marshall D.J., 76-87. doi:10.1080/00288330.1967.9515194 Convey P., Chown S.L. 2011 — Mite dispersal among Luxton M. 1984 — More marine littoral mites from New the Southern Ocean Islands and Antarctica before the Zealand — New Zeal. J. Marine Freshw. Res., 18: 291- last glacial maximum — Proc. Royal Soc. B, 278: 1247- 302. doi:10.1080/00288330.1984.9516051 1255. doi:10.1098/rspb.2010.1779

717 Pfingstl T.

Niedbała W. 1986 — Several species of moss-mites (Acari, ogy and hydrochorous dispersal — Exp. Appl. Ac- Oribatida) from the Antarctic coastal zone — Pol. Po- arol., 61: 87-96. doi:10.1007/s10493-013-9681-y lar Res., 7: 119-126. Pfingstl T. 2013c — Revealing the diversity of a once Norton R.A.1994 — Evolutionary aspects of oribatid mite small taxon: the genus Selenoribates (Acari, Orib- life histories and consequences for the origin of the atida, Selenoribatidae) — Zookeys, 312: 39-63. Astigmata — In: Houck M. (Ed.). Mites. Eco- doi:10.3897/zookeys.312.5478 logical and evolutionary analyses of life history pat- Pfingstl T. 2013d — Thalassozetes barbara n. sp. (Acari, Ori- terns. New York: Chapman and Hall. p. 99-135. batida), a new intertidal species from the coast of Bar- doi:10.1007/978-1-4615-2389-5_5 bados — Acarologia, 53: 417-424. Norton R.A. and Alberti G. 1997 — Porose integumental organs of oribatid mites (Acari, Oribatida). 3. Evolu- Pfingstl T. 2015a — An interesting case of sexual dimor- Fortuynia dimorpha tionary and ecological aspects — Zoologica, Stuttgart, phism in intertidal mites: sp. nov. 146, 115–143. (Acari, Oribatida, Fortuyniidae) — Syst. Appl. Ac- arol., 20: 567-578. doi:10.11158/saa.20.5.10 Norton R.A., Alberti G. and Woas S. 1997 — Porose in- tegumental organs of oribatid mites (Acari, Oribatida). Pfingstl T. 2015b — Morphological diversity in Selenorib- 1. Overview of types and distribution. — Zoologica, ates (Acari, Oribatida): new species from coasts of the Stuttgart, 146, 1–31. Red Sea and the Indo-Pacific — Int. J. Acarol., 41: 356- 370. doi:10.1080/01647954.2015.1035321 Norton R.A., Behan-Pelletier V.M. 2009 — Suborder Orib- atida — In: Krantz G.W., Walter D.E. (Eds). A manual Pfingstl T. 2015c — The intertidal Fortuyniidae (Acari: of Acarology – Third edition. Texas: Texas Tech Uni- Oribatida): new species, morphological diversity, ecol- versity Press. p. 430-564. ogy and biogeography — Zootaxa, 3957: 351¬-382. Norton R.A., Bonamo P.M., Grierson J.D., Shear W.A. Pfingstl T. 2016 — Marine associated mites (Acari: 1988 — Oribatid mite fossils from a terrestrial Devo- Oribatida: Ameronothroidea) of the African conti- nian deposit near Gilboa, New York — J. Palaeontol., nent: biogeography, new species and distribution 62: 259-269. doi:10.1017/S0022336000029905 records — Syst. Appl. Acarol., 21: 320-334. doi:10.11158/saa.21.3.7 Norton R.A., Graham T.B., Alberti G. 1997 — A rotifer- eating ameronothroid (Acari: Ameronothridae) mite Pfingstl T., Jagersbacher-Baumann J. 2016 — Indica- from ephemeral pools on the Colorado Plateau — In: tions of parthenogenesis and morphological differen- Mitchell R., Horn J., Needham G.R., Welbourn W.C. tiation in Hawaiian intertidal Fortuynia (Acari, Ori- (Eds). Acarology IX, Proceedings of the IXth Interna- batida) populations — Zool. Anz., 260: 11-24. tional Congress of Acarology. Columbus: Ohio Bio- doi:10.1016/j.jcz.2015.11.004 logical Survey. p. 539-542. Pfingstl T., Krisper G. 2014 — Plastron respiration in ma- Norton R.A. and Sidorchuk E.A. 2014 — Collohmannia rine intertidal oribatid mites (Acari, Fortuyniidae and johnstoni n. sp. (Acari, Oribatida) from West Virginia Selenoribatidae) — Zoomorphology 133: 359-378. (U.S.A.), including description of ontogeny, setal vari- doi:10.1007/s00435-014-0228-5 ation, notes on biology and systematics of Collohman- Pfingstl T., Schuster R. 2012a — Carinozetes nov. gen. niidae — Acarologia, 54(3), 271–334. (Acari: Oribatida) from Bermuda and remarks on the Oudemans A.C. 1903 — Notes on the Acari. Fifth series present status of the Family Selenoribatidae — Ac- — T. Entomol., 45: 123-150. arologia, 52: 377-409. Peck S.B. 1994 — Sea-surface (pleuston) transport of in- Pfingstl T., Schuster R. 2012b — First record of the littoral sects between islands in the Galápagos Archipelago, genus Alismobates (Acari: Oribatida) from the Atlantic Ecuador — Ann. Entomol. Soc. America, 87: 576-582. ocean, with a redefinition of the family Fortuyniidae doi:10.1093/aesa/87.5.576 based on adult and juvenile morphology — Zootaxa, Peckham V. 1967 — Studies of the Mite Alaskozetes antarcti- 3301: 1-33. cus (Michael) — Antarct. J. U.S., 2: 196-197. Pfingstl T., Schuster R. 2014 — Global distribution of Pfingstl T. 2013a — Habitat use, feeding and re- the thalassobiontic Fortuyniidae and Selenoribatidae productive traits of rocky-shore intertidal mites (Acari, Oribatida) — Soil Organisms, 86: 125-130. from Bermuda (Oribatida: Fortuyniidae and Se- Pfingstl T., Lienhard A., Jagersbacher-Baumann J. 2014 — lenoribatidae) — Acarologia, 53: 369-382. Hidden in the mangrove forest: the cryptic intertidal doi:10.1051/acarologia/20132101 mite Carinozetes mangrovi sp. nov. (Acari, Oribatida, Pfingstl T. 2013b — Resistance to fresh and salt water in in- Selenoribatidae) — Exp. Appl. Acarol., 63: 481-495. tertidal mites (Acari: Oribatida): implications for ecol- doi:10.1007/s10493-014-9802-2

718 Acarologia 57(3): 693–721 (2017)

Pletzen R., Kok D.J. 1971 — Oribatei — In: Zinderen molecules and fossils in oribatid mites (Acari, Ori- Bakker E.M., Winterbottom J.M., Dyer R.A. (Eds). Mar- batida) — M. Phylogenet. Evol., 57: 112-121. ion and Prince Edward Islands. Cape Town: A.A. doi:10.1016/j.ympev.2010.04.015 Balkema. p. 314-326. Schäffer S., Koblmüller S., Pfingstl T., Sturmbauer C., Proche¸s S. 2001 — Back to the sea: secondary ma- Krisper G. 2010 — Ancestral state reconstructions rine organisms from a biogeographical perspective — reveal multiple independent evolution of diagnostic Biol. J. Linn. Soc., 74: 197-203. doi:10.1111/j.1095- morphological characters in the "Higher Oribatida" 8312.2001.tb01386.x (Acari), conflicting current classification schemes — BMC Evol. Biol., 10: 246. doi:10.1186/1471-2148-10- Proche¸sS., Marshall D.J. 2001 — Global distribution pat- 246 terns of non-halacarid marine intertidal mites: impli- cations for their origins in marine habitats — J. Bio- Schatz H. 1991 — Arrival and establishment of Acari on geogr., 28: 47-58. doi:10.1046/j.1365-2699.2001.00513.x oceanic islands — In: Dusbábek F., Bukva V. (Eds) Modern Acarology Prague: Academia Prague and Pugh P.J.A. 1995 — Air-breathing littoral mites of sub- SPB Academic Publishing, The Hague, Vol. 2. p. 613- Antarctic South Georgia — J. Zool., London, 236: 649- 618. 666. doi:10.1111/j.1469-7998.1995.tb02737.x Schatz H. 1998 — Oribatid mites of the Galápagos Islands- Pugh P.J.A. 1997 — Acarine colonization of Antarc- faunistics, ecology and speciation — Exp. Appl. Ac- tica and the islands of the Southern Ocean: the arol., 22: 373-409. doi:10.1023/A:1006097928124 role of zoohoria — Polar Rec., 33: 113-122. doi:10.1017/S0032247400014431 Schubart H. 1970 — Ameronothrus schusteri n. sp., eine neue Oribatidae von der Küste Jugoslawiens (Arach- Pugh P.J.A., King P.E. 1986 — Activity rhythms in lit- nida: Acari) — Senckenberg. Biol., 51: 425-432. toral Acari under laboratory conditions — J. Exp. Marine Biol. Ecol., 100: 37-45. doi:10.1016/0022- Schubart H. 1971 — Vergleichende Morphologie 0981(86)90154-1 und taxonomische Revision der Oribatidenfami- lie Ameronothridae (Arachnida: Acari) mit Be- Pugh P.J.A., MacAlister H.E. 1994 — Acari of the supralit- merkungen über jahreszeitliche Verschiebungen toral zone on sub-Antarctic South Georgia — Pedobi- des Geschlechterverhältnisses [PhD Thesis] — Kiel: ologia, 38: 552-565. Christian-Albrechts-Universität. pp. 78. Pugh P.J.A., Mercer R.D. 2001 — Littoral Acari of Marion Schubart H. 1975 — Morphologische Grundlagen für die Island: ecology and extreme wave action — Polar Biol., Klärung der Verwandtschaftsbeziehungen innerhalb 24: 239-243. doi:10.1007/s003000000203 der Milbenfamilie Ameronothridae (Acari, Oribatei) — Pugh P.J.A. 2003 — Have mites (Acarina:Arachnida) col- Zoologica, 123: 23-91. onized Antarctica and the islands of the Southern Schulte G. 1973 — Vertikalwanderungen küstenbe- Ocean via air currents? — Polar Record, 39: 239-244. wohnender Milben (Acari, Oribatei) — Neth. J. Sea Pugh P.J.A., King P.E., Fordy M.R. 1987a — A comparison Res., 7: 68-80. doi:10.1016/0077-7579(73)90033-1 of the structure and function of the cerotegument in Schulte G. 1975 — Holarktische Artareale der two new species of Cryptostigmata (Acarina) — J. Nat. Ameronothridae (Acari, Oribatei) — Veröff. Inst. Hist., 21: 603-616. doi:10.1080/00222938700770371 Meeresforsch. Bremerhaven, 15: 339-357. Pugh P.J.A., King P.E., Fordy M.R. 1987b — Ambulacral Schulte G. 1976a — Gezeitenrhythmische Nahrungsauf- structure in the terrestrial moiety of the intertidal nahme und Kotballenablage einer terrestrischen Milbe Acari, and its relationship with the lifestyle of the (Oribatei: Ameronothridae) im marinen Felslitoral — Acari — Acarologia, 28: 3-13. Marine Biol., 37: 265-277. doi:10.1007/BF00387612 Pugh P.J.A., King P.E., Fordy M.R. 1990 — Respiration in Schulte G. 1976b — Zur Nahrungsbiologie der ter- Fortuynia maculata Luxton (Fortuyniidae: Cryptostig- restrischen und marinen Milbenfamilie Ameronothri- mata: Acarina) with particular reference to the role of dae (Acari, Oribatei) — Pedobiologia, 16: 332-352. van der Hammen’s organ — J. Nat. Hist., 24: 1529- Schulte G., Schuster R., Schubart H. 1975 — Zur Verbre- 1547. doi:10.1080/00222939000770881 itung und Ökologie der Ameronothriden (Acari, Orib- Richters F. 1907 — Die Fauna der Moosrasen des Gauss- atei) in terrestrischen, limnischen und marinen Leben- berges und einiger südlicher Inseln — In: Drygalski E. sräumen — Veröff. Inst. Meeresforsch. Bremerhaven, (Ed). Deutsche Südpolar-Expedition 1901-1903. Berlin, 15: 359-385. Reimer Verlag. p. 259-302. Schulte G., Weigmann G. 1977 — The evolution of the Schaefer I., Norton R.A., Scheu S., Maraun M. 2010 family Ameronothridae (Acari: Oribatei) II. Ecological — Arthropod colonization of land – Linking aspects — Acarologia, 19: 167-173.

719 Pfingstl T.

Schuster R. 1957 — Haloribatula tenareae nov. gen., nov. (http://escalera.bio.ucm.es/usuarios/bba/cont/docs spec., eine neue Oribatide aus dem mediterranen Euli- /RO_1.pdf) toral (Acari) — Zool. Anz., 159: 121-127. Syamjith P.K., Ramani N. 2013 — Association of a man- Schuster R. 1963 — Thalassozetes riparius n. gen., grove dwelling euphthiracarid mite, Acrotritia clavata n. sp., eine litoralbewohnende Oribatide von be- (Märkel 1964) (Acari: Oribatida) with the epilithic merkenswerter morphologischer Variabilität (Acari- alga, Microspora sp. — Int. J. Acarol., 39: 615-619. Oribatei) — Zool. Anz., 171: 391-403. doi:10.1080/01647954.2013.862568 Schuster R. 1966 — Hornmilben (Oribatei) als Bewohner Thorell T. 1871 — Om Arachnider fran Spetsbergen och des marinen Litorals — Veröff. Inst. Meeresforsch. Beeren-Eiland — Öfvers. Kongl. Vet. Akad. Förh., 28: Bremerhaven, Sonderband II: 319-327. 683-702. Travé J. 1963 — Écologie et biologie des Oribates Schuster R. 1977 — Die Selenoribatidae, Eine Thalasso- (Acariens) saxicoles et arboricoles — Vie et Milieu, bionte Familie der Hornmilben — Acarologia, 19(1), suppl. 14: 1-286. 155–160. Travé J. 1986 — Les taenidies respiratoires des Oribates — Schuster R. 1979 — Soil mites in the marine environment Acarologia, 27: 85-94. — Recent Advances Acarol., 1: 593-602. Trouessart E.L. 1912 — The Acariens of the Scottish na- Schuster R. 1986 — Bodenbewohnende Milben (Acari) tional Antarctic Expedition — In: Bruce W.S. (Ed). Re- aus Niedersachsen und anderen Regionen Deutsch- port on the scientific results of the voyage of S.Y. "Sco- lands (BRD) — Braunschw. Naturkundl. Schriften, 3: tia" during the years 1902, 1903 and 1904. Edinburgh: 519-525. The Scottish Oceanographical Laboratory. p. 81-86. Schuster R. 1989 — Transoceanic distribution of air- Vitzthum H.G. 1942 — Acarina. In: Braun H.G. (Ed.). breathing littoral mites — Progr. Acarol., 1: 355-362. Klassen und Ordnungen des Tierreichs. Leipzig: Sitnikova L.G. 1975 — The family Ameronothridae Akademische Verlagsgesellschaft Becker and Erler Balogh, 1961 — In: Ghilyarov M.S. (Ed). Key to soil Kom. Ges. p. 1011. inhabiting mites. . Moscow: Nauka Wallwork J.A. 1962 — A redescription of Notaspis antarcti- Press. p. 232-234. cus Michael, 1903 (Acari: Oribatei) — Pac. Insects, 4: 869-880. Sømme L., Block W. 1984 — Ecophysiology of two inter- tidal mites at South Georgia — Oikos, 42: 276¬–282. Wallwork J.A. 1963 — The Oribatei (Acari) of Macquarie Island — Pac. Insects, 5: 721-769. Søvik G. 2003 — Observations on ovoviviparity Wallwork J.A. 1964 — A revision of the family Podacari- and mixed-parity mode in arctic populations of dae Grandj. (Acari: Oribatei) — Acarologia, 6: 387- Ameronothrus lineatus (Acari, Oribatida) — Acarologia, 399. 43: 393-398. Wallwork J.A. 1966 — More Oribatid mites (Acari: Cryp- Søvik G. 2004 — The biology and life history of arctic tostigmata) from Campbell I. — Pac. Insects, 8: 849- populations of the littoral mite Ameronothrus lineatus 877. (Acari, Oribatida) — Exp. Appl. Acarol., 34: 3-20. Wallwork J.A. 1967 — Cryptostigmata (Oribatid doi:10.1023/B:APPA.0000044436.80588.96 mites) — Entomol. Antarct., 10: 105-122. Søvik G., Leinaas H.P., Ims R.A., Solhøy T. 2003 — Popu- doi:10.1029/ar010p0105 lation dynamics and life history of the oribatid mite Wallwork J.A. 1970 — Acarina: Cryptostigmata of South Ameronothrus lineatus (Acari, Oribatida) on the high Georgia — Pac. Insects Monogr., 23: 161-178. arctic archipelago of Svalbard — Pedobiologia, 47: 257- Wallwork J.A. 1981 — A new aquatic oribatid mite 271. from western Australia (Acari: Cryptostigmata: Strenzke K. 1961 — Selenoribates foveiventris n. gen., n. Ameronothridae) — Acarologia, 22: 333-339. sp., aus der unterirdischen Feuchtzone der Küste des Walter D.E., Lindquist E.E., Smith I.M. 2009 — Order Roten Meeres (Acarina: Oribatei) — Kieler Meeres- Trombidiformes — In: Krantz G.W., Walter D.E. (Eds) forsch., 17: 89-93. A manual of Acarology – Third edition. Texas: Texas Strong J. 1967 — Ecology of terrestrial arthropods at Tech University Press. p. 430-564. Palmer Station, Antarctic Peninsula — Antarct. Res. Weigmann G. 1975a — Labor- und Freilanduntersuchun- Ser. Washington, 10: 357-371. gen zur Generationsdauer von Oribatiden (Acari: Ori- Subías L.S. 2004 — Listado sistemático, sinonímico batei) — Pedobiologia, 15: 133-148. y biogeográphico de los ácaros oribátidos (Acar- Weigmann G. 1975b — Vorkommen von Ameronothrus iformes: Oribatida) del mundo — Graellsia, 60: (Acari, Oribatei) im Litoral Südafrikas — Veröff. Inst. 3-305. Internet update 2016, available from: Meeresforsch. Bremerhaven, 15: 65-67.

720 Acarologia 57(3): 693–721 (2017)

Weigmann G., Schulte G. 1975 — Ameronothrus schubarti Worland M.R., Convey P. 2001 — Rapid cold hardening in n.sp. aus dem marinen Litoral Kaliforniens — Senck- Antarctic microarthropods — Funct. Ecol., 15: 515-524. enberg. Biol., 56: 133-143. doi:10.1046/j.0269-8463.2001.00547.x Weigmann G., Schulte G. 1977 — The evolution of the Worland M.R., Lukešová A. 2000 — The effect of feed- family Ameronothridae (Acari: Oribatei) I. Morpho- ing on specific soil algae on the cold-hardiness of two logical aspects — Acarologia, 19: 161-166. Antarctic micro-arthropods (Alaskozetes antarcticus and Willmann C. 1931 — Moosmilben oder Oribatiden (Cryp- Cryptopygus antarcticus) — Polar Biol., 23: 766-774. tostigmata) — In: Dahl F. (Ed). Die Tierwelt Deutsch- doi:10.1007/s003000000150 lands. Band 22. Jena: Fischer Jena. p. 79-200. Willmann C. 1936 — Oribatiden von Bonaire und Curaçao — Zool. Jb. Syst., 67: 429-441. COPYRIGHT Woas S. 2002 — Acari: Oribatida — In: Adis J. (Ed). Ama- zonian Arachnida and Myriapoda. Sofia-Moscow: Pfingstl T. Acarologia is under free license. Pensoft Publishers. p. 21-291. This open-access article is distributed under the terms of Woodring J.P. 1973 — Comparative morphology, the Creative Commons-BY-NC-ND which permits unre- functions and homologies of the coxal glands stricted non-commercial use, distribution, and reproduc- in oribatid mites — J. Morph., 139: 407-430. tion in any medium, provided the original author and doi:10.1002/jmor.1051390404 source are credited.

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