Chapter 5-4: Tardigrades: Species Relationships - Bryophyte Ecology

CHAPTER 5-4 

TARDIGRADES: SPECIES 

RELATIONSHIPS 

Figure 1. Hypsibius dujardini, a species that is common on bryophytes. Photo by Łukasz Kaczmarek and Łukasz Michalczyk. 

Species Relationships 

Since bryophytes vary widely in structure, 

compactness, and moisture-holding nature, one would 

expect that some bryophytes would be more suitable for 

tardigrades than others, causing specificity. But is that 

really the case? 

Although Hofmann and Eichelberg (1987), in Lahnau 

near Giessen, Germany, found a correlation between 

species of tardigrade and degree of moisture in their 

preferred mosses, there seemed to be no example of a 

single species of tardigrade preferring a single species of 

moss. It appeared that species of bryophyte was not an 

important factor for most tardigrades. 

A number of studies include the names of the 

bryophytes where the tardigrades have been found, but 

quantitative approaches are limited. For example, Degma 

(2006) found Echiniscus reticulatus on the moss Ctenidium 

molluscum (Figure 2) and Testechiniscus spitsbergensis 

from the mosses Tortella tortuosa (Figure 3), Ctenidium 

molluscum, Distichium capillaceum (Figure 4), and 

Ditrichum flexicaule (Figure 5) in Slovakia. 

Baxter (1979) did find differences in the tardigrades on 

several moss species in Ireland. These represented 

different growth forms as well as habitats. Some of their 

more specific finds include stream bank mosses that had 

Diphascon oculatum. Polytrichum (Figure 6), with its 

more open structure, had Diphascon scoticum (Figure 7). 

Hypsibius dujardini (Figure 1) was abundant, accompanied 

by Isohypsibius tuberculatus, on the turfs of 

Rhytidiadelphus squarrosus (Figure 8). 

Figure 2. Ctenidium molluscum, a moss that is home to 

Echiniscus reticulatus, among others. Photo by Michael Lüth. 

45

46 Chapter 5-4: Tardigrades: Species Relationships 

Figure 3. Tortella tortuosa, a Slovakian habitat for 

Testechiniscus spitsbergensis. Photo by Michael Lüth. 

Figure 4. Distichium capillaceum, a known tardigrade 

habitat. Photo by Michael Lüth. 

Figure 5. Ditrichum flexicaule, a habitat for Testechiniscus 

spitsbergensis. Photos by Michael Lüth. 

Figure 6. Polytrichum, a moss with spreading leaves that 

provide limited tardigrade habitat. Photo by Michael Lüth. 

Figure 7. Diphascon scoticum, a tardigrade that is able to 

inhabit Polytrichum. Photo by Paul Bartels. 

Figure 8. Rhytidiadelphus squarrosus, where Baxter (1979) 

found Isohypsibius tuberculatus and Diphascon scoticum. Photo 

by Michael Lüth. 

Horning et al. (1978) examined the tardigrades on 21 

species of mosses in New Zealand and listed the tardigrade 

species on each (Table 1). Some moss species clearly had 

more tardigrade species than others, ranging from 1 on 

Syntrichia rubra to 17 on Hypnum cupressiforme (Figure 

9). Limbophyllum divulsulum had 16 species.

Chapter 5-4: Tardigrades: Species Relationships 47 

Table 

1. Tardigrade species found on the most common moss taxa in New Zealand. From Horning et al. 1978. 

Breutelia elongata Macrobiotus hibiscus 

Macrobiotus liviae 

Milnesium tardigradum 

Minibiotus intermedius 

Breutelia pendula Diphascon prorsirostre 

Diphascon scoticum 

Doryphoribius zyxiglobus 

Hypechiniscus exarmatus 

Macrobiotus hibiscus 



Bryum campylothecium Hypsibius convergens 

Isohypsibius sattleri 


Bryum dichotomum Hypsibius wilsoni 

Macrobiotus coronatus 


Bryum truncorum Diphascon chilenense 



Isohypsibius wilsoni 


Macrobiotus furciger 


Macrobiotus recens 

Paramacrobiotus areolatus 

Paramacrobiotus richtersi 

Ramazzottius oberhaeuseri 

Dicranoloma billardieri Hypechiniscus exarmatus 


Dicranoloma grossialare Diphascon prorsirostre 


Hypsibius dujardini 

Isohypsibius cameruni 


Limmenius porcellus 

Macrobiotus anderssoni 




Pseudechiniscus novaezeelandiae 

Dicranoloma menziesii Macrobiotus hibiscus 



Dicranoloma robustum Echiniscus bigranulatus 





Pseudechiniscus suillus 

Dicranoloma trichopodum Echiniscus quadrispinosus 

Echiniscus q. brachyspinosus 


Pseudechiniscus lateromamillatus 

Hypnum cupressiforme Diphascon alpinum 

Diphascon bullatum 

Echiniscus quadrispinosus 

Echiniscus spiniger 









Oreella mollis 





Lembophyllum divulsum Diphascon alpinum 


Hypsibius convergens 








Macrobiotus subjulietae 






Macromitrium erosulum Macrobiotus furciger 




Macromitrium longipes Doryphoribius zyxiglobus 




Porotrichum ramulosum Diphascon alpinum 



Echiniscus bigranulatus 







Macrobiotus rawsoni 

Minibiotus aculeatus 

Pseudechiniscus lateromamillatus 



Racomitrium crispulum Calohypsibius ornatus 

Diphascon alpinum 

Echiniscus quadrispinosus 

Echiniscus zetotrymus 

Hebesuncus conjungens 







Macrobiotus orcadensis 


Oreella minor 



Racomitrium lanuginosum Diphascon scoticum 

Echiniscus quadrispinosus brachyspinosus 

Echiniscus vinculus 







Racomitrium ptychophyllum Echiniscus quadrispinosus 

Echiniscus velaminis 








Syntrichia princeps Hypsibius convergens 







Syntrichia rubra Diphascon scoticum 

Tortula subulata var. serrulata Diphascon scoticum 

Paramacrobiotus areolatus


Figure 9. Hypnum cupressiforme, the moss with the most tardigrade species in the New Zealand study by Horning et al. (1978), 

shown here on rock and as a pendant epiphyte. Photos by Michael Lüth. 

Hopefully lists like the one provided by Horning et al. 

(1978) will eventually permit us to determine the 

characteristics that foster tardigrade diversity and 

abundance. Perhaps the moss Hypnum cupressiforme had 

the most tardigrade species among the mosses in New 

Zealand because of its own wide habitat range there. 

However, Degma et al. (2005) found that distribution of the 

number of tardigrade species on this moss in their Slovakia 

sites was random, as supported by a Chi-square goodness 

of fit test. Nevertheless, its ubiquitous nature on a wide 

range of habitats in New Zealand may account for the 

greater number of species of tardigrades on Hypnum 

cupressiforme in the New Zealand study. 

A different kind of vertical zonation occurs among 

tardigrades on trees. In the Great Smoky Mountains 

National Park, the number of tardigrade species among 

epiphytes at breast height was greater than the number of 

species found at the base (Bartels & Nelson 2006). 

In a study of 270 Chinese mosses in the Herbarium of 

the Missouri Botanical Garden, only 78 specimens, 

representing 10 locations, had tardigrades (Beasley & 

Miller 2007). These were represented by 12 species. 

Several additional species were found and may be new 

species, but more specimens are needed to make adequate 

determinations. In this study, the mosses were identified 

and I present the moss and fauna here to facilitate 

comparisons for persons looking for possible specificity in 

conjunction with other studies (Table 2). 

In their study of Chinese mosses Beasley and Miller 

(2007) found that Heterotardigrada (armored tardigrades) 

were better represented than were Eutardigrada 

(unarmored tardigrades), a factor the authors attribute to the 

xerophilic moss samples and the locality, which has hot, 

dry summers, very cold, dry winters, low summer rainfall, 

and high winds (Fullard 1968). The Heterotardigrada have 

armor, which may account for their ability to withstand the 

dry habitat. These tardigrades also have cephalic (head) 

appendages with a sensorial function, a character lacking in 

the Eutardigrada, but so far their function has not been 

related to a bryophyte habitat. Beasley and Miller (2007) 

found little specificity, but most of the mosses they 

examined were xerophytic and exhibited similar moisture 

requirements. They did find that Echiniscus testudo (see 

Figure 11) occurred on a wider variety of mosses than did 

other tardigrade species. 

Table 2. Distribution of tardigrades on specific mosses in 

Xinjiang Uygur Region, China, based on herbarium specimens. 

From Beasley & Miller 2007. 

tardigrade numb/samples moss 

Bryodelphax asiaticus 1/1 Pseudoleskeella catenulata 

Cornechiniscus holmeni 18/5 Grimmia tergestina 

Mnium laevinerve 

Schistidium sp. 

Echiniscus blumi 4/4 Abietinella abietina 


Echiniscus canadensis 82/7 Grimmia laevigata 

Grimmia ovalis 

Grimmia tergestina 

Echiniscus granulatus 8/3 Grimmia longirostris 

Schistidium trichodon 


Echiniscus testudo 11/4 Grimmia anodon 

Grimmia longirostris 


Lescuraea incurvata 

Pseudoleskeella catenulata 


Echiniscus trisetosus 33/5 Abietinella abietina 


Pseudoleskeella catenulata 

Macrobiotus mauccii 2/2 Schistidium sp. 

Milnesium asiaticum 10/4 Grimmia anodon 




Milnesium longiungue 4/2 Grimmia laevigata 


Milnesium tardigradum 5/4 Grimmia tergestina 


Orthotrichum sp. 

Paramacrobiotus alekseevi 5/4 Brachythecium albicans 


Figure 10. Macrobiotus hufelandi. Photo by Martin Mach.

Figure 11. Adult Echiniscus. Photo by Martin Mach. 

Kathman and Cross (1991) found that species of 

bryophyte had no influence on the distribution or 

abundance of tardigrades from five mountains on 

Vancouver Island, British Columbia, Canada. Despite a 

lack of specificity among the tardigrades, 39 species 

inhabited these 37 species of mountain bryophytes, 

comprising 14,000 individuals. Several researchers 

contend that any terrestrial species of tardigrade can be 

found on any species of moss, given the "appropriate 

microhabitat conditions" (Bertrand 1975; Ramazzotti & 

Maucci 1983). If these tardigrade bryophyte specialists 

find no differences among the bryophytes, can we blame 

the ecologists for lumping all the bryophytes in their 

studies as well? 

On Roan Mountain in Tennessee and North Carolina, 

Nelson (1973, 1975) found no specificity among 21 

tardigrade species on 25 bryophyte species. Hunter (1977) 

in Montgomery County, Tennessee, and Romano et al. 

(2001) in Choccolocco Creek in Alabama, USA, again 

were unable to find any dependence of tardigrades upon a 

particular species of bryophyte in their collections. In fact, 

Kathman and Cross (1991) were unable to find any 

correlation with altitude or aspect throughout a span from 

150 to 1525 m. They concluded that it was the presence of 

bryophyte that determined tardigrade presence, not the 

species of bryophyte, altitude, or locality. 

In collections from Giessen, Germany, the most 

common tardigrade species, the cosmopolitan Macrobiotus 

hufelandi, (Figure 10) had no preference for any moss 

species (Hofmann 1987). But lack of influence of 

bryophyte species may not always be the case. Hofmann 

(1987) used a preference index to show that four out of 

sixteen tardigrades from Giessen had distinct preferences 

among five moss species and that they seemed to prefer 

cushion mosses over sheet mosses. Also contrasting with 

the above researchers, Bertolani (1983) found that there 

seemed to be a species relationship between tardigrades 


and coastal dune mosses. It is possible that this is again 

related to moisture. The moisture relationship might also 

explain why mosses on rotten logs seem to have few 

tardigrades. Could it be that they are too wet for too long? 

Growth Forms 

There is some indication that species differences may 

exist, based on growth form. The bryophyte form can 

affect the moisture-holding capacity and rate of loss of 

moisture. The foregoing evidence suggests that the 

moisture-holding capacity of cushion mosses was probably 

a desirable trait in that habitat. On the other hand, Beasley 

(1990) found that more samples of clubmosses 

(Lycopodiaceae) (75%) had tardigrades than did mosses 

(46%) or liverworts (0%) in Gunnison County, Colorado. 

Jönsson (2003) compared the tardigrade fauna on 

mosses in a coniferous forest and those on mosses in an 

adjacent clearcut area in Southern Sweden. He found 

sixteen tardigrade species, with the cosmopolitan 

Macrobiotus hufelandi (Figure 10) being by far the most 

common. Wefts had more tardigrades than other mosses. 

The forest samples tended to have more species, as one 

might expect based on moisture relations. 

Kathman and Cross (1991) found that tardigrades from 

Vancouver Island were more common on weft-forming 

mosses than on turfs, suggesting that the thick carpets of 

the wefts were more favorable habitat than the thinly 

clustered turfs with their thick rhizoidal mats and attached 

soil. Contrasting with some of these findings, and the 

preference for cushion mosses in the study by Hofmann 

(1987), Diane Nelson (East Tennessee State University, 

Johnson City, pers. comm. in Kathman & Cross 1991) 

found no preference for sheet or cushion mosses in her 

Roan Mountain, Virginia, USA study. Rather, those 

tardigrades were more common in thin, scraggly mosses or 

in small tufts than in thick cushion mosses. 

Sayre and Brunson (1971) compared tardigrade fauna 

on mosses in 26 North American collections from a variety 

of habitats and substrata (Figure 12). They found that 

mosses of short stature in the Thuidiaceae (Figure 13) and 

Hypnaceae (Figure 14) had the highest frequencies of 

tardigrades. Other moss-dwellers were found in fewer 

numbers on members of the moss families Orthotrichaceae 

(epiphytic and rock-dwelling tufts; Figure 15), 

Leucobryaceae (cushions; Figure 16), Polytrichaceae (tall 

turfs; Figure 17), Plagiotheciaceae (low mats; Figure 18), 

and Mniaceae (mats & wefts; Figure 19). 

Collins and Bateman (2001), studying tardigrade fauna 

of bryophytes in Newfoundland, Canada, found that rate of 

desiccation of the mosses affected distribution of 

tardigrades, and this suggests that bryophyte species and 

growth forms that dehydrate quickly should have fewer 

individuals and probably different or fewer species than 

those that retain water longer (see Chapter 4-6). In 

different climate regimes, that rate will differ. This may 

explain a preference for cushions in some locations and not 

in others. Data are needed on humidity within the various 

growth forms of bryophytes, correlated with tardigrade 

densities, to try to explain why different growth forms 

seem to be preferred in different locations.


Figure 12. Relative frequency of tardigrades on bryophytes 

of various North American substrata. Redrawn from Sayre & 

Brunson 1971. 

Figure 13. Thuidium delicatulum (Thuidiaceae), a lowstature 

moss that is a good tardigrade habitat. Photo by Michael 

Lüth. 

Figure 14. Hypnum revolutum (Hypnaceae), representing a 

family that includes low-stature mosses that had among the 

highest frequencies of tardigrades in 26 North American 

collections (Sayre & Brunson 1971). Photo by Michael Lüth. 

Figure 15. Orthotrichum pulchellum, an epiphytic moss in 

the Orthotrichaceae. This family is among those with lower 

numbers of tardigrades in the North American study of Sayre & 

Brunson (1971) compared to families of mat-forming species. 

Photo by Michael Lüth. 

Figure 16. Leucobryum glaucum, a cushion moss in the 

Leucobryaceae. This family of mosses had lower numbers of 

tardigrades than those found in the mat-forming mosses in 26 

North American collections (Sayre & Brunson 1971). Photo by 

Michael Lüth. 

Figure 17. Polytrichum juniperinum, a moss in the 

Polytrichaceae. This family of mosses tends to have low numbers 

of tardigrades (Sayre & Brunson 1971). The tardigrades often 

nestle in the leaf bases where water evaporates more slowly. 

Photo by Michael Lüth.

Figure 18. Plagiothecium denticulatum, a low-growing soil 

moss in Plagiotheciaceae, a family with limited numbers of 

tardigrade dwellers (Sayre & Brunson 1971). The flattened 

growth habit provides few protective chambers, perhaps 

accounting for the lower numbers. Photo by Michael Lüth. 

Figure 19. Plagiomnium cuspidatum, a soil moss in the 

Mniaceae, a family with limited numbers of tardigrade dwellers 

(Sayre & Brunson 1971). The spreading nature of the vertical 

shoots and the flattened nature of the horizontal shoots would 

most likely not provide many protective chambers for the 

tardigrades. Photo by Michael Lüth. 

Liverworts 

I would expect liverworts, with their flat structure, to 

have at least some differences. But there seems to be a 

paucity of reports on liverworts. Hinton and Meyer (2009) 

found two species of tardigrades [Milnesium tardigradum 

(Figure 20) and Macrobiotus hibiscus], both also common 

among mosses, in samples of the liverwort Jungermannia 

sp.) (Figure 21). 

Liverworts may actually house some interesting 

differences as a result of their underleaves (Figure 22) and 

flattened growth form (Figure 23). In their New Zealand 

study, Horning et al. (1978) found that among the 

liverworts (Table 3), Porella elegantula (Figure 22) had the 

most species (16). The folds and underleaves of this genus 

form tiny capillary areas where water is held, perhaps 

accounting for the large number of species. Interestingly, 

the tardigrade Macrobiotus snaresensis occurred on several 


liverwort species (4 Lophocolea species, Plagiochila 

deltoidea), but did not appear in any moss collections. Of 

150 liverwort samples (26 species), 27% had tardigrades, 

with a total of 16 species, mean of 2.8 species, range 1-9. 

In 107 samples of foliose lichens, 60.7% had tardigrades, 

mean 2.2 species, range 1-11. 

Figure 20. Milnesium tardigradum, an inhabitant of both 

mosses and liverworts. Photo by Björn Sohlenius, Swedish 

Museum of Natural History. 

Figure 21. The leafy liverwort Jungermannia sphaerocarpa, 

representing a genus from which tardigrades are known. Photo by 

Michael Lüth. 

Figure 22. Porella elegantula, showing the underleaves and 

folds that create numerous capillary spaces. Photo by Jan-Peter 

Frahm.


Table 3. Species of tardigrades found on 13 liverwort species in New Zealand and surrounding islands. From Horning et al. 1978. 

Liverwort Species Tardigrade Species Liverwort Species Tardigrade Species 

Lophocolea innovata Macrobiotus snaresensis 

Lophocolea. minor Macrobiotus snaresensis 

Lophocolea. subporosa Macrobiotus snaresensis 

Lophocolea semiteres Diphascon chilenense 


Lophocolea subporosa: Diphascon scoticum 


Macrobiotus snaresensis 

Lophocolea sp. Macrobiotus liviae 

Metzgeria decipiens Echiniscus spiniger 


Paramacrobiotus areolatus) 








Metzgeria decrescens Diphascon scoticum 




Plagiochila deltoidea Echiniscus bigranulatus 



Isohypsibius cameruni 

Figure 23. Underside of leafy liverwort with two 

tardigrades. Photo by Łukasz Kaczmarek and Łukasz 

Michalczyk. 

It appears that at least some researchers have paid 

attention to liverworts. Christenberry (1979) found 

Echiniscus kofordi and E. cavagnaroi on liverworts in 

Alabama, USA. Hinton and Meyer (2009) found 

Milnesium tardigradum (Figure 20) and Macrobiotus 

hibiscus in a liverwort sample from Georgia, USA. 

Michalczyk and Kaczmarek (2006) found a new species, 

Paramacrobiotus magdalenae (see Figure 24), on 





Plagiochila fasciculata Diphascon scoticum 


Plagiochila obscura Macrobiotus coronatus 



Plagiochila strombifolia Macrobiotus anderssoni 


Porella elegantula Doryphoribius zyxiglobus 

Echiniscus vinculus 

Diphascon alpinum 

Diphascon bullatum 

Diphascon prorsirostre 








Minibiotus aculeatus 




liverworts in Costa Rica. Newsham et al. (2006) identified 

the leafy liverwort Cephaloziella varians and used it to 

experiment on the effects of low temperature storage on 

tardigrades and other Antarctic invertebrates. 

Just what do we mean by "appropriate habitat 

conditions"? The bryophytes only occur in conditions that 

are appropriate for them, hence defining the conditions for 

the tardigrades. And the bryophytes create habitat 

conditions of moisture due to their morphology and 

substrate preference. Lack of species preference in many 

studies may result from methods that were insensitive to 

subtle differences or that failed to control for microhabitat 

differences. Usually no statistical tests were employed, 

sample sizes were small, and enumeration was often simple 

presence/absence data. 

Figure 24. Paramacrobiotus areolatus. Photo by Martin 

Mach.

Substrate Comparisons 

Meyer (2006) extended the comparison of substrata in 

Florida, USA, to include not only liverworts, mosses, and 

foliose lichens, but also ferns. They found 20 species of 

tardigrades on 47 species of plants and lichens. They found 

that some species were positively associated with mosses 

or with foliose lichens, but as in most other studies, there 

was no association with any particular plant or lichen 

species. 

Guil et al. (2009a) reviewed tardigrades and their 

habitats (altitude, habitat characteristics, local habitat 

structure or dominant leaf litter type, and two bioclimatic 

classifications), including bryophytes and leaf litter at 

various elevations. They were able to show some habitat 

preference. Species richness was most sensitive to 

bioclimatic classifications of macroenvironmental gradients 

(soil and climate), vegetation structure, and leaf litter type. 

A slight altitude effect was discernible. These relationships 

suggest that differences among bryophyte species should 

exist where bryophyte species occupy different 

environmental types or maintain different 

microenvironments within a habitat. But it also suggests 

that within the same habitat, bryophytes of various growth 

forms should provide different moisture regimes, hence 

creating species relationship differences. 

In a different study in the Iberian Peninsula, Guil et al. 

(2009b) found that leaf litter habitats showed high species 

richness and low abundances compared to rock habitats 

(mosses and lichens), which had intermediate species 

richness and high abundances. Tree trunk habitats (mosses 

and lichens) showed low numbers of both richness and 

abundances. One might conclude that the moisture of these 

habitats is the overall determining factor, and this should 

coincide with bryophyte species groups on the large scale. 

Miller et al. (1996) found six species of tardigrades in 

lichen and bryophyte samples on ice-free areas at Windmill 

Islands, East Antarctica. The tardigrade species Diphascon 

chilenense (see Figure 25), Hypsibius antarcticus (see 

Figure 26), and Pseudechiniscus suillus showed a positive 

association with bryophytes and a negative association with 

algae and lichens. 

Figure 25. Diphascon sp., member of one of the most 

common bryophyte-dwelling genera. Photo by Martin Mach. 

Meyer and Hinton (2007) reviewed the Nearctic 

tardigrades (Greenland, Canada, Alaska, continental USA, 

northern Mexico). They found that one-third of the species 

occur in both cryptogams (lichens and bryophytes) and 


soil/leaf litter (Table 4). Few tardigrades occurred 

exclusively in soil/leaf litter habitats. Although many 

occurred among both bryophytes and lichens, 18 species 

occurred only in bryophytes. 

Figure 26. Hypsibius. Photo by Yuuji Tsukii. 

Table 4. Comparison of tardigrades inhabiting their primary 

substrates in the Nearctic realm. Only species present on that 

substrate in at least three sites are included. From Meyer & 

Hinton 2007. 

Substrate category number of species 

Cryptogams only 64 

Both cryptogams and soil/leaf litter 27 

Soil/leaf litter only 3 

Both bryophyte and lichen 50 

Bryophyte only 18 

Lichen only 5 

Beasley (1990) conducted a similar study in Colorado, 

USA. Out of 135 samples of liverworts, mosses, lichens, 

and club mosses (Lycopodiaceae), they found 20 species on 

55 samples. There were no tardigrades on the liverworts, 

but they were on 46% of mosses and 43% of lichens. The 

big surprise is that 75% of the clubmosses had tardigrades. 

In the Great Smoky Mountains National Park, Bartels 

and Nelson (2006) found that the number of species 

differed little among the substrates they sampled (soil, 

lichen, moss, & stream habitats). Whereas it is not unusual 

for the soil, lichens, and mosses to have similar fauna and 

richness, it seems a bit unusual for the stream habitat to be 

as rich. 

Horning et al. (1978) collected from soil, fungi, algae, 

bryophytes, lichens, marine substrata, freshwater substrata, 

and litter in New Zealand and surrounding islands. From 

bryophyte and lichen habitats, they found that all 14 of the 

most abundant species occurred in at least three of the five 

"plant" categories (three lichen forms, liverworts, and 

mosses). Among these, the highest occurrence was among 

mosses. Although Milnesium tardigradum (Figure 20) was 

slightly more abundant on lichens than on mosses, the 

combined numbers on mosses and liverworts was still 

higher. Horning et al. identified the bryophytes and lichens 

and presented the species of tardigrades on each (Table 1, 

Table 3, Table 5). In 559 moss samples, 45.8% had 

tardigrades, mean of 1.8 species, range 1-8 (Table 1). Of 

55 species of tardigrades known for New Zealand, 45 

occurred on mosses.


Table 5. Comparison of numbers of individuals and percentage of individuals of 14 tardigrade species on liverworts, mosses, and 

lichens in collections from New Zealand and surrounding islands. From Horning et al. 1978. 

n liverworts % mosses % lichens % 

(150) (559) (239) 

Pseudechiniscus novaezeelandiae 46 8.70 56.50 23.90 

Pseudechiniscus suillus 43 6.98 44.19 27.91 

Macrobiotus harmsworthi 89 5.62 55.06 34.83 

Macrobiotus hibiscus 90 7.78 60.00 17.78 

Minibiotus intermedius 65 7.69 41.54 32.30 

Milnesium tardigradum 143 7.69 35.66 37.06 

Hypsibius dujardini 32 10.53 50.00 2.63 

Paramacrobiotus areolatus (Figure 27) 58 3.45 60.34 18.97 

Echiniscus bigranulatus 18 5.56 38.89 38.89 

Hypechiniscus gladiator 21 19.05 61.90 9.50 

Diphascon scoticum 35 11.43 65.71 11.43 

Macrobiotus liviae 72 8.33 56.94 18.06 

Macrobiotus anderssoni 63 11.11 42.86 22.22 

Macrobiotus furciger 89 12.36 50.56 22.47 

Figure 27. Paramacrobiotus areolatus, a tardigrade that 

inhabits both mosses and liverworts. Photo by Björn Sohlenius at 

the Swedish Museum of Natural History. 

Finding New Species 

The common appearance of tardigrades among 

bryophytes causes those who seek to describe new taxa to 

go first to the mossy habitats. In this spirit, Kaczmarek and 

Michalczyk (2004a) found the new species of mossdwelling 

Doryphoribius quadrituberculatus in Costa Rica. 

From mosses in China they described the new species 

Bryodelphax brevidentatus (Kaczmarek et al. 2005) and B. 

asiaticus (Kaczmarek & Michalczyk 2004b), as did Li and 

coworkers for Echiniscus taibaiensis (Wang & Li 2005), 

Isohypsibius taibaiensis (Li & Wang 2005), Isohypsibius 

qinlingensis (Li et al. 2005a), Pseudechiniscus papillosus 

(Li et al. 2005b), Pseudechiniscus beasleyi, Echiniscus 

nelsonae, and E. shaanxiensis (Li et al. 2007), and 

Tumanov (2005) for Macrobiotus barabanovi and M. 

kirghizicus. Pilato and Bertolani (2005) described 

Diphascon dolomiticum from Italy. 

New species from South Africa are no surprise, as 

enumeration of small organisms in that country is barely 

out of its infancy. Kaczmarek and Michalczyk (2004c) 

described the new species Diphascon zaniewi in the 

Dragon Mountains there. Other species found there were 

more cosmopolitan: Hypsibius maculatus (previously 

known only from Cameroon and England), H. convergens 

(Figure 28), Paramacrobiotus cf. richtersi, and Minibiotus 

intermedius (Figure 29). But the South African tardigrade 

fauna still remains largely unknown. 

Figure 28. Hypsibius convergens, a moss-dweller. Photo by 

Björn Sohlenius, Swedish Museum of Natural History. 

Figure 29. Minibiotus intermedius mouth. Photo by Łukasz 

Kaczmarek and Łukasz Michalczyk. 

Likewise, in South America, Michalczyk and 

Kaczmarek (2005) described Calohypsibius maliki as a new 

species from Chile; Michalczyk and Kaczmarek (2006) 

described Echiniscus madonnae (Figure 30) from Peru, all 

from bryophytes. In Argentina they described Macrobiotus 

szeptyckii and Macrobiotus kazmierskii (Kaczmarek &

Michalczyk 2009). In 2008 Degma et al. described another 

new species (Paramacrobiotus derkai) from Chile, a 

country where only 29 species had previously been 

described. 

Figure 30. Echiniscus madonnae, a moss dweller from Peru. 

Photo by Łukasz Kaczmarek & Łukasz Michalczyk. 

In Portugal, lichens and mosses provided the new 

species Minibiotus xavieri to Fontoura and coworkers 

(2009). In Cyprus, Kaczmarek and Michalczyk (2004d) 

described Macrobiotus marlenae (Figure 31). Macrobiotus 

kovalevi proved to be a new species from mosses in New 

Zealand (Tumanov 2004). Clearly, mosses have been a 

favorite sampling substrate for tardigrade seekers 

(Kaczmarek & Michalczyk 2009) and most likely hold 

many more undescribed species around the world. 

Figure 31. Macrobiotus marlenae. Photo by Łukasz 

Kaczmarek and Łukasz Michalczyk. 

Summary 

Most studies indicate no correlation between 

bryophyte species and tardigrade species. There is 

limited indication that cushions may have more, but in 

other studies thin mats have more than cushions. Other 

studies indicate they are more common on weft-forming 

mosses than on turfs. Open mosses like Polytrichum 

seem to be less suitable as homes. There may be some 

specificity for liverworts rather than mosses, as for 

example Macrobiotus snaresensis in New Zealand. 

Unfortunately, many researchers have not identified the 

bryophyte taxa in tardigrade faunistic studies. A 

common garden study including several bryophyte 

species and tardigrades of the same or different species 

could be revealing. 


Acknowledgments 

Roberto Bertolani provided an invaluable update to the 

tardigrade taxonomic names and offered several 

suggestions on the text to provide clarification or correct 

errors. Łukasz Kaczmarek has provided me with 

references, images, contact information, and a critical read 

of an earlier version of the text. Martin Mach and Yuuji 

Tsukii have given permission to use images that illustrate 

the species. Michael Lüth has given permission to use his 

many bryophyte images, and my appreciation goes to all 

those who have contributed their images to Wikimedia 

Commons for all to use. Thank you to my sister, Eileen 

Dumire, for providing the view of a novice on the 

readability of the text. Tardigrade nomenclature is based 

on Degma et al. 2010. 

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Chapter 5-4: Tardigrades: Species Relationships - Bryophyte Ecology

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