The Ecological Distribution of Tardigrades in Newfoundland

0044-5231/01/240/03–04-291 $ 15.00/0

The Ecological Distribution of Tardigrades in Newfoundland*

Michael COLLINS1 and Lois BATEMAN2

1 Biology Department, Memorial University of Newfoundland, St. John’s, Newfoundland, Canada2 Science Division, Sir Wilfred Grenfell College, Memorial University of Newfoundland, Corner Brook,Newfoundland, Canada

Abstract. The ecological distribution of tardigrades on the island of Newfoundland, Canada is greatly affected byboth abiotic and biotic factors. Altitude and type of bedrock are major determining factors in tardigrade distribu-tion while both moisture content of the environment and rate of dessication of the mosses and lichens in whichthey live appear to be other factors contributing to their distribution. A number of cases of apparent competitiveexclusion and inter-specific competition have been noted which probably also affect tardigrade distribution.

Key words. Ecological distribution, habitat preference, tardigrades.

1. INTRODUCTION

A previous paper (BATEMAN & COLLINS 2001) provid-ed an overview of the thirty-one species of tardigradesso far located in terrestrial moss and lichen samplesfrom the various types of ecosystems occurring on theisland of Newfoundland and also included a compari-son of the species found in Newfoundland with speciesfound elsewhere in Canada and in other northernregions. This paper examines the ecological distribu-tion of these thirty-one species on the island. A numberof authors have attempted to classify terrestrial moss-living tardigrades according to the water content of themosses they inhabit and susceptibility to dessication.RAMAZZOTTI & MAUCCI (1983), and KINCHIN (1994),for instance, have classified species as xerophilic –typical of dry mosses; hygrophilic – characteristic ofmoist mosses; hydrophilic – found in wet mosses andin water; and eurytopic – found in all types of mosses.WRIGHT (1991) has classified British terrestrial tardi-grades into these same categories according to fourxeric variables used to assess susceptibility to dessica-tion, namely exposure to insolation, elevation, stan-dardized dessication rate, and hydration capacity ofthe habitat plant. BEASLEY (1978, 1988) has classified

tardigrades in both Oklahoma and in New Mexico intothese four groups as has CASKEY (1971) in Texas.A preliminary classification of Newfoundland tardi-grades has revealed that only in the case of Hypsibiusdujardini (Doyère, 1840) is there unanimous agree-ment on such a classification. This study has shownthat there is little consistency in the classification oftardigrades in Newfoundland and elsewhere in termsof the water content of the environment in which theyare found or the susceptibility to dessication of themosses which they inhabit.NICHOLS (1999) states that the relationship betweentardigrade species and moss species is not yet clear.While HOFFMANN (1987) found habitat preferencesbetween four tardigrade species and five moss speciesthe majority of studies (NELSON 1975; RAMAZZOTTI &MAUCCI 1983; KATHMAN & CROSS 1991); MILLER et al.(1996) found significant positive associations betweenthe three most common species of tardigrade and vari-ous bryophytes in their Antarctic study, whereas strongnegative associations were found between these threespecies and algae and lichens. The moss species fromwhich the tardigrades in this study were extracted havenot yet been identified and so it is not possible to say ifthere is any relationship between moss species andtardigrade species in Newfoundland. In his study ofBritish tardigrades WRIGHT (1991) suggests that thepositive associations he found between Milnesiumtardigradum Doyère, 1840 and two other species –

Zool. Anz. 240 (2001): 291–297© by Urban & Fischer Verlaghttp://www.urbanfischer.de/journals/zoolanz

* Contribution to the 8th International Symposium onTardigrada, Copenhagen, Denmark, 30 July–5 August 2000.

istic zonal distribution of the vegetation and animals.He has classified Polish tardigrades according to theelevations at which they are found. Lowland speciesdo not exceed an altitude of 200 m above sea level andonly rarely occur in upland regions; upland speciesoccur mostly in the range 201–500 m although theycan occur, though considerably more rarely, also in theneighbouring zones. Foreland species are found exclu-sively or most frequently in the zone 501–1000 m.Montane species have a distribution centre which liesabove 1000 m. DASTYCH (1988) further subdivides themontane species into three smaller groups in relation tothe timberline, namely subalpine, mesoalpine, andeualpine. Tychoalpine species are those which occur inaltitudinal zones from the lowland to the highestmountain zones.Since the highest elevation recorded in the presentstudy was only 460 m, it was predicted that altitudewould not have any significant effect on the distribu-tion of Newfoundland tardigrades. However, as isshown in Tab. 1, the distribution of several species isaffected by altitude. For the purposes of this analysisDASTYCH’s (1988) lowland zone was further subdivid-ed into two, namely 0–100 m, and 101–200 m. A num-ber of the more common Newfoundland species fitDASTYCH’s (1988) lowland category being found onlyat the two lowland altitudes including D. (D.) pingue,D. (D.) nodulosum (Ramazzotti, 1957), I. prosostomus,Murrayon dianeae (Kristensen, 1982), D. (A.) pror-sirostre (Thulin, 1928), H. convergens, and Ramaz-zottius sp. Several other species, found at only one ortwo locations, including Calohypsibius ornatus (Rich-ters, 1900), H. pallidus Thulin, 1911, H. dujardini,I. schaudinni (Richters, 1909), I. sattleri (= I. bako-nyiensis) (Richters, 1902), D. ramazzotti: (Robotti;1970), Hebesuncus conjungens Thulin, 1911, M. mon-tanus Murray, 1910, and Proechiniscus hanneae(Petersen, 1951) all occurred in the 0–100 m zone.H. microps Thulin, 1911 and I. lunulatus (Iharos,1966) were each found only at one site, both in the101–200 m zone, and so one cannot with any certaintysay that they do not occur at other altitudes as well.Echiniscus wendti (Richters, 1903) was the onlyspecies recorded solely in the 200 m+ zone but againthis species was only found at one site.A number of species were found in all three altitudinalzones including M. cf. hufelandi , M. cf. harmsworthi,D. (A.) scoticum, M. tardigradum, and M. intermedius,and could therefore, be regarded as tychoalpine speciesaccording to DASTYCH’s (1988) classification. A num-ber of species, therefore, including M. cf. hufelandi,M. cf. harmsworthi, M. tardigradum, M. intermediusand D. (A.) scoticum, can all be classified astychoalpine in both the present study and in DASTYCH’swork (1987, 1988). Platicrista angustata (Murray,

H. dujardini and Ramazzottius oberhauseri (Doyère,1840) – may be attributable to selective predation. Thispresent study, however, has not shown any positiverelationship between M. tardigradum and other tardi-grade species, although there may be a positive rela-tionship between the predatory species Macrobiotus cf.harmsworthi and M. cf. hufelandi and several othertardigrade species. MILLER et al. (1996) in their Antarc-tic study, found that D. (D.) chilinense Plate, 1888, H.antarcticus (Richters, 1904), and P. suillus (Ehrenberg,1853) were highly associated positively, but this mayhave been due to the faunal simplicity of the environ-ment which they were studying which yielded only sixtardigrade species in total. A preliminary analysis ofthe data from the present study does seem to suggestthat several species are negatively associated due totrophic overlap. Isohypsibius prosostomus Thulin,1928, for example, has not so far been found togetherwith either Diphascon (Adropion) scoticum (Murray,1905) or Minibiotus intermedius (Plate, 1888), andrarely with either D. (Diphascon) pingue (Marcus,1936) or H. convergens (Urbanowicz, 1925).

2. ALTITUDE AND TARDIGRADEDISTRIBUTION

There have been conflicting results in attempts to corre-late tardigrade distribution with altitude. Several stud-ies have shown that altitude can affect tardigrade distri-butions (RODRIGUEZ-RODA 1951; NELSON 1973, 1975;DASTYCH 1982, 1985, 1987, 1988; BEASLEY 1988),with most suggesting that an increase in altitude resultsin an increase in species richness. NELSON (1975) foundthat seven of twenty-one species were significantly cor-related with altitude ranges between 1450 and 2200 mon Roan Mountain, Tennessee. BEASLEY (1988) foundseveral correlations between altitude and tardigradedistributions in New Mexico. He separated severaltardigrades into their respective ranges; M. richtersiMurray, 1911 was found between 1820 and 2550 m;M. areolatus Murray, 1907 was found between 2550and 2900 m; Pseudechiniscus suillus (Ehrenberg, 1853)was found between 2900 and 3650 m; and M. tardi-gradum was found between 1820 and 2900 m, andagain above 4000 m. NICHOLS (1999), however, foundthat altitude had no effect on tardigrade distribution onDugger Mountain in Alabama. KATHMAN & CROSS

(1991) also found that tardigrade distribution was notinfluenced by altitude on mountains on VancouverIsland in British Columbia, Canada. DASTYCH (1988) states that the increase in altitudeabove sea-level is accompanied by a gradual decreasein temperature and humidity and it is mainly the jointaction of these two factors that results in the character-

292 M. COLLINS and L. BATEMAN

Ecological Distribution of Tardigrades in Newfoundland 293

Tab.

1.

Dis

trib

utio

n of

New

foun

dlan

d (N

) tar

digr

ades

by

altit

ude

with

Pol

ish

(P)

and

Spits

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S) d

ata

(Das

tych

198

5, 1

987)

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en fo

r com

pari

son.

New

foun

dlan

d Po

lish

Spits

berg

en

Spec

ies

0–10

1–20

1–50

1–0–

101–

201–

501–

1000

+m

0–10

1–20

1–50

1–10

00+

m>

100

m>

200

m>

500

m>

1000

+m

>10

0 m

>20

0 m

>50

0 m

>10

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m>

100

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200

m>

500

m>

1000

+m

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sis

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1905) and Mesocrista spitzbergense (Richters, 1903)were found in both the 0–100 m and 200 m + zones,but since both were only recorded from a few siteseach it is not possible to categorically state that theyare tychoalpine in nature.A number of species classified as tychoalpine byDASTYCH (1987, 1988) would so far be classified aslowland species in Newfoundland. These include D.(D.) pingue, I. prosostomus, D. (D.) prorsirostre, andH. convergens. Among the rarer Newfoundlandspecies, E. merokensis Richters, 1904, C. ornatus, andH. conjungens, are classified as montane species byDASTYCH (1987, 1988) but occur at lowland altitudesin this study. These findings reflect the more severe cli-matic conditions in Newfoundland than those existingin Poland and so many species found in the upper alti-tudinal zones in Poland are found in lower altitudes inNewfoundland.DASTYCH (1985) has also examined the effect of alti-tude on the distribution of tardigrades in West Spitsber-gen. Tab. 1 shows DASTYCH’s (1988) data for thosespecies also found in Newfoundland together with therelevant Newfoundland data. The data in this tableshow that a number of species which are found at lowaltitudes in Newfoundland have larger ranges of alti-tude in Spitsbergen. Among the more common New-foundland species, for example, H. convergens is onlyfound at the lowest altitudes (0–100 m) whereas inSpitsbergen it occurs from sea level to the highestmountain peaks. I. prosostomus only occurs in thelower altitudinal zones (0–200 m) in Newfoundlandwhereas it occurs from sea level to 700 m in Spitsbergen.Among the rarer Newfoundland species, I. sattleri,H. dujardini, H. pallidus, E. merokensis, and C. ornatushave so far only been found at much lower altitudesthan in Spitsbergen. H. conjungens which has onlybeen found at one site so far in Newfoundland in the0–100 m zone occurs in much higher elevations(701–1600 m) in Spitsbergen.It seems then that a number of species common to bothNewfoundland and Spitsbergen occur at much loweraltitudes in the former. Just as a comparison of theNewfoundland and Polish data (DASTYCH 1988) sug-gest that the environmental conditions are harsher inthe former for similar altitudes, the comparison ofNewfoundland and Spitsbergen data suggests thatthe environmental conditions existing in Newfound-land are likely to be harsher than those in Spitsbergen.However this is not the case since the Spitsbergensampling sites were at latitudes between 76 and81 degrees north, while the Newfoundland sitesoccur between 44 and 51 degrees north [the meanannual temperature for St. John’s, Newfoundland is+5.0 degrees Celsius, while that for Spitsbergen is –4.0(OnLineWeather.Com – www.onlineweather.com)].

The reasons for the Newfoundland species occurring atlower altitudes than in Spitsbergen are presentlyunknown.In his studies DASTYCH (1988) concluded that the mostfavourable altitude for tardigrades in Poland is con-tained in the higher altitudes between 500 and 2000 mabove sea-level, which includes the foreland as well asthe lower and middle parts of the mountains. Herecorded a total of 69 species above 500 m, and only55 below this altitude. He points out that his Polishstudies confirm the findings of RODRIGUEZ-RODA

(1951) who studied the effect of altitude on the tardi-grade fauna of Spain and also noticed the greatestnumber of species in the zone 1000–2000 m above sealevel, with considerably fewer species in the ranges500–1000 m and 2000–3000 m, and the smallest num-ber between 0 and 500 m. It is interesting to note, how-ever, that DASTYCH (1985) recorded a marked decreasein the number of tardigrade species with increasingaltitude on West Spitsbergen, with the greatest numberof species in the lowest regions (40 species in the low-est areas and only 15 in the higher areas). BEASLEY

(1988) in his study of tardigrades in New Mexico alsofound that there was a reduction of species withincreasing altitude (beginning with 5000 m), and thatthe total number of tardigrades and the average numberof individuals per sample also decreased with increas-ing altitude. NICHOLS (1999) in his study on DuggerMountain, Alabama found no significant correlationbetween tardigrade distributions and altitude.The data in Tab. 2 show that in Newfoundland there isa general decrease in both the total number of speciesand the mean number of species at each site, withincreasing altitude, although it is important to note thatno sites above 460 m were sampled in this presentstudy. While differing from the findings of RODRIGUEZ-RODA (1951), DASTYCH (1988), NELSON (1975) andNICHOLS (1999) the Newfoundland figures supportDASTYCH’S (1985) findings on West Spitsbergen andBEASLEY’S (1988) findings in New Mexico that speciesrichness decreases with increasing altitude. What isperhaps surprising in the Newfoundland situation isthat this decline in species richness begins at such lowaltitudes above sea level (28 species in the 0–100 m


Tab. 2. Species richness and altitude.

Altitude Total number Mean numberof species found of tardigradeat each altitude species at each site

0–>100 m 28 2.75101–>200 m 15 1.75200 + m 8 1.88

zone; 15 in the 101–200 m zone; and only 8 above 200m). Even in DASTYCH’S (1985) Spitsbergen study therewas only a small drop in total number of species (from40 to 35) between the 0–100 and 101–200 m zones.

3. TYPE OF BEDROCK ANDTARDIGRADE DISTRIBUTION

In a number of studies DASTYCH (1980, 1987, 1988)has shown that the tardigrades in Poland can be catego-rized by the degree of their association with specifickinds of rock. DASTYCH’s (1988) categories are eucal-ciphilous – species found exclusively on alkaline car-bonate rocks, polycalciphilous – species with a verystrong attachment to carbonate rocks, mesocalci-philous – constituting an intermediate group, oligical-ciphilous – strongly attached to non-carbonate rocks,and acalciphilous – found exclusively on non-carbon-ate rocks. He further subdivided the mesocalciphilousgroup into two smaller groups, namely those sightly

more frequent on carbonate rocks (type A), and speciesslightly more frequent on non-carbonate rocks(type B).Each Newfoundland sampling site was located on ageological survey map and was then classified as beingon a carbonate or non-carbonate rock. Each specieswas then allocated to one of DASTYCH’s 1988 groupsand this information is displayed in Tab. 3 whichshows the grouping for each Newfoundland speciestogether with the Polish and Spitsbergen designationsfor that same species. In only one case, that of D. (A.)scoticum, do the Newfoundland and Polish designa-tions concur. In most other cases the Newfoundlanddesignations were one group closer to the non-carbon-ate end of the spectrum as compared with the Polishdesignation for the same species. For instance both M.cf. hufelandi and M. intermedius are classified asmesocalciphilous in Poland, but are both oligocalci-philous in Newfoundland, while M. cf. harmsworthiand I. prosostomus are mesocalciphilous type A inPoland, but are mesocalciphilous type B in Newfound-


Tab. 3. Classification of Newfoundland (N) tardigrades by bedrock type (Polish – P; and Spitsbergen – S – designations aregiven for comparison).

Species Eucal Polycal MesoA MesoB Oligo Acal

Echiniscus merokensis P S N*E. wendti N* S PProechiniscus hanneae N*Macrobiotus cf. harmsworthi P N* SM. cf. hufelandi S P NM. montanus N*Minibiotus intermedius P N, SMurrayon dianeae NCalohypsibius ornatus P N*Hypsibius convergens P N, SH. dujardini N* P SH. microps P N*H. pallidus S P N*Isohypsibius sattleri N*, S PI. lunulatus N*I. prosostomus P N SI. schaudinni N*Microhypsibius sp. N*Ramazzottius sp. NDiphascon (A.) prorsirostre P ND. (A.) scoticum S N, PD. (D.) nodulosum N*D. (D.) pingue P N SD. (D.) ramazzottii N*Hebesuncus conjungens N*, SMesocrista spitzbergense N P, SPlaticrista angustata N S PMilnesium tardigradum P, S N

* Occurs at only one or a few locations

land. It would seem that the species in Newfoundlandcan survive in less alkaline conditions than is the casein Poland.The results of the comparison between carbonate rockpreferences for Newfoundland and Spitsbergen are notas clear. In some cases, such as for example M. inter-medius and H. convergens, the designations for New-foundland and Spitsbergen are identical. In other cases,such as with M. cf. hufelandi the Spitsbergen speci-mens occur in less acidic areas while in other casessuch as M. cf. harmsworthi, I. prosostomus, D. (D.)pingue, M. spitsbergense, and P. angustata the Spits-bergen specimens occur in more acidic areas. Overall the Newfoundland carbonate sites had a highermean number of tardigrade species (mean = 3.08) thanthe non-carbonate sites (mean = 2.30). This is consis-tent with DASTYCH’s (1985) findings in Spitsbergenwhere the carbonate sites also had a greater number ofspecies and specimens.

4. CONCLUSIONS

In summary then, the results of this study suggest thatthe ecological distribution of tardigrades on the islandof Newfoundland is influenced by abiotic factors suchas altitude and type of bedrock. It seems that evensmall differences in altitude may be more important inlimiting tardigrade distribution in Newfoundland thanhas been noted elsewhere. Further investigation isrequired to determine whether water content of thehabitat, and ability to withstand dessication, and fac-tors such as inter-specific competition, and the abilityto withstand predation by species such as M. tardi-gradum and M. cf. harmsworthi are also influential.Further analysis of the results needs to be conducted tosee whether or not these hypotheses will stand the testof statistical analysis.

Acknowledgements. We gratefully acknowledge the consid-erable assistance we have received from Dr. Diane Nelson,Department of Biological Sciences, East Tennessee StateUniversity, Johnson City, Tennessee, USA. We would alsolike to express our thanks to Mr. Nigel Marley, University ofPlymouth, UK, and Ms. Sandra Claxton, School of Biologi-cal Sciences, Macquarie University, Ryde, New South Wales,Australia, for their help in the identification of a number ofspecimens. We also acknowledge the assistance of Mr. RoyFicken of the Biology Department, Memorial University ofNewfoundland for his help with the operation of the depart-mental research microscope and the associated photography.Our thanks are also due to Mr. Doug Piercy of the CornerBrook Division of the Canadian Forestry Service, NaturalResources Canada for obtaining and imaging the G.I.S. data.We would also like to express our considerable gratitude totwo of our student assistants, Ms. Julianne Mayo and Ms.

Lori Garland, who have spent many hours extracting, mount-ing, measuring and identifying our specimens. Without theirhelp and enthusiasm we would not have progressed as rapid-ly as we have.

REFERENCES

BATEMAN, L. & COLLINS, M. (2001): The tardigrades of New-foundland, Canada. Zool. Anz. 240: 223–232.

BEASLEY, C.W. (1978): The tardigrades of Oklahoma. Am.Midl. Nat. 99: 128–141.

BEASLEY, C.W. (1988): Altitudinal distribution of Tardigradaof New Mexico with the description of a new species. Am.Midl. Nat. 120: 436–440.

CASKEY, D.S. (1971): Tardigrada of Texas. UnpublishedMSc. Thesis. 50 pp. Lamar University, Beaumont, Texas,USA.

DASTYCH, H. (1980): Tardigrada of Tetra National Park,Poland. Monograf. Faun. Pol. 9: 5–232.

DASTYCH, H. (1982): An annotated list of Alaskan Tardigra-da. Pol. Polar Res. 3: 95-102.

DASTYCH, H. (1985): West Spitsbergen Tardigrada. Acat.Zool. Cracov. 28: 169–214.

DASTYCH, H. (1987): Altitudinal distribution of Tardigrada inPoland. Pp. 169–176 in BERTOLANI, R. (ed) (1987): Biolo-gy of Tardigrades: Selected Symposia and Monographs.380 pp. U.Z.I. vol. 1. Mucchi, Modena.

DASTYCH, H. (1988): The Tardigrada of Poland. Monograf.Faun. Pol. 16: 1–255.

HALLAS, T.E., & YEATES, G.W. (1972): Tardigrada of the soiland litter of a Danish beech forest. Pedobiol. 12: 287–304.

HOFMANN, I. (1987): Habitat preference of the most frequentmoss-living Tardigrada in the area of Giessen (Hessen).Pp. 211–216 in BERTOLANI, R. (ed), Biology of Tardi-grades: Selected Symposia and Monographs. U.Z.I. vol. 1.Mucchi, Modena.

KATHMAN, R.D. & CROSS, S.F. (1991): Ecological distribu-tion of moss-dwelling tardigrades on Vancouver Island,British Columbia, Canada. Can. J. Zool. 69: 122–129.

KINCHIN I. (1994): The Biology of Tardigrades. 186 pp.,Portland Press Ltd., London.

MILLER, W.R., MILLER, J.D., & HEATWOLE, H. (1996): Tardi-grades of the Australian Antarctic Territories: the Wind-mill Islands, East Antarctica. Zool. J. Linn. Soc. London116: 175-184.

NELSON, D.R. (1973): Distribution of tardigrades on RoanMountain, Tennessee-North Carolina. Unpublished PhDThesis. 168 pp. University of Tennessee, Knoxville, Ten-nessee.

NELSON, D.R. (1975): Ecological distribution of tardigradeson Roan Mountain, Tennessee-North Carolina. Mem. Ist.Ital. Idrobiol. (Suppl.). 32: 225–276.

NICHOLS, P.B. (1999): The ecological distribution of theTardigrada on Dugger Mountain (ne Alabama) withrespect to seasonal and altitudinal variation. UnpublishedMSc Thesis. 139 pp. Jacksonville State University, Jack-sonville, Alabama.


Corresponding author: Michael A.J. COLLINS, Biology De-partment, Memorial University of Newfoundland, St. John’s,Newfoundland, Canada A1B 3X9; Tel.: (709) 737-7505;Fax: (709) 737-3018; e-mail [email protected]

Received: 29. 10. 2000Reviewed: 18. 07. 2001Accepted: 13. 09. 2001Corresponding Editor: Reinhardt Møbjerg KRISTENSEN

RAMAZZOTTI, G. & MAUCCI, W. (1983): Il phylum Tardigra-da. Terza Edizione. Mem. Ist. Ital. Idrobiol. 41: 1–1012.(BEASLEY, C.W., English translation).

RODRIGUEZ-RODA, (1951): Algunos datos sobre la distribu-cion de los tardigrados espanoles. Bol. Real Soc. Esp.Hist. Nat., Sec. Biol. 49: 75–83.

WRIGHT, J.C. (1991): The significance of four xeric parame-ters in the ecology of terrestrial Tardigrada. J. Zool. Soc.Lond. 224: 59–77.


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The Ecological Distribution of Tardigrades in Newfoundland