Current status of the Tardigrada: Evolution and ecology

Integrative and Comparative Biology

Volumn 42, Issue 3, 2002, Pages 652-659

  Nelson, Diane R ^a  

^a EAST TENNESSEE STATE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ARTHROPODA; INVERTEBRATA; TARDIGRADA;

EID: 0036625891     PISSN: 00031569     EISSN: None     Source Type: Journal    
DOI: 10.1093/icb/42.3.652     Document Type: Conference Paper

References (102)

1. Aguinaldo, A., J. Turbeville, L. Linford, M. Rivera, J. Garey, R. Raff, and J. Lake. 1997. Evidence for a clade of nematodes, arthropods, and other moulting animals. Nature 387:489-493.
2. Bello, G. and S. de Zio Grimaldi. 1998. Phylogeny of the genera of the Stygarctidae and related families (Tardigrada: Heterotardigrada). Zool. Anz. 237:171-183.
3. Bertolani, R. 1982. 15. Tardigradi. Guide per il Riconoscimento delle Specie Animali delle Acque Interne Italiane, pp. 104. Consiglio Nazionale Delle Ricerche, Verona, Italy.
4. Bertolani, R. (ed.) 1987a. Biology of Tardigrades. Proceedings of the Fourth International Symposium on the Tardigrada, September 1985, Modena, Italy. Selected Symposia and Monographs 1:1-380. Mucchi, Modena, Italy.
5. Bertolani, R. 1987b. Sexuality, reproduction, and propagation in tardigrades. In R. Bertolani (ed.), Biology of Tardigrades. Proceedings of the Fourth International Symposium on the Tardigrada, September 1985, Modena, Italy. Selected Symposia and Monographs 1:93-101. Mucchi, Modena, Italy.
6. Bertolani, R. and L. Rebecchi. 1993. A revision of the Macrobiotus hufelandi group (Tardigrada, Macrobiotidae), with some observations on the taxonomic characters of eutardigrades. Zool. Scripta 22:127-152.
7. Bertolani, R. and L. Rebecchi. 1996. The tardigrades of Emilia (Italy). II. Monte Rondinaio. A multihabitat study on a high altitude valley of the northern Apennines. In S. McInnes and D. Norman (eds.), Tardigrade biology. Proceedings of the sixth international symposium on Tardigrada, August 1994, Cambridge, England. Zool. J. Linn. Soc. 116:3-12.
8. Bertolani, R. and L. Rebecchi. 1999. Tardigrada. In E. Knobil and J. D. Neill (eds.), Encyclopedia of Reproduction, Vol. 4, pp. 703-718. Academic Press, San Diego.
9. Bertolani, R., L. Rebecchi, and G. Beccaccioli. 1990. Dispersal of Ramazzottius and other tardigrades in relation to type of reproduction. Invert. Reprod. Develop. 18:153-157.
10. Briones, M., P. Ineson, and T. Piearce. 1997. Effects of climate change on soil fauna; responses of enchytraeids, Diptera larvae and tardigrades in a transplant experiment. Appl. Soil Ecol. 6:117-134.
11. Claxton, S. 1998. A revision of the genus Minibiotus (Tardigrada: Macrobiotidae) with descriptions of eleven new species from Australia. Records Aust. Mus. 50:125-160.
12. Claxton, S. 1999. Milnesioides exsertum gen. n. sp., a new tardigrade from Australia (Tardigrada: Milnesiidae). In H. Greven (ed.), Proceedings of the seventh international symposium on the Tardigrada, August 1997, Düsseldorf, Germany. Zool. Anz. 238:183-190.
13. Crisp, M. and R. Kristensen. 1983. A new marine interstitial eutardigrade from east Greenland, with comments on habitat and biology. Videnskabelige Meddelelser fra Dansk Naturhistorisk Forening 144:99-114.
14. Crowe, J. 1975. The physiology of cryptobiosis in tardigrades. In R. Higgins (ed.), International symposium on tardigrades, Pallanza, Italy, June 17-19, 1974. Mem. Ist. Ital. Idrobiol. 32(Suppl.):37-59.
15. Crowe, J., F. Hoekstra, and L. Crowe. 1992. Anhydrobiosis. Ann. Rev. Physiol. 54:579-599.
16. D'Addabbo Gallo, M., M. Morone De Lucia, and S. Grimaldi de Zio. 1987. Heterotardigrada of the Amendolara Shoal, High Ionian Sea. In R. Bertolani (ed.), Biology of Tardigrades. Proceedings of the Fourth International Symposium on the Tardigrada, September 1985, Modena, Italy. Selected Symposia and Monographs 1:93-101. Mucchi, Modena, Italy.
17. Dastych, H. 1993. Redescription of the cryoconital tardigrade Hypsibius klebelsbergi Mihelčič, 1959, with notes on the microslide collection of the late Dr. F. Mihelčič. Veröff. Mus. Ferdinandeum 73:5-12.
18. De Smet, W. and E. Van Rompu. 1994. Rotifera and Tardigrada from some cryoconite holes on a Spitspergen (Svalbard) glacier. Belgium J. Zool. 124:27-37.
19. Dewel, R. and W. Dewel. 1996. The brain of Echiniscus viridissimus Peterfi, 1956 (Heterotardigrada): A key to understanding the phylogenetic position of tardigrades and the evolution of the arthropod head. In S. McInnes and D. Norman (eds.), Tardigrade biology. Proceedings of the sixth international symposium on Tardigrada, August 1994, Cambridge, England. Zool. J. Linn. Soc. London 116:35-49.
20. Dewel, R. and W. Dewel. 1997. The place of tardigrades in arthropod evolution. In R. Fortey and R. Thomas (eds.), Arthropod Relationships, The Systematics Association Special Volume Series 55, pp. 109-125. Chapman & Hall, New York.
21. Dewel, R., D. R. Nelson, and W. Dewel. 1993. Tardigrada. In F. W. Harrison and M. E. Rice (eds.), Microscopic Anatomy of Invertebrates. Vol. 12, Onychophora, Chilopoda, and Lesser Protostomata, pp. 143-183. Wiley-Liss, New York.
22. Dewel, R., G. Budd, D. Castano, and W. Dewel. 1999. The organization of the subesophageal nervous system in tardigrades: Insights into the evolution of the arthropod hypostome and tritocerebrum. In H. Greven (ed.), Proceedings of the seventh international symposium on the Tardigrada, August 1997, Düsseldorf, Germany. Zool. Anz. 238:191-203.
23. Doyère, L. 1840. Mémoire sur les Tardigrades. Ann. Sci. Nat. (Paris), Zool., Ser. 2, 14:269-362.
24. Eernisse, D., J. Albert, and F. Anderson. 1992. Annelida and Arthropoda are not sister taxa: A phylogenetic analysis of spiralian metazoan morphology. Syst. Biol. 41:305-330.
25. Eibye-Jacobsen, J. 1996/97. New observations on the embryology of the Tardigrada. Zool. Anz. 235:201-216.
26. Eibye-Jacobsen, J. 1997. Development, ultrastructure and function of the pharynx of Halobiotus crispae Kristensen, 1982 (Eutardigrada). Acta Zool. 78:329-347.
27. Everitt, D. 1981. An ecological study of an Antarctic freshwater pool with particular reference to Tardigrada and Rotifera. Hydrobiologia 83:225-237.
28. Franceschi, T., M. Loi, and R. Pierantoni. 1962/63. Risultati di una prima indagine ecologica condotta su popolazioni di Tardigradi. Boll. Mus. Ist. Biol. Univ. Genova 32:69-93.
29. Garagna, S., L. Rebecchi, and A. Guidi. 1996. Genome size variation in Tardigrada. In S. McInnes and D. Norman (eds.), Tardigrade biology. Proceedings of the sixth international symposium on Tardigrada, August 1994, Cambridge, England. Zool. J. Linn. Soc. 116:115-121.
30. Garey, J., M. Krotec, D. R. Nelson, and J. Brooks. 1996. Molecular analysis supports a tardigrade-arthropod association. Invert. Biol. 115:79-88.
31. Garey, J., D. R. Nelson, L. Mackey, and J. Li. 1999. Tardigrade phylogeny: Congruency of morphological and molecular evidence. In H. Greven (ed.), Proceedings of the seventh international symposium on the Tardigrada, August 1997, Düsseldorf, Germany. Zool. Anz. 238:205-210.
32. Giribet, G., S. Carranza, J. Baguñà, M. Riutort, and C. Ribera. 1996. First molecular evidence for the existence of a Tardigrada + Arthropoda clade. Mol. Biol. Evol. 13:76-84.
33. Greven, H. (ed.) 1999. Proceedings of the seventh international symposium on the Tardigrada, August 1997, Düsseldorf, Germany. Zool. Anz. 238(3/4):133-346.
34. Grimaldi de Zio, S., M. D'Addabbo Gallo, and M. Morone De Lucia. 1983. Marine tardigrades ecology. Oebalia 9:15-31.
35. Grimaldi de Zio, S., M. D'Addabbo Gallo, and R. Pietanza. 2000. Two new sub-Antarctic Echiniscoididae from Marion Island (Heterotardigrada, Echiniscoidea). Ital. J. Zool. 67:221-228.
36. Grøngaard, A., P. Pugh, and S. McInnes. 1999. Tardigrades, and other cryoconite biota, on the Greenland Ice Sheet. In H. Greven (ed.), Proceedings of the seventh international symposium on the Tardigrada, August 1997, Düsseldorf, Germany. Zool. Anz. 238:211-214.
37. Guidetti, R. 1998. Two new species of Macrobiotidae (Tardigrada, Eutardigrada) from the United States of America, and some taxonomic considerations of the genus Murrayon. Proc. Biol. Soc. Wash. 111(3):663-673.
38. Guidetti, R., R. Bertolani, and D. R. Nelson. 1999. Ecological and faunistic studies on tardigrades in leaf litter of beech forests. In H. Greven (ed.), Proceedings of the seventh international symposium on the Tardigrada, August 1997, Düsseldorf, Germany. Zool. Anz. 238:215-223.
39. Guidi, A. and L. Rebecchi. 1996. Spermatozoan morphology as a character for tardigrade systematics: Comparisons with sclerified parts of animals and eggs in eutardigrades. In S. McInnes and D. Norman (eds.), Tardigrade biology. Proceedings of the sixth international symposium on Tardigrada, August 1994, Cambridge, England. Zool. J. Linn. Soc. 116:101-113.
40. Hallas, T. E. 1975. A mechanical method for the extraction of Tardigrada. In R. Higgins (ed.), International symposium on tardigrades, Pallanza, Italy, June 17-19, 1974. Mem. Ist. Ital. Idrobiol. 32(Suppl.):153-158.
41. Hallas, T. E. and G. W. Yeates. 1972. Tardigrada of the soil and litter of a Danish beech forest. Pedobiologia 12:287-304.
42. Higgins, R. (ed.) 1975. International symposium on tardigrades, Pallanza, Italy, June 17-19, 1974. Mem. Ist. Ital. Idrobiol. 32(Suppl.):1-469.
43. Ito, M. 1999. Ecological distribution, abundance and habitat preference of terrestrial tardigrades in various forests on the northern slope of Mt. Fuji, central Japan. In H. Greven (ed.), Proceedings of the seventh international symposium on the Tardigrada, August 1997, Düsseldorf, Germany. Zool. Anz. 238:225-234.
44. Kathman, R. D. and D. R. Nelson. 1987. Population trends in the aquatic tardigrade Pseudobiotus augusti (Murray). In R. Bertolani (ed.), Biology of Tardigrades. Proceedings of the Fourth International Symposium on the Tardigrada, September 1985, Modena, Italy. Selected Symposia and Monographs 1:155-168. Mucchi, Modena, Italy.
45. Kinchin, I. M. 1994. The Biology of Tardigrades. Portland Press, London. 186 pp.
46. Kristensen, R. 1982a. New aberrant eutardigrades from homothermic springs on Disko Island, West Greenland. In D. R. Nelson (ed.), Proceedings of the Third International Symposium on the Tardigrada, August 3-6, 1980, Johnson City, Tennessee, pp. 203-220. East Tennessee State University Press, Johnson City.
47. Kristensen, R. 1982b. The first record of cyclomorphosis in Tardigrada based on a new genus and species from Arctic meiobenthos. Z. Zool. Syst. Evolut.-forsch. 20:249-270.
48. Kristensen, R. 1987. Generic revision of the Echiniscidae (Heterotardigrada), with a discussion of the origin of the family. In R. Bertolani (ed.), Biology of Tardigrades. Proceedings of the Fourth International Symposium on the Tardigrada, September 1985, Modena, Italy. Selected Symposia and Monographs 1:261-335. Mucchi, Modena, Italy.
49. Kristensen, R. (ed.) 2001. Eighth international symposium on Tardigrada, Copenhagen, 30 july-5 august 2000. Zool. Anz. 240(3/4).
50. Kristensen, R. and T. Hallas. 1980. The tidal genus Echiniscoides and its variability, with erection of Echiniscoididae fam. n. (Tardigrada). Zool. Scripta 9:113-127.
51. Kristensen, R. and R. Higgins. 1984a. Revision of Styraconyx (Tardigrada: Halechiniscidae), with descriptions of two new species from Disko Bay, West Greenland. Smithsonian Contrib. Zool. 391:1-40.
52. Kristensen, R. and R. Higgins. 1984b. A new family of Arthrotardigrada (Tardigrada: Heterotardigrada) from the Atlantic coast of Florida, U.S.A. Trans. Am. Microsc. Soc. 103:295-311.
53. Kristensen, R. and B. Neuhaus. 1999. The uttrastructure of the tardigrade cuticle with special attention to marine species. In H. Greven (ed.), Proceedings of the seventh international symposium on the Tardigrada, August 1997, Düsseldorf, Germany. Zool. Anz. 238:261-281.
54. Manicardi, G. and R. Bertolani. 1987. First contribution to the knowledge of alpine grassland tardigrades. In R. Bertolani (ed.), Biology of Tardigrades. Proceedings of the Fourth International Symposium on the Tardigrada, September 1985, Modena, Italy. Selected Symposia and Monographs 1:177-185. Mucchi, Modena, Italy.
55. McInnes, S. 1994. Zoogeographic distribution of terrestrial/freshwater tardigrades from current literature. J. Nat. Hist. 28:257-352.
56. McInnes, S. and J. C. Ellis-Evans. 1987. Tardigrades from maritime Antarctic freshwater lakes. In R. Bertolani (ed.), Biology of Tardigrades. Proceedings of the Fourth International Symposium on the Tardigrada, September 1985, Modena, Italy. Selected Symposia and Monographs 1:111-123. Mucchi, Modena, Italy.
57. McInnes, S. and J. C. Ellis-Evans. 1990. Micro-invertebrate community structure within a maritime Antarctic lake. Proc. N.I.P.R. Symp. Polar Biol. 3:179-189.
58. McInnes, S. and D. Norman. (eds.) 1996. Tardigrade biology. Proceedings of the sixth international symposium on Tardigrada, August 1994, Cambridge, England. Zool. J. Linn. Soc. 116:1-243.
59. McInnes, S. and P. Pugh. 1998. Biogeography of limno-terrestrial Tardigrada, with particular reference to the Antarctic fauna. J. Biogeography 25:31-36.
60. McInnes, S. and P. Pugh. 1999. Zonation in Antarctic lake-dwelling benthic meiofauna, with emphasis on the Tardigrada. In H. Greven (ed.), Proceedings of the seventh international symposium on the Tardigrada, August 1997, Düsseldorf, Germany. Zool. Anz. 238:283-288.
61. Miller, W. R. and R. Kristensen. 1999. Tardigrades of the Australian Antarctic: A new species of the marine genus Echiniscoides from Macquarie Island, Subantarctica. In H. Greven (ed.), Proceedings of the seventh international symposium on the Tardigrada, August 1997, Düsseldorf, Germany. Zool. Anz. 238:289-294.
62. Møbjerg, N. and C. Dahl. 1996. Studies on the morphology and ultrastructure of the Malpighian tubules of Halobiotus crispae Kristensen, 1982 (Eutardigrada). In S. McInnes and D. Norman (eds.), Tardigrade biology. Proceedings of the sixth international symposium on Tardigrada, August 1994, Cambridge, England. Zool. J. Linn. Soc. 116:85-99.
63. Moon, S. and W. Kim. 1996. Phylogenetic position of the Tardigrada based on the 18S ribosomal RNA gene sequences. In S. McInnes and D. Norman (eds.), Tardigrade biology. Proceedings of the sixth international symposium on Tardigrada, August 1994, Cambridge, England. Zool. J. Linn. Soc. 116:61-69.
64. Morgan, C. 1977. Population dynamics of two species of Tardigrada, Macrobiotus hufelandi (Schultze) and Echiniscus (Echiniscus) testudo (Doyère), in roof moss from Swansea. J. Anim. Ecol. 46:263-279.
65. Nelson, D. R. (ed.) 1982a. Proceedings of the Third International Symposium on the Tardigrada, August 3-6, 1980, Johnson City, Tennessee, pp. 236. East Tennessee State University Press, Johnson City.
66. Nelson, D. R. 1982b. Developmental biology of the Tardigrada. In F. Harrison and R. Cowden (eds.), Developmental Biology of Freshwater Invertebrates, pp. 363-368. Alan R. Liss, New York.
67. Nelson, D. R. 2001. Tardigrada. In J. Thorp and A. Covich (eds.), Ecology and Classification of North American Freshwater Invertebrates, 2nd Ed., pp. 527-550. Academic Press, San Diego.
68. Nelson, D. R. and R. Higgins. 1990. Tardigrada. In D. Dindal (ed.), Soil Biology Guide, pp. 393-420. John Wiley & Sons, Inc., New York.
69. Nelson, D. R., C. J. Kincer, and T. C. Williams. 1987. Effects of habitat disturbances on aquatic tardigrade populations. In R. Bertolani (ed.), Biology of Tardigrades. Proceedings of the Fourth International Symposium on the Tardigrada, September 1985, Modena, Italy. Selected Symposia and Monographs 1:141-153. Mucchi, Modena, Italy.
70. Nelson, D. R. and N. Marley. 2000. The biology and ecology of lotic Tardigrada. Freshwater Biol. 44:93-108.
71. Nielsen, C. 1995. Animal Evolution. Interrelationships of the Living Phyla. Oxford University Press, Oxford.
72. Nielsen, C., N. Scharff, and D. Eibye-Jacobsen. 1996. Cladistic analyses of the animal kingdom. Biol. J. Linn. Soc. 57:285-410.
73. Pilato, G. 1979. Correlations between cryptobiosis and other biological characteristics in some soil animals. Boll. Zool. 46:319-332.
74. Pilato, G. 1987. Revision of the genus Diphascon Plate, 1889, with remarks on the subfamily Itaquasconinae (Eutardigrada, Hypsibiidae). In R. Bertolani (ed.), Biology of tardigrades. Proceedings of the fourth international symposium on the Tardigrada, September 1985, Modena, Italy. Selected Symposia and Monographs 1:337-357. Mucchi, Modena, Italy.
75. Pugh, P. and S. McInnes. 1998. The origin of Arctic terrestrial and freshwater tardigrades. Polar Biol. 19:177-182.
76. Ramazzotti, G. 1962. II Phylum Tardigrada. Mem. Ist. Ital. Idrobiol. 14:1-595.
77. Ramazzotti, G. and W. Maucci. 1983. II Phylum Tardigrada. III edizione riveduta e aggiornata. Mem. Ist. Ital. Idrobiol. 41:1-1012. [Note: an English translation is available from Dr. Clark Beasley, Biology Dept., McMurry University, Abilene, TX 79697.]
78. Ramløv, H. and P. Westh. 1992. Survival of the cryptobiotic eutardigrade Adorybiotus coronifer during cooling to - 196°C: Effect of cooling rate, trehalose level, and short term acclimation. Cryobiology 29:125-130.
79. Rebecchi, L. and R. Bertolani. 1988. New cases of parthenogenesis and polyploidy in the genus Ramazzottius (Tardigrada, Hypsibiidae) and a hypothesis concerning their origin. Invert. Reprod. Develop. 14:187-196.
80. Rebecchi, L. and R. Bertolani. 1994. Maturative pattern of ovary and testis in eutardigrades of freshwater and terrestrial habitats. Invert. Reprod. Develop. 26:107-117.
81. Rebecchi, L. and D. R. Nelson. 1998. Evaluation of a secondary sex character in eutardigrades. Invert. Biol. 117(3):194-198.
82. Rebecchi, L., A. Guidi, and R. Bertolani. 2000. Tardigrada. In B. G. M. Jamieson (ed.), Vol. 6, Progress in Male Gamete Ultrastructure and Phylogeny, pp. 267-291. Oxford and IBH, New Delhi.
83. Renaud-Mornant, J. 1982. Species diversity in marine Tardigrada. In D. R. Nelson (ed.), Proceedings of the Third International Symposium on the Tardigrada, August 3-6, 1980, Johnson City, Tennessee, pp. 149-177. East Tennessee State University Press, Johnson City.
84. Renaud-Mornant, J. 1988. Tardigrada. In R. Higgins and J. Thiel (eds.), Introduction to the Study of Meiofauna, pp. 357-364. Smithsonian Institution Press, Washington, D.C.
85. Renaud-Mornant, J. and L. Pollock. 1971. A review of the systematics and ecology of marine Tardigrada. Smithsonian Contrib. Zool. 76:109-117.
86. Schuster, R. O., E. C. Toftner, and A. A. Grigarick. 1977. Tardigrada of Pope Beach, Lake Tahoe, California. Wasmann J. Biol. 35:115-136.
87. Schuster, R. O., D. R. Nelson, A. A. Grigarick, and D. Christenberry. 1980. Systematic criteria of the Eutardigrada. Trans. Am. Microsc. Soc. 99:284-303.
88. Sømme, L. 1996. Anhydrobiosis and cold tolerance in tardigrades. Eur. J. Entomol. 93:349-357.
89. Steiner, W. 1994a. The influence of air pollution on moss-dwelling animals: 1. Methodology and composition of flora and fauna. Rev. Suisse Zool. 101:533-556.
90. Steiner, W. 1994b. The influence of air pollution on moss-dwelling animals: 2. Aquatic fauna with emphasis on Nematoda and Tardigrada. Rev. Suisse Zool. 101:699-724.
91. Steiner, W. 1994c. The influence of air pollution on moss-dwelling animals: 4. Seasonal and long-term fluctuations of rotifer, nematode and tardigrade populations. Rev. Suisse Zool. 101:1017-1031.
92. 2 and exposure experiments. Rev. Suisse Zool. 102:13-40.
93. Strayer, D., D. R. Nelson, and E. B. O'Donnell. 1994. Tardigrades from shallow groundwaters in southeastern New York, with the first record of Thulinia from North America. Trans. Am. Microsc. Soc. 113:325-332.
94. Van Rompu, E. A., W. H. De Smet, and L. Beyens. 1992. Contributions to the Tardigrada of the Canadian High-Arctic 1. Freshwater tardigrades from Devon Island, Northwest Territories. Can. Field-Nat. 106:303-310.
95. Villora-Moreno, S. and S. Grimaldi de Zio. 1996. New records of marine Tardigrada in the Mediterranean Sea. In S. McInnes and D. Norman (eds.), Tardigrade biology. Proceedings of the sixth international symposium on Tardigrada, August 1994, Cambridge, England. Zool. J. Linn. Soc. 116:149-166.
96. Walz, B. 1982. Molting in Tardigrada. A review including new results on cuticle formation in Macrobiotus hufelandi. In D. R. Nelson (ed.), Proceedings of the Third International Symposium on the Tardigrada, August 3-6, 1980, Johnson City, Tennessee, pp. 129-147. East Tennessee State University Press, Johnson City.
97. Wȩglarska, B. (ed.) 1979. Second international symposium on tardigrades, Kraków, Poland, July 28-30, 1977. Zeszyty Naukowe Uniwersytetu Jagiellonskiego, Prace Zoologiczne, 25:1-197.
98. Westh, P. and R. Kristensen. 1992. Ice formation in the freeze-tolerant eutardigrades Adorybiotus coronifer and Amphibolus nebulosus studied by differential scanning calorimetry. Polar Biol. 12:693-699.
99. Westh, P., J. Kristiansen, and A. Hvidt. 1991. Ice-nucleating activity in the freeze-tolerant tardigrade Adorybiotus coronifer. Comp. Biochem. Physiol. 99A:401-404.
100. Wiederhöft, H. and H. Greven. 1996. The cerebral ganglia of Milnesium tardigradum Doyère (Apochela, Tardigrada): Three dimensional reconstruction and notes on their ultrastructure. In S. McInnes and D. Norman (eds.), Tardigrade biology. Proceedings of the sixth international symposium on Tardigrada, August 1994, Cambridge, England. Zool. J. Linn. Soc. 116:71-84.
101. Wiederhöft, H. and H. Greven. 1999. Notes on head sensory organs of Milnesium tardigradum Doyère, 1840 (Apochela, Eutardigrada). In H. Greven (ed.), Proceedings of the seventh international symposium on the Tardigrada, August 1997, Düsseldoff, Germany. Zool. Anz. 238:338-346.
102. Wright, J. C., P. Westh, and H. Ramløv. 1992. Cryptobiosis in Tardigrada. Biol. Rev. 67:1-29.