To date, only morphological and anatomical descriptions of microwhip scorpions (Arachnida: Palpigradi) have been published. This very rare group is enigmatic not only in its relationships to other arachnids, but especially due to the fact that these animals dwell only underground (in caves, soil, and interstitial spaces). We observed the curious feeding habit of the microwhip scorpion Eukoenenia spelaea over the course of one year in Ardovská Cave, located in Slovakia's Karst region. We chose histology as our methodology in studying 17 specimens and based it upon Masson's triple staining, fluorescent light and confocal microscopy. Single-celled cyanobacteria (blue-green algae) were conspicuously predominant in the gut of all studied palpigrades. Digestibility of the consumed cyanobacteria was supported by the presence of guanine crystals, glycogen deposits and haemocytes inside the palpigrade body. Cyanobacteria, the oldest cellular organisms on Earth, are very resistant to severe conditions in caves, including even darkness. Therefore, the cyanobacteria are able to survive in dark caves as nearly heterotrophic organisms and are consumed by cave palpigrades. Such feeding habit is extraordinary within the almost wholly predacious orders of the class Arachnida, and particularly so due to the type of food observed.

Department of Zoology Faculty of Science Charles University Prague Czech Republic

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Kováč L' (1999) Eukoenenia spelaea (Peyerimhoff, 1902) – a cave dwelling palpigrade (Arachnida, Palpigradida) from the Slovak Karst. In: Tajovský K, Pižl V, Soil Zoology in Central Europe. České Budějovice: AS CR. pp.157–160.

Kováč L', Mock A, L'uptáčik P, Palacios-Vargas JG (2002) Distribution of Eukoenenia spelaea (Peyerimhoff, 1902) (Arachnida, Palpigradida) in the Western Carpathians with remarks on its biology and behaviour. In: Tajovský K, Balík V, Pižl V Studies on Soil Fauna in Central Europe. České Budějovice: AS CR. pp. 93–99.

Roewer CF (1943) Palpigradi In: Bronns Klassen und Ordnungen des Tierreichs, vol. 5 , chap.4, Leipzig. pp.640–707.

Hammen van der L (1982) Comparative studies in Chelicerata II. Epimerata (Palpigradi and Actinotrichida). Zool Verhand 196: 1–70.

Christian E (1998) Eukoenenia austriaca from the catacombs of St. Stephen's Cathedral in the centre of Vienna and the distribution of palpigrades in Austria (Arachnida: Palpigradida: Eukoeneniidae). Senckenb Biol 77: 241–245.

Monniot F (1966) Un Palpigrade interstitiel: Leptokoenenia scurra n. sp. Rev Ecol Biol Sol 3: 41–64.

Rucker A (1903) Further observations on Koenenia . Zool Jahrb Syst 14: 401–434.

Hammen van der L (1969) Notes on the mouthparts of Eukoenenia mirabilis (Grassi) (Arachnidea: Palpigradida). Zool Meded Leiden 44: 41–45.

Millot J (1942) Sur l'anatomie et l'histophysiologie de Koenenia mirabilis Grassi (Arachnida Palpigradi). Rev Franc Ent 9: 33–51.

Millot J (1943) Notes complémentaires sur l'anatomie, l'histologie et la répartition géographique en France de Koenenia mirabilis Grassi (Arachnida Palpigradi). Rev Franc Ent 9: 127–135.

Rowland JM, Sissom WD (1980) Report on a fossil Palpigrade from the Tertiary of Arizona, and a review of the morphology and systematics of the order (Arachnida, Palpigradida). J Arachnol 8: 69–86.

Imms AD (1973) A general textbook of entomology. ed 9. London: Chapman and Hill. 886 p.

Alberti G (1979) Zur Feinstruktur der Spermien und Spermiocytogenese von Prokoenenia wheeleri (Rucker, 1901) (Palpigradi, Arachnida). Zoomorphologie 94: 111–120.

Smrž J (1989) Internal anatomy of Hypochthonius rufulus (Acari: Oribatida). J Morphol 200: 215–230. PubMed

Krantz GW, Walter DE (2009) A Manual of Acarology. ed.3, Lubbock: Texas Tech University Press.

Castenholz RW (1992) Species usage, concept, and evolution in the cyanobacteria (blue-green algae). J Phycol 28: 737–745.

Taylor TN, Taylor EL (1993) The Biology and Evolution of Fossil Plants. New Jersey: Prentice Hall.

Allwood AC, Walter MRW, Kamber BS, Marshall CP, Burch IW (2006) Stromatolite reef from the Early Archaean era of Australia. Nature 441: 714–718. PubMed

Kalina T, Váňa J (2005) Cyanobacteria, algae, fungi, mosses and similar organisms in contemporary biology. Praha: Karolinum, Charles University Publ (in Czech).

Flechtner VR (1999) Enigmatic desert soil algae. In:.Seckbach J, Enigmatic microorganisms and life in extreme environments. Dordrecht: Kluwer Acad Publ. pp. 231–241.

Fay P (1965) Heterotrophy and Nitrogen Fixation in Chlorogloea fritschii . J Gen Microbiol 39: 11–20. PubMed

Mannan RM, Pankrasi HB (1993) Dark heterotrophic growth conditions result in an increase in the content of photosystem II units in the filamentous cyanobacterium Anabaena variabilis ATCC 29413. Plant Physiol 103: 971–977. PubMed PMC

Vinogradova ON, Kovalenko OV, Eviatar N, Weinstein-Evron M (2000) Cyanoprocaryotes/Cyanobacteria of Jamal Cave, Nahal Me'arot Nature Reserve, Mount Carmel, Israel. Algae 2: 41–50.

Nováková A, Elhottová D, Krištůfek V, Lukešová A, Hill P, et al... (2005) In: Tajovský K, Schlaghamerský J, Pižl, V, Contribution to Soil Zoology in Central Europe I. České Budějovice: ISB AS CR. pp.107–112.

Lamprinou V, Pantazidou A, Papadogiannaki G, Ladea C, Economouo-Amilli A (2009) Cyanobacteria and associated invertebrates in Leontari Cave, Attica (Greece). Fottea 9: 155–164.

Martínez A, Asencio AD (2010) Distribution of cyanobacteria at the Gelada Cave (Spain) by physical parameters. J Cave, Karst Studies 72: 11–20.

Abdullin Sh-R (2009) Cyanobacterial-algal cenoses of the Shulgan-Tash cave, southern Urals. Russ. J. Ecol. 40: 301–303.

Brinton LP, Burgdorfer W (1971) Fine structure of normal hemocytes in Dermacentor andersoni Stiles (Acari: Ixodidae). J Parasitol 57: 1110–1127. PubMed

Smrž J (2006) Types of haemocytes in saprophagous soil mites (Acari: Oribatida, Acaridida) and correlation between their presence and certain processes within mites. Eur J Entomol 103: 679–686.

Symonová R, Smrž J (2009) First Record of Hemocytes and Oenocytes in Freshwater Ostracodes. J Crust Biol 29: 18–25.

Vitzhum HG (1943) Acarina. In: Bronn's Klassen und Ordnungen des Tierreiches, Vol.5 , chap.3. Leipzig. pp.1–7.

Smrž J (2002) Nutritional biology: the basic step in the autecological studies (multi-methodical approach). Eur J Soil Biol 38: 35–38.

Smrž J, Materna J (2000) The dynamics of glycogen deposition within the parenchyma tissue of Melanozetes meridianus (Acari: Oribatida). Pedobiologia 44: 175–185.

Vandel A (1965) Biospeleology. The biology of cavernicolous animals. Oxford, London: Pergamon Press. 617 p.

Šustr V, Elhottová D, Krištůfek V, Lukešová A (2005) Ecophysiology of the cave isopod Mesoniscus graniger (Frivaldszky, 1865) (Crustacea: Isopoda). Eur J Soil Biol 41: 69–75.

The food web in a subterranean ecosystem is driven by intraguild predation