ALO docView - Redescription and notes on the biology of the glacier tardigrade Hypsibius klebelsbergi MIHELCICI, 1959 (Tardigrada), based on material from the Ötztal Alps, Austria (2003)

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Redescription and notes on the biology of th... (2003)

	Mitt. hamb. zool. Mus. Inst. Band 100 S.73-100 Hamburg, November 2003 ISSN 0072 9612 Redescription and notes on the biology of the glacier tardigrade Hypsibius £/ebe/sberg/'MmELClC, 1959 (Tardigrada), based on material from the Ötztal Alps, Austria Hieron ymus Dastych 1 , Hans Jörg Kraus 2 & Konrad Thaler 3 1 Universität Hamburg, Zoologisches Institut und Zoologisches Museum, Martin-Luther-King- Platz 3, 20146 Hamburg, Germany; 2 Schloss-Tratzberg-Straße 40, A-6200 Jenbach, Austria; 3 Institut für Zoologie & Limnologie, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria. ABSTRACT. - A redescription of a cryobiotic tardigrade, Hypsibius klebelsbergi MlHELClC, 1959, is presented, based on material from cryoconite holes on the glacier Rotmoosferner in the Ötztal Alps (Austria). Much of the basic morphometric data of H. klebelsbergi is provided here for the first time and the bulk of available biological and ecological information about the species and its distribution is evaluated and discussed. The combination of some characters of H. klebelsbergi (e.g., the shape of anterior apophyses of the mouth tube and of the claws) indicates its separate generic Status. A bisexual (amphimictic) reproduction mode for H. klebelsbergi is implied. The latter and the taxonomic position of the species, including its possible synonymy with H. janetscheki Ramazzotti, 1968, known only from a Himalayan glacier, require further studies. KEYWORDS: Tardigrada, Hypsibius klebelsbergi, redescription, SEM, taxonomy, glaciers, cryo¬ conite holes, cryobiont, ecology, the Alps, Austria. Introduction Only a few invertebrate taxa dwell permanently on glaciers, where all available habitats are characterized by harsh environmental conditions. Cryoconite holes (= Kryokonitlöcher, Mittagslöcher), are aquatic microcaverns that occur on the ice surface (Fig. 1) in the glaciers' ablation zone. These holes are caused by dark particles of fine dark inorganic and organic debris warmed by solar radiation and sinking into the ice surface (black body effect). The term for the mainly wind transported debris, cryoconite or "ice dust" {kryos = ice, konis = dust, Gr.), was introduced by NORDENSKJÖLD in 1870 (see STEINBOCK 1936). Cryoconite holes occur in polar regions and mountain glaciers world- wide and play an important role in the acceleration of the deglaciation processes (e.g., TAKEUCHI et al. 2001). Still, little is known about physical conditions and chemical components of cryoconite holes and even less about their flora and fauna. Some charac- teristics of cryoconite holes, including partly their biota, have been provided by, e.g., Steinbock 1936, 1957, An der Lan 1963, Mihelcic 1963, Kraus 1977, De Smet & Van Rompu 1994, GR0NGAARD et al. 1999, Takeuchi et al. 2001, Säwström et al. 2002.