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Volume and morphology changes of a bdelloid rotifer species ( Macrotrachela quadricornifera ) during anhydrobiosis
Author(s) -
Ricci Claudia,
Caprioli Manuela,
Fontaneto Diego,
Melone Giulio
Publication year - 2008
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.10579
Subject(s) - cryptobiosis , biology , rotifer , desiccation , confocal laser scanning microscopy , morphology (biology) , volume (thermodynamics) , tardigrade , body cavity , anatomy , biophysics , zoology , ecology , physics , quantum mechanics
Abstract Following a study on the changes occurring in a bdelloid species ( Macrotrachela quadricornifera , Rotifera, Bdelloidea) when entering anhydrobiosis, we investigated the changes in morphology, including weight and volume during the transition from the active hydrated to the dormant anhydrobiotic state by scanning electron microscopy, confocal microscopy and light microscopy. We compared sizes and morphologies of hydrated extended, hydrated contracted and anhydrobiotic specimens. Bdelloid musculature is defined: longitudinal muscles are contracted in the hydrated contracted animal (head and foot are retracted inside the trunk), but appear loose in the anhydrobiotic animal. When anhydrobiotic, M. quadricornifera appears much smaller in size, with a volume reduction of about 60% of the hydrated volume, and its internal organization undergoes remarkable modifications. Internal body cavities, clearly distinguishable in the hydrated extended and contracted specimens, are no longer visible in the anhydrobiotic specimen. Concomitantly, M. quadricornifera loses more than 95% of its weight when anhydrobiotic; this is more than expected from the volume reduction data and could indicate the presence of space‐filling molecular species in the dehydrated animal. We estimate that the majority of body mass loss and volume reduction can be ascribed to the water loss from the body cavity during desiccation. J. Morphol., 2008. © 2007 Wiley‐Liss, Inc.