A comparative study on inorganic ions i five different species of Tardigrada

Kristine Wulff Larsen

Studenteropgave: Speciale


Tardigrades are a minute aquatic or limno-terrestrial animals that have been found worldwide, inhabiting some of the most diverse and fluctuation ecosystems in the world. Their ability to survive extremities, including severe desiccation, has giving them a lot of attention. However the mechanisms explaining the extreme adaptation found among tardigrades is still not elucidated. In this master thesis we will present data on the inorganic ion composition and total osmotic concentration of five different species of tardigrades (E. testudo, M. tardigradum, R. coronifer, M. cf. hufelandi and H. crispae) by using high performance anion-exchange chromatography as well as nanoliter osmometry. The detection of ions showed that the principle inorganic ions in tardigrade fluids are Na+ and Cl-, albeit substantial concentrations of K+, NH4-, Ca2+, Mg2+, F-, SO42- and PO43- also were detected. In two species (M. tardigradum and H. crispae) an anion deficit of ~120 mEq/l was detected, which indicate that there are ionic components that remain unidentified. When comparing the total osmotic concentration in all species with the osmotic concentration of their surrounding media, we can deduce that both the limno-terrestrial and marine species hyper-regulate. Concentrations of most inorganic ions are largely identical between active and dehydrated specimens of R. coronifer, suggesting that this species does not exclude large amounts of ion during dehydration. In addition, our data indicates that cryptobiotic tardigrades contain a large fraction of unidentified organic osmolytes.

UddannelserMiljøbiologi, (Bachelor/kandidatuddannelse) Kandidat
Udgivelsesdato4 jul. 2012
VejledereHans Ramløv


  • Tardigrades
  • inorganic ion
  • Physiology
  • HPLC