Ecological studies on tardigrades (Björndjur)

Tardigrades are small aquatic animals, often associated with mosses and lichens, and mainly known for their extraordinary ability to survive desiccation. The general biology and ecology of tardigrades are largely unknown, and important original contributions can therefore be obtained with relatively small efforts.

Several studies on semi-terrestrial tardigrades living on Ölands Alvar in South-Eastern Sweden have been done over the last decade. Especially one species in this area, Richtersius coronifer, has been the subject of many physiological and biochemical investigations. Still, there is a lack of basic knowledge on population patterns in this and other co-ocurring tardigrades at Ölands Alvar. There is therefore a need for general ecological studies on these populations. Several projects are possible and well suited for student examination projects:

1. How do tardigrade populations vary over the year? Using already collected material from Ölands Alvar, the yearly dynamics of tardigrade numbers and age-structure can be analysed. The study will include laboratory work with stereo and light microscopy.

2. Are there density-dependent factors acting in tardigrade populations? Given the very large variation in density of tardigrade populations, effects of density on, e.g. fecundity, can be analysed. The study will include both field collection and laboratory work with stereo and light microscopy.

3. How do moss-living tardigrades disperse? This question has received very little attention, but is important for understanding population patterns and dynamics. The study will include both field collection (possibly also experimental studies) and laboratory work with stereo and light microscopy.


The proposed student projects will take place in the only laboratory in Sweden with ongoing research on tardigrades.