CAnMove

A common response to threat is to move or migrate away from it. Such movements of small organisms (1-3 mm) is not so easily tracked since the tracking devices available are too heavy to allow the organism to act naturally. The rapid development of nanoscience offers opportunities for studies in small scale biology since nanosized (109m) objects can be carried by small (mm-scale) organisms without affecting their behaviour.
 
As model organisms for testing nanoparticles as tracking device we initially use two taxa of crustacean zooplankton, copepods and cladocerans (genera: Daphnia). These are common, often co-occurring zooplankton with a size of generally about 1-2 mm.  Daphnia is parthenogenetic, i.e. has a short generation time, and performs strong diel migration in response to UV and predation, whereas their photoprotective pigmentation is low. Copepods, on the other hand, has a completely different strategy with strong, and plastic, photoprotective pigmentation, but weak diel migration. The animals are easy to maintain in the laboratory, show strong plasticity and use chemical cues from e.g. predators, making them very suitable as model organisms.
 
The nanoparticles are firmly attached to the surface of the animals by chemical binding and our preliminary methodological tests show that the animals are unaffected by this procedure and behave, reproduce and survive normally. Hence, we have hitherto not seen any effect on the animals due the marking which, according to pilot studies, allows us to study behavior and decisions of individual animals irrespective of surrounding light conditions. This has never been possible before and compared to previous methods these, very preliminary, results are extremely promising!