Parasites as Part of the Antarctic Biodiversity

BARBOSA, A.; VIDAL, V.; ORTIZ, J.; DIAZ, J. I.; DOLNIK, O

Liege

Workshop; Antarctic Biodiversity Workshop; 2011

Parasitism is the most common lifestyle on the planet. Almost every individual is infested by parasites at any time during its life cycle. Recent estimates suggest that parasites are a 50% more numerous than the free-living species. Moreover, the influence of parasites on the diversity of ecosystems through their effects on the hosts has been recently emphasized. Parasites may regulate host population size, demographic structure, drive host population cycles, affect host behaviour, determine host genetic structure, promote the evolution of secondary sexual characters and in general they are driven the variability of the immune system in the hosts. However is not usual that parasites are considered as part of the biodiversity and most studies dealing with this aspect neglect its importance in this topic. Information about parasites in Antarctic fauna is scarce and fragmented in comparison with other ecosystems. Moreover, the information about the presence or the effects of parasites in Antarctica in some cases is very old. Therefore, a part of the Antarctic biodiversity information is not being considered. An extreme example is the consideration of ticks (Ixodes uriae) as a component of the Antarctic biodiversity. Until very recently ticks were known to be distributed in some penguin colonies at Palmer archipelago, however a careful survey along the Antarctic peninsula has shown that ticks are more abundant than it was thought. As an example of Antarctic parasite biodiversity I will present data on the parasites present in Antarctic seabirds with special attention on penguins.