The brine shrimp artemia: adapted to critical life conditions.

The brine shrimp Artemia is a micro-crustacean, well adapted to the harsh conditions that severely hypersaline environments impose on survival and reproduction. Adaptation to these conditions has taken place at different functional levels or domains, from the individual (molecular-cellular-physiological) to the population level. Such conditions are experienced by very few equivalent macro-planktonic organisms; thus, Artemia can be considered a model animal extremophile offering a unique suite of adaptations that are the focus of this review.

The New World Artemia species A. franciscana and A. persimilis are highly differentiated for chromosome size and heterochromatin content.

Chromosomal rearrangements have played a key role in the speciation of the New World sexual Artemia species (Crustacea, Anostraca) A. franciscana and A. persimilis.

Inland hypersaline lakes and the brine shrimp Artemia as simple models for biodiversity analysis at the population level.

Biodiversity can be measured at different hierarchical levels, from genetic diversity within species to diversity of ecosystems, though policy-makers tend to use species richness. The 2010 goal of reducing biodiversity loss, agreed by the subscribers to the Convention on Biological Diversity, requires simple and reliable protocols to evaluate biodiversity at any level in a given ecosystem. Stakeholders, particularly policy makers, need to understand how ecosystem components interact to produce social and economic benefits on the long run, whilst scientists are expected to fulfil this demand by testing and modelling ideally simple (low diversity) ecosystems, and by monitoring key species.