SPONGES in the chilly waters of Antarctica are infested with algae that scrounge off them during the dark polar winter.
Algae often live inside the cells of other animals, such as reef-building corals, but they usually provide some benefit in return for their lodging. The diatoms found in Antarctic sponges by Giorgio Bavestrello of the University of Ancona and his colleagues are the first known algal parasites (
The researchers think this parasitic behaviour allows the algae to survive the long Antarctic winters, when it is too dark to photosynthesise.
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