SIMPLE animals such as insects, worms and crustaceans may have more complicated immune systems than we thought. Water flea babies have been found to inherit immunity to bacteria from their mothers, suggesting that biologists may have to abandon the idea that invertebrates do not have advanced immune systems that “remember” pathogens.
Tom Little and his team at the University of Edinburgh infected female water fleas (Daphnia magna) with a strain of the bacterium Pasteuria ramosa. They then challenged the fleas’ offspring with either the same strain or a different one. Fewer babies became infected when exposed to the same pathogen…
