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16 | NewScientist | 25 August 2012 APHIDS may recharge their batteries as they sit in the sun. A handful of animals live in symbiosis with photosynthetic microbes, but none have been found that harness light directly. Now there are hints that aphids increase their production of ATP – the biological energy molecule – in response to light. While this doesn’t prove they photosynthesise, it is an intriguing hint that they might. Carotenoids are common in algae and some bacteria and fungi, where they harvest light for photosynthesis. Aphids are the only insects known to have the genes to produce carotenoids; the molecules give them their colour. Maria Capovilla of the University of Nice in France and colleagues found that light boosted ATP production in aphids Joe Public’s role in protecting species CITIZEN science is alive and well. Species nominated for protection by members of the US public are as worthy of protection as those identified by the US Fish and Wildlife Service (FWS). The US Endangered Species Act of 1973 gives citizens, as well as the government, a role in selecting species for protection. But critics say that citizens are politically motivated, using the act to block developments like new shopping malls rather than to protect vulnerable species. Berry Brosi at Emory University in Atlanta, Georgia, and colleagues have now compared the species selected by the public with those protected by FWS recommendations. They found that species chosen by citizens faced significantly higher levels of biological threat than those chosen by the FWS, suggesting that citizens play a valuable role in the process (Science, doi.org/h6h). The killer with a powerful ability to imitate THE killer whale has a ferocious appetite for imitation. It is as quick as a dolphin when it comes to picking up a new trick from one of its peers. Killer whales (Orcinus orca) are smart predators. Those in Patagonia have learned to climb onto beaches to catch sea lions, while the whales around the Antarctic Peninsula create waves to knock seals off ice floes. These different styles of hunting may be cultural: learned behaviours that are shared by members of discrete killer whale populations. José Abramson of the Complutense University of DOUG ALLAN/NATUREPL.COM IN BRIEF Can some insects photosynthesise? that have carotenoids, but not in lines bred to lack them (Scientific Reports, doi.org/h6k). Capovilla says this suggests the aphids may have the elements of a photosynthesis-like mechanism. Christopher Howe of the University of Cambridge points out that the experiment does not prove the existence of such a mechanism. Rather than driving the reaction, light could be playing an as-yet-unknown and indirect role in the production of ATP. Madrid, Spain, and colleagues studied three killer whales living in an aquarium in Antibes, France. In tests, using a previously learned “do that” command, the researchers instructed one of the whales to imitate an action that another was performing. Each whale imitated 15 behaviours that they already knew, such as slapping the water with their fins, and four that they had never seen or attempted before, including barrel rolls. The whales took no more than eight attempts to successfully imitate a familiar behaviour, and even the new behaviours took no more than 16 tries to perfect. That puts them on a par with captive dolphins, says Abramson. Wild cetaceans lack a history of training and so might take longer to learn similar skills (Animal Cognition, doi.org/h6j). CHEW over this evolutionary story. Rodents, which account for nearly 40 per cent of living mammal species, owe much of their success to their teeth – yet one rodent has got rid of most of its gnashers. Paucidentomys vermidax was discovered in Indonesia last year by Jacob Esselstyn of McMaster University in Hamilton, Ontario, Canada, and his colleagues. It has no molars, and its incisors are shaped for gripping food rather than gnawing (Biology Letters, DOI: 10.1098/rsbl.2012.0574). Esselstyn found that the rodent’s stomach was packed with the remains of earthworms. He thinks it might live entirely on soft-bodied animals, which would explain why it would not need so many teeth. How the rodent lost its teeth
