Aquila Children's Magazine aquila-mathsInNature-0517 | Page 7

scientists set out oats in a pattern that matched the cities and towns around Tokyo, then they set their slime mould loose on it. In just a day the slime had found all the oat flakes and connected them with a network of veins. When they compared the network to a map of the railway lines around Tokyo, they found the slime matched them almost perfectly – and where it didn’t, the slime mould had found a much better route. Not bad for a bag of yellow goo! Who are you calling goo? LIFE CYCLE Slime moulds have an unusual life cycle. They hatch from spores into a microscopic cell that looks just like an amoeba. These amoebae swim around feeding off bacteria, and reproduce by dividing. When two of them meet they can join together and become the adult giant cell (plasmodium). When the plasmodium is big enough it grows tiny mushroom-shaped bits packed with spores, these burst open and the spores are spread by the wind to new areas for the slime mould to colonise. SLIME MOULDS IN THE WORLD There are around 1,000 species of slime mould found all over the world, most live on damp ground under trees and moss, and climb upwards on tree trunks and branches when they want to make spores. A few species live underwater and there are even a few that live in snow in the Arctic. The species that most scientists keep is the bright yellow Physarum polycephalum; it’s quite happy living on a bit of blotting paper and being fed on oats. If Physarum runs short of water it can dry out into a dormant lump called a sclerotium that can wait for years before being revived – very handy for scientists wanting to post a bit to friends or go on holiday for a couple of weeks! 1 2 A FUSSY EATER? When a slime mould was given a choice of oats covered in paprika, black pepper, chilli pepper or turmeric, the mould chose the paprika and stayed well away from the other choices on the menu! This showed that slime moulds have the ability of chemotaxis – meaning they are attracted to, or repelled by, different chemicals they sense in their environment. Who knew a slime mould could have such a sensitive palate?! FUN FACT TRUMPET In some areas of South America, people gather up slime moulds and cook them like scrambled eggs! 3 Thanks to Ian Hands-Portman from the University of Warwick for sharing all his slime mould knowledge with us and even sending us some in the post. I wonder, if Ian had left a trail of oats from Warwick to Eastbourne, would Slimy McMouldypants have made his own way here? 4 7