7. Sea Creatures and Their Protector Microbes
Predators are a danger to many animals, so they have developed ways to keep themselves safe.
The Hawaiian bobtail squid hunt for food at night to hide from predators. They turn on colourful lights inside their bodies to attract prey and to prevent shadows appearing underneath them. The light is provided by bacteria Vibrio fischeri inside their body that lives happily there causing no harm!
Check out the first minute of this video where microbiologist Dr Siouxsie Wiles, an Associate Professor and head of the Bioluminescent Superbugs Lab at the University of Auckland, New Zealand (she did her degree at the University of Edinburgh!), explains how the light that the Hawaiian bobtail squid makes camouflages them:
The blue-ringed octopus lives deep in the sea. They can protect themselves from the prey by first poisoning and then eating it. But they cannot make the toxic substance on their own… they need bacteria called Vibrio to make the toxin, which lives in their saliva.
The blue-ringed octopus sends out a warning signal to tell predators that it is poisonous. Check out this video of a blue-lined octopus, a member of the blue-ringed octopus group, to see what this signal is:
These are examples of a symbiotic relationship – where the microbe lives together with the other species. In these cases, one species (the leaf-cutter ant, the squid or the octopus) benefits from the other (the microbe) but no harm is caused to either of them. Not every symbiotic relationship is helpful.
In our final fact, we return to lichens, which you hunted for earlier this week, they are another example of a symbiotic relationship.
The origin of plants is thanks to microbes
Watch this video which features Chris, one of our microbiologists, as he explains why plants are green!
Chris Earl was born in Dundee and completed a Molecular Biology degree and a Ph.D. in Microbiology both at the University of Dundee. Still based here, Chris is now investigating how some species of bacteria can inject toxins into other bacteria to kill them. The benefit of this, is that by removing competitors from the environment the bacteria now no longer compete for the same scarce, vital nutrients. These toxins may one day be used by humans as antibiotics to kill harmful bacteria which cause human disease.
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