Smelly Coral Fish Dodge The Predators
We've all heard of animals using colour to blend in with their environment and avoid predators. Well, they can also use smell - or lack of it - as camouflage.
Previous research has found that fish can make themselves "chemically invisible" to predators by reducing the odour they give off.
Now, Brooker and colleagues have found they can also blend in by making themselves smell like their environment.
"It's the very first time it's been shown," says Brooker.
In research carried out for his PhD at James Cook University in Townsville, Brooker studied the coral-feeding filefish Oxymonacanthus longirostris.
The 8-centimetre long filefish lives on coral (mainly Acropora coral), in the Indo Pacific region including the Great Barrier Reef. It both eats the coral and relies on it for shelter.
The researchers put the two species of crab in the tank with the fish - without the crabs actually being able to see the fish.
"The fish were hidden and the only thing the crab was getting was the smell of the two fish and then we watched where the crab went," says Brooker.
They found the crabs went towards the fish that had been feeding on the coral type the crabs normally live on.
"The crabs that live on Acropora went to the fish that had been feeding on Acropora and the crabs that live on Pocillopora went to the fish that had been feeding on Pocillopora," says Brooker.
http://www.abc.net.au/science/articles/2014/12/10/4145224.htm
Wonder what they do to get rid o crabs ay! 
