Sydney - Without their distinctive livery, lots of little reef fish would look much the same. Colour differentiates them, not shape.
The blue-striped fangblenny, found in coral reefs in Indonesia and Australia, is different. What marks it out from every other fish known to man is that it can change colour at will.
The default colour is brown, but the fangblenny can switch to yellow or a range of other bright hues to deceive other fish.
"Their repertoire of disguises appears to prevent or reduce detection by potential victims," says Queensland University marine biologist Karen Cheney. "They may also escape from predators by hiding in a large shoal."