By Victoria Gill
Science reporter, BBC News, Portland
Red Sea coral reefs get their complex shape from an ancient 'seabed template', say scientists.
Their distinctive appearance can be seen clearly in satellite images of the region and has its origin in seabed erosion thousands of years ago.
The scientists say the corals have simply adopted and accentuated the pattern created in once-exposed rock moulded by heavy rains.
They presented the findings at the Ocean Sciences meeting in Portland, US.
Dr Sam Purkis from the National Coral Reef Institute in Florida, US, led the research.
He explained that, in most cases, reefs did not form on a template.
"They are their own template," he said. "Corals simply settle on other corals and the reef forms in the ideal shape to suit the ecosystem.
"In the Red Sea it seems, for the most part, to be rather different."[read more]