Identifying coral has been made easier thanks to researchers in Queensland who say their findings will help better manage climate-affected reefs across the world.
The study undertaken by James Cook University's Centre of Excellence for Coral Reef Studies examined the table corals of Okinawa, Japan, and how scientists had previously thought one species was a hybrid of another two.
Researchers described them as a "taxonomic nightmare" which led them to assessing whether similar looking species actually cross breed or hybridise.
What they found was the assumption of shape variations was due to hybridisation because coral species often spawn together, releasing eggs and sperm en masse.
Their alikeness is similar to those between mules and a horse and a donkey. Mules are a hybrid species of the two.
"The accurate identification of a species is the single most important aspect of all biology - in particular, for conservation and management," co-author Professor Andrew Baird said.
"The difference between coral species depends on a lot more than what they look like. Yet, that is traditionally how they've been classified, without considering how they breed, or their DNA."
Prof Baird went further, adding that the accurate identification of corals can be done "if you know your animals and use the correct tools".
These tools for species identification include molecular approaches - using DNA markers to reconstruct the genetic ancestry of an individual with others of the same species. However, even these present problems when identifying corals.
"The standard DNA markers that work for distinguishing species in other animal groups are frustratingly unhelpful for delineating coral species or reconstructing their evolutionary history," said Dr Peter Cowman, another co-author of the study.
The authors say the findings have implications for plans to rescue reefs from global warming by seeding affected reefs with heat-tolerant individuals from distant locations.
Australian Associated Press
Sign up for our newsletter to stay up to date.