Researchers have found a new way to distinguish and identify coral species\u2014providing crucial information to help manage coral reefs in a warming world.<\/p>\n
Co-author Professor Andrew Baird from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU) said there\u2019s more to identifying coral than meets the eye. He said the new results challenge a widely held assumption that many similar-looking species cross-breed, or hybridise.<\/p>\n
\u201cThe accurate identification of a species is the single most important aspect of all biology\u2014in particular, for conservation and management,\u201d Prof Baird said.<\/p>\n
\u201cThe difference between coral species depends on a lot more than what they look like. Yet, that is traditionally how they\u2019ve been classified, without considering how they breed, or their DNA.\u201d<\/p>\n
He said corals have spectacularly variable shapes and forms, which make them difficult to identify. But it can be done, \u201cif you know your animals and use the correct tools.\u201d<\/p>\n
Prof Baird said the assumption of shape variations being due to hybridisation emerged because many coral species often spawn together, releasing eggs and sperm en masse. And many colonies are intermediate in shape between one species and another\u2014in the same way that a mule is intermediate in shape between a horse and a donkey, as an actual hybrid species of the two.<\/p>\n
The modern tools for species identification include molecular approaches\u2014using DNA markers to reconstruct the genetic ancestry of an individual with others of the same species. However, even these present problems for corals.<\/p>\n
\u201cThe standard DNA markers that work for distinguishing species in other animal groups are frustratingly unhelpful for delineating coral species or reconstructing their evolutionary history,\u201d said Dr Peter Cowman, a co-author of the study from Coral CoE at JCU and Senior Curator of Biosystematics at the Queensland Museum.<\/p>\n
In the study<\/a>, the authors closely examined the table corals of Okinawa, Japan. These table corals are difficult to tell apart, a \u201ctaxonomic nightmare\u201d, and scientists had previously thought that one of these table species was a hybrid of the other two.<\/p>\n \u201cUsing novel genetic techniques, as well as breeding trials, we found they were all separate species that did not breed with each other,\u201d said the study\u2019s lead author Catalina Ram\u00edrez-Portilla, a PhD candidate from Universit\u00e9 libre de Bruxelles.<\/p>\n Coauthor Dr Jean-Francois Flot, also from Universit\u00e9 libre de Bruxelles, and the Interuniversity Institute of Bioinformatics in Brussels, says to date there are only a handful of confirmed cases of coral hybridisation in the wild.<\/p>\n \u201cMany intermediate forms, which were originally thought to be hybrids, are actually \u2018good species\u2019.\u201d Dr Jean-Francois Flot said.<\/p>\n \u201cThis also means that these species instead probably have a much more limited range of where they are found, with much smaller population sizes than previously thought,\u201d he said. \u201cWhich makes them far more vulnerable to threats, and they should have a far greater conservation status.\u201d<\/p>\n Dr Saki Harii from Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus said, \u201cShallow corals around Sesoko Island have been studied for decades by researchers from all over the world. Solving species identity issues is crucial to allow for reliable comparisons among these studies.\u201d<\/p>\n The authors say the findings have important implications for current plans to rescue reefs from global warming by seeding affected reefs with heat-tolerant individuals from distant locations.<\/p>\n \u201cIt is absolutely critical to use and compare data from the correct species before we move them around or attempt to manipulate their genetics,\u201d they said.<\/p>\n \u201cMore basic biology is the key to effective conservation and management rather than blue sky projects that are unlikely to work and come with substantial risks.\u201d<\/p>\n \u2013ENDS\u2013<\/em><\/strong><\/p>\n <\/p>\n PAPER<\/strong><\/p>\n Ram\u00edrez-Portilla C, Baird A, Cowman P, Quattrini A, Harii S, Sinniger F, Flot J. (2021). \u2018Solving the Coral Species Delimitation Conundrum\u2019. Systematic Biology<\/em>. DOI: 10.1093\/sysbio\/syab077<\/a><\/p>\n IMAGES<\/strong><\/p>\n A selection of images<\/a> can be used for media stories with credit to the photographer as stated in the image caption. Please note these are for single use with this story only, not for any other story. No archival permissions are granted.<\/p>\n CONTACTS<\/strong><\/p>\n Andrew Baird<\/strong> (Townsville, AEST) Peter Cowman<\/strong> (Townsville, AEST) Catalina Ram\u00edrez-Portilla<\/strong> (Colombia) Jean-Francois Flot<\/strong> (Belgium) Saki Harii<\/strong> (Japan)
\nP: +61 (0)400 289 770
\nE: andrew.baird@jcu.edu.au<\/a><\/p>\n
\nP: +61 (0)490 231 223
\nE: peter.cowman@qm.qld.gov.au<\/a><\/p>\n
\nE: catalina.rzpl@gmail.com<\/a><\/p>\n
\nE: jflot@ulb.ac.be<\/a><\/p>\n
\nE: sharii@lab.u-ryukyu.ac.jp<\/a><\/p>\n