At John Brewer Reef, off Townsville, some corals that looked like familiar species have turned out to be something else: distinct species that science had set aside for generations. A new study has brought 12 of these overlooked corals back into view on Australia's east coast, including the Great Barrier Reef.
The research matters because knowing exactly which species live on a reef helps scientists understand its biodiversity and decide what needs protection. Acropora, the group studied, includes branching staghorn corals and broad, table-shaped corals. For decades, experts have struggled to tell whether differences in coral shape mark separate species or simply reflect how one species grows in different conditions.
Led by Dr. Augustine Crosbie of James Cook University and Queensland Museum, an international team combined modern DNA analysis with old museum specimens. The work was carried out with Queensland Museum's CoralBank project and published in the journal Invertebrate Systematics. Researchers reassessed 53 named Acropora species, including 40 first described from Australia's east coast.
The team found evidence that 47 of the species were distinct. Twelve that had been treated as synonyms—names considered to refer to the same species—were recognized again as separate species. Four other species, whose status had been uncertain, were also accepted as valid. The results do not mean all 53 names were confirmed as distinct; rather, the study clarified which names the evidence supported.
Museum collections were central to the work. Many of the original specimens are preserved coral skeletons that cannot be sequenced directly. So the researchers collected living corals from the places where the species were first described, then connected those modern samples and their genomic data to the historic collections. That allowed the team to compare today's corals with the specimens on which the original names were based.
Crosbie said many of the corals had been known to science for more than a century, but had been mistaken for forms of other species. Queensland Museum CEO Renai Grace said the project showed how collections built through decades of careful work can still advance scientific knowledge. The specimens helped researchers revisit old classifications with new tools, rather than leaving historical records behind.
The change in names can also change how scientists see a species' risks. Peter Cowman, a Queensland Museum principal scientist and James Cook University associate professor, said a coral thought to be common across a wide area may actually be several species, each with a smaller range. That distinction matters when assessing extinction risk, tracking reef communities and deciding where conservation effort is most useful.
The findings are a reminder that even the Great Barrier Reef, among the most studied ecosystems on Earth, still holds details scientists have yet to fully understand. As researchers continue linking museum records with modern genetic evidence, clearer species identities can give reef monitoring and conservation a stronger foundation.