Author: Andrew Baird

The team at Project Phoenix has just published a paper in the Zoological Journal of the Linnean Society titled “A tenuis relationship: traditional taxonomy obscures systematics and biogeography of the ‘Acropora tenuis’ (Scleractinia: Acroporidae) species complex.” 

The paper is open access and available here.

In the words of one of the reviewers,

“This is an important paper on a controversial topic. It is revolutionary in many ways and should appeal to a broad readership. It sets the stage for a more comprehensive revision of Acropora, which agrees with molecular data.”

The paper demonstrates that the putatively widespread species ‘A. tenuis’ is actually numerous distinct species with much smaller geographical ranges. Taxonomic actions in the paper include:

• The resurrection of four nominal species considered junior synonyms of A. tenuis
  • Acropora macrostoma (Brook, 1891) with a type location in Mauritius
  • Acropora kenti (Brook, 1892) with a type location on the norther Great Barrier Reef
  • Acropora bifaria (Brook, 1892) with a type location in Java
  • Acropora africana (Brook, 1893) with a type location in South Africa
• The resurrection of A. akajimensis Veron, 1990, with a type location in Okinawa, Japan, previously considered a junior synonym of A. donei Veron & Wallace, 1984, type location on the GBR.

The paper also describes two new species:

• Acropora tenuissima Bonito, Bridge, Fenner & Baird, 2023 (Fig. 1 below)
• Acropora rongoi Bridge & Cowman, 2023

In addition, the paper suggests that at least some of ‘morphological species groups’ of Wallace (1999) are not monophyletic because the morphological characters on which they are based appear in multiple different clades, suggesting these characters have evolved independently.

The restricted range of the true Acropora tenuis means that all research that has claimed to work on this species – except work done in Fiji – used a different species. A search for “Acropora AND tenuis” on Web of Science on 04/08/2023 returned 218 results and none of these results included “Fiji”. So that’s 218 papers that got their coral taxonomy wrong – 8 of which are mine! Similar results are to be expected for other Acropora “lab rats” e.g. A. millepora (500), A. hyacinthus (184), A. nasuta (37) and A. valida (50); number in parentheses indicate search result counts. Clearly, the current taxonomic framework for the genus Acropora is broken. Most importantly, caution must be exercised when comparing results among studies that claim to be working on the same Acropora species, particularly if they come from different parts of the world for example, Japan vs Australia.