DEEPHOPE in Zootaxa (2024)

Black corals are ecosystem engineers, found at all latitudes around the globe and at all depths. When they occur at high densities, they form what are known as marine animal forests. Some of these forests have already been studied, particularly in the mesophotic zone (30–150 m depth) in Hawai’i, the Canary Islands, or the Mediterranean, but other regions remain poorly explored.

This is the case for the mesophotic coral ecosystems of Mo’orea (French Polynesia), which the authors focused on in the present article. Divers from Under The Pole collected 64 specimens of black corals between 60 and 120 m depth, which the authors then attempted to identify.

By combining morphological and genetic analyses, the authors described a new species: Stichopathes desaturata, adding to the roughly three hundred black coral species already known! They chose this name (derived from the Latin saturo, meaning “saturated”) in reference to the long decompression stops required by these technical dives after collecting specimens at 120 meters depth.

Photo of the newly described species, Stichopathes desaturata, from the article (figure 3).

The authors thus described the holotype of this new species—that is, the specimen that will now serve as the global reference for this species. It is preserved at the Museum of Natural History and Vivarium of Tournai (Belgium).

Furthermore, this study confirms the findings of numerous articles showing that black corals are opportunistically associated with dinoflagellates (unicellular algae), unlike hard corals (scleractinians), for which this association is essential.

However, some collected specimens could not be identified. Indeed, the classification of black corals and the identification of specimens remain significant challenges due to the variability of morphological traits, even within a single species. It has already been shown that the morphology of black corals belonging to the same species can vary depending on environmental conditions (current, substrate angle, etc.) to the point where identification becomes uncertain. The classification of black corals of the genus Stichopathes and the number of described species may therefore still evolve.

Summary from the article "Whip black corals (Antipatharia: Antipathidae: Stichopathes) of the Mesophotic Coral Ecosystem of Mo’orea (French Polynesia), with the description of a new species."

Read the full article via the link below. 

Authors - Terrana L, Rouzé H, Opresko D, Under The Pole consortium, Eeckhaut I, Dubois P, Hédouin L, Godefroid M.