We think that there’s a lot of corals in the global aquarium hobby but for all the SPS, soft corals, LPS, and various polyps we enjoy, these account for but a tiny fraction of corals out in the ocean. The corals we don’t know about, the Unseen Corals, represent a huge diversity of forms and lifestyles that can teach us more generally about the corals we are familiar with. Nanipora is a very unusual stony soft that is unlike almost any other coral that we know of, being related to the oddball blueridge coral, Heliopora coerulea, an eight-tentacles Octocoral that grows a unique kind of skeleton. Blue ridge coral is large, common and conspicuous on wild reefs but Nanipora takes a vastly different approach being a small cryptic encrusting species that is sometimes zooxanthellate, sometimes not.
We’ve very rarely seen Nanipora in the aquarium hobby, its low encrusting growth doesn’t exactly make for a showpiece in the aquarium and it’s similarly rare in the wild, preferring to grow in very hidden, interstitial areas such as under rocks, in between other corals, and places that other species don’t dare try and stake their claim. Although this cryptic oddball seems rather are, new paper by Reimer et. al. documents Nanipora kamurai has documented what appears to be an ideal habitat for the stony Octocoral.
On a volcanic reef with highly acidified waters due to seeps of carbon dioxide, researchers discovered an unusually high abundance of Nanipora among durable species like Porites, Sarcophyton, and mats of turf algae no doubt benefiting from the increased CO2. The soft and stony corals didn’t seem all that thrilled inside the lagoon where the high temperatures that almost scratched 90F or 32C as well as CO2 levels up to 1300 ppm but not only did the Nanipora appear unaffected, they weren’t found anywhere outside the lagoon!
Interestingly the surveys were initially conducted with typical linear transects wherein no colonies of Nanipora were found but once they switched to a more natural, roving method of inspection, they found numerous colonies and patches of Nanipora all over the place. The way these stony octocorals were discovered is a cautionary tale on how to find more unique and interesting corals on wild reefs, and more research is needed to better understand Nanipora’s apparent resilience in highly acidified seawater environments that are not unlike many aquariums.
