Under construction! (2012-ACAN003)
Dying Acanthastrea Coral Rehabilitation
Acanthastrea
Dying Acanthastrea Coral Rehabilitation
This coral is still with me, which is over 11 years since I rescued it. During that time, it has had quite the identity crisis. When I first rescued it, I wrote on an old blog, “Many large polyp stony corals are difficult, if not impossible, to identify without examination of a coral’s skeleton. Thankfully, the genus Trachyphyllia is not, as it only has one species: geoffroyi.” HAHAHA, oh how much we have learned since then! So, not only did this dying Acanthastrea coral go through an amazing rehabilitation, but it also fell into a few different genera along the way.
Assessing Dying Coral Health:
When I found this coral at a Local Fish Store (LFS) in November, 2010, I believed it was a Trachyphyllia geoffroyi, mostly due to its hourglass shape (and lack of good reference material on coral septa patterns at the time).
Although it is pure speculation, I believed the coral’s condition was due to rapidly deteriorating water conditions. The freshly exposed skeleton showing bright in white suggested something drastic changed, and the fairly uniform amount of exposed skeleton suggested the source of the problem surrounded the coral. The good coloration (albeit slightly bleached) indicated that lighting and some infections were not likely. But, the tight skin against the skeleton along with the gaping mouths suggested the coral was probably not eating and possibly acting defensively to reduce its exposure to poor water quality. (For more information, see Assessing Coral Health: An Introduction.)
Quarantined Acanthastrea Coral:
Poor water conditions could have meant allelopathy (chemical warfare between corals), high nitrates/ phosphates, unbalanced alkalinity/ calcium/ magnesium, et cetera. To treat this coral I purchased for $10, I decided the best course of action was just a good aquarium. After completing my coral examination and dip, I cut the coral’s septa (the teethy-ridges). I have found that if a large polyp coral was to suddenly inflate in excessive flow, the flesh will easily rip on the septa. With a sick coral, one small tissue tear can continue to rip or become infected and quickly lead to the demise of the coral. To prevent this, I carefully trimmed back the septa and removed all sharp points. The coral could then expand with little difficulty. Additionally, corals seem to have more ease in growing back over the existing skeleton this way.
Acanthastrea Coral in Grow-out:
Only a few weeks later (21 November 2011), the coral was inflating and starting to grow over the exposed skeleton.
I regularly fed it pellet food, as highly processed food seems to be easier to digest for injured corals. Notice the orange ring developing! (30 January 2011)
The progression in only a couple weeks was rapid. The coral nearly covered all previously exposed skeleton, by only 24 February 2011 (about four months after I purchased it). However, by this point, I was starting to question my initial assessment of Trachyphyllia geoffroyi. It was starting to look more like a Lobophyllia, but it was still more hourglass-shaped.
Previously Dying Acanthastrea Coral, Fully Rehabilitated:
By October 2011, I realized I was probably wrong about the genus. It was splitting more like a Lobophyllia. But at that point, I really didn’t care, as the coral was fully healed (less than a year later!)
Not just Surviving, but Thriving!
Although this coral’s recovery was impressive under daylight conditions, under actinics it became a showstopper!
Around 2016, several studies and articles starting making me rethink the classification on this coral. Rather than Lobophyllia pachysepta, it seemed to fit more within Acanthastrea (Huang, et al., 2016).
Here’s the previously dying Acanthastrea colony in 2021, which was still large despite a few fraggings over the years!
Conclusion:
From nearly dead to thriving in less than a year… to over 11 years later… this coral continues to awe and confuse me! This dying Acanthastrea coral’s rehabilitation also went from Trachyphyllia geoffroyi to Lobophyllia pachysepta to Acanthastrea pachysepta, or at least so I think!
References
- Huang, Danwei, Roberto Arrigoni, Francesca Benzoni, et al., “Taxonomic Classification of the Reef Coral Family Lobophylliidae (Cnidaria: Anthozoa: Scleractinia), Zoological Journal of the Linnean Society, 2016, 178, 436-481.
- Arrigoni, Roberto, Francesca Benzoni, Danwei Huang, et al., “When Forms Meet Genes: Revision of the Scleractinian Genera Micromussa and Homophyllia (Lobophylliidae) with a Description of Two New Species and One New Genus”. Contributions to Zoology 85.4 (2016): 387-422.
Dying Acanthastrea Coral Rehabilitation
Assessing the Coral’s Health:
This dying Acanthastrea (“Acan”) coral came out of a hobbyist’s tank that had been neglected due to an impending move. Notice the lack of tissue between the polyps. Luckily, corals in poor water conditions usually recover quickly in a mature, well-maintained aquarium. Rehabilitation should be easy with just proper, basic care. (Photo taken 9 June 2012)
Preparation for Quarantine:
Since the coral just needed a healthy environment, there wasn’t a whole lot I could do. There was some nuisance algae on it, so I cut those sections off. I gave the coral a dip in Coral Rx to check for pests just in case. Within less than a month, the polyps were already expanding out more and growing larger. (Photo taken 30 June 2012)
Quarantined Coral:
Within a month, the previously dying Acanthastrea coral looked almost like it had never had a problem. Unfortunately the remaining skeleton kept growing nuisance algae, so I kept having to remove it to facilitate its rehabilitation (white areas in the photo, taken 7 July 2012.)
Coral Grow-Out:
After a month in quarantine, I was able to re-dip the coral and place it into a grow-out tank. In a grow-out tank, I can continue to monitor the coral for any remaining issues while not exposing it to other incoming quarantined corals.
Within only two months the polyps were fully expanding and growing tissue between them (14 August 2012). Around this time I purchased a band saw, so I cut off the part of the disc that kept growing nuisance algae.
Rehabilitated Acanthastrea Coral:
Not too shabby! All this coral needed was a bit of TLC and some good water to make a full recovery within six months. (7 October 2012)
I had this coral for several years, during which time I fragged it many times to pass along to other hobbyists. For all I know, I may still have some of it, but I’ve lost track of which Acan coral it may be in my tank after a few moves and having several similar corals (what a great problem to have!)
