Cynarina splitting in two!

[TALI]

I had the coolest thing happen in my reef aquarium!!! Last Thanksgiving, my beautiful Cynarina coral peeled himself off his skeleton. I had no idea why, he didn't seem stressed at all. My tank parameters were all good. So I put him in a floating fish hatchery, and he's been chillin' in there happily since. He had himself in a twist for the last couple of weeks, and tonight I noticed that he has split himself into two little button corals! This process took since thanksgiving, and I can't find anything about large polyp stony corals like this reproducing by splitting. In some reef forums I'm being told it's polyp bailout, but he's reproduced that way. Anybody have any experience with this? Will they ever regrow their skeletons?

 

[BlueNem]

Following

 

[thamnasteroid]

polyp bailout; unlikely to survive

 

[TALI]

I've been reading articles that have been posted, and I found this;

It is striking that some mechanisms of asexual reproduction resemble those of polyp bailout. For example, processes similar to polyp bailout, in which polyps are ejected from corallites, have also been described in other Scleractinia (Kramarsky‐Winter et al., 1997; Rosen & Taylor, 1969). Unlike polyp bailout, in which detached polyps do not have skeletal remains, these polyps still retained parts of their skeleton. Asexual processes, that are similar to polyp bailout, have also been described in other anthozoans, such as zoanthids (Acosta et al., 2005), although this response does not appear to be stress‐induced, unlike polyp bailout, which has only been described under deleterious conditions (Fordyce et al., 2017; Kvitt et al., 2015; Sammarco, 1982). A counterpart to polyp bailout is apparently also found in hydroids. Here, hydranths can be released, become pelagic, and are able to resettle and differentiate (Gravier‐Bonnet, 1992). This process could also be a mechanism of reverse development. Processes of reverse development have been reported in several hydrozoans (Bavestrello et al., 2000; Piraino et al., 2004), scyphozoans (Laurie‐Lesh & Corriel, 1973), and anthozoans (Pearse, 2002; Piraino et al., 2004). Other processes may include development into dormant stages with greatly reduced metabolic functions (Piraino et al., 2004) and reverse development of adults to earlier developmental stages (Jackson & Coates, 1986). In Scleractinia, larvae of P. damicornis that had already settled and transformed into a primary polyp have been observed to undergo “reversible metamorphosis” by leaving their corallites and regressing to a planula‐like stage (Richmond, 1985; Te, 1992). This opens the possibility of finding more favorable sites for settlement and metamorphosis, which in turn hypothetically leads to higher survival rates.


Regardless, if it was caused by polyp bailout or asexual reproduction, I find it really interesting that they've been living happily in this floating pen for 3 1/2 months, and they just split into two seemingly very happy little cynarina corals! I feed them, and they poop, and they don't seem to be stressed at all!