Confused on the difference between zoa and poly

[AC0DX]

So I am a saltwater rookie. Can some one explain the difference between a zoa and a poly? I assume this rock has 5 zoas and 1 poly?

 

[sbash]

Did you see this video:

 

[AC0DX]

Did you see this video:
No I hadn't, but now I have. I can't say that helped a lot. But it was very interesting.

 

[sbash]

No I hadn't, but now I have. I can't say that helped a lot. But it was very interesting.

lol, indeed...

Basically, there are some palys that we know are not zoas, and most zoas we know are not palys. However, genetically speaking they are extremely similar, so there are several species in the middle somewhere; so nobody really knows, even if they claim to.

That said, given the ridiculous and non-scientific names we seem to be giving these creatures; I'm not sure it really matters... lol...

Unfortunately, there is very little science happening around coral genetics (leading to certainty around species identification). Sure there is some, but we will not really know anything tangible (i.e. meangingful, especially for the hobby) for a long while. Even in the hobby we have very few legitimate scientists to help out; so we are stuck with an unsafe amount of anecdotal observations and situations.

I will say, however, there is one we know for sure, beyond any doubt... and that is the hasselpaly...

 

[BoomCorals]

The vast majority of palys have substrate incorporated into their skin and stalks. The vast majority of zoas do not. That's one of the easiest ways to determine which is which. Make them close up with your finger or something and then see if the skin is smooth or rough/sandy looking.