Difference betweem Palythoa and Zoanthus...

Here's a start, technically, palys are zoas (but neither taste like chicken):
Zoanthids commonly kept in aquaria belong mainly to six genera, Zoanthus, Protopalythoa, Palythoa, Isaurus, Acrozoanthus and a possible new genus for the zoanthid commonly called "yellow polyps".  (

 

So it's kind of like how you can call a sandal a shoe but you wouldn't call a shoe a sandal?

 

Good topic for discussion.

This isn't very scientific, but in my own opinion and experience I will describe how I classify a palythoa.

Palythoas are usually a little larger and thicker than most zoas. They usually will eat frozen food where most zoas will not. You can observe them closing up around the food like a venus fly trap. Usually Palythoas have stripes in them and have a little bit of a metallic shimmer (look like human eyes). Yet that doesn't mean they are certainly a palythoa as some zoas have these features as well. They also seem to be more hardy and less likely to catch diseases/parasites/fungi. Keep in mind this is just what I have observed and it doesn't mean that it is necessarily correct.

I hope some others will chime in about this subject...

 

I agree with lee. The skirts on palys seem to be fewer where on a zoa they are usually thick & close together

 

you got any pic's of what you are trying to ID.

 

I agree with Lee.......Paly's will close up around food, whereas zoanthids do not and are generally larger.