What is this ridge on my BTA

[dantodd]

I was looking at my BTA today and noticed a ridge around the underside of it's oral disk.

It's hard to see the scale but there is about 1" from the ridge to the edge of the oral disk. It goes comletely around the anemone.

Any idea what it is?

 

[Flighty]

That is a normal feature on some BTAs and Magnificas. I have no idea what it is called, but I always refer to it as beading because that is what it looks like to me.

you can see it on this bta

 

[dantodd]

Interesting, on yours it looks like the 'beading' is right at the edge of the oral disk. On mine there's a good inch between the 'beading' and the edge. Love those purple footed BTAs.

 

[Amphiprion]

All true anemones have this characteristic. I cannot recall what it is exactly (something like a "cuticle")

Here is a pic of the underside of my H. crispa showing the same thing

 

[Flighty]

should we rename the thread "show me your cuticle" ?

H. Magnifica

 

[Gary Majchrzak]

This picture shows the veruccae {warty bumps} located on the upper column {gray area} of a Haddon's carpet anemone.
The fringing finger-like projections forming a collar on the upper column just below the oral disc are structures know as acrorhagi, used in aggression with other anemones.

Here are the same features as seen on a Macrodactyla doreensis

 

[dantodd]

That makes a lot of sense Gary. I noticed that he keeps trying to use the acrorhagi to attach to LR and some algea that is growning near him. I thought it odd that it acted a little like a foot in that regard and thought maybe it was to help him stay open in strong current. Using it to create a colonial group makes more sense.

 

[Amphiprion]

That is the name I couldn't recall at the time, but that only applies to certain other genera. However, Stichodactylids (neither E. quadricolor or M. doreensis) do not use them (nor do they possess true acrorhagi) for defense. There is a negligible to nonexistent concentration of holotrichs, so they are utterly useless in a defensive regard in these anemones.