Hammer coral shape based on size or other parameters?

swiss1939 · Aug 21, 2020

I've picked up my first hammer coral frag the other day and am curious if the shape of the hammer polyps is dependent upon the size of the branch/head? Or is it related to flow/light? The frag I have has one main branch and the start of a tiny small head. On the main head, the hammer polyps are about 50/50 hammer shaped and oval shaped. they seem to be more hammer shaped in the middle of the head where the polyps are largest.. and more oval shaped toward the outside. The smaller head is all oval shaped polyps.

I am also looking at another frag to purchase of a very small hammer frag and all the polyps are more oval shaped than hammer. I am wondering if the size of the head/age of the branch is partly determining the development of full on hammer shaped polyps? Do they become more hammer shaped and pronounced the older and larger they get? Or is this fully dependent upon flow/light?

Here is the frag I just picked up the other day for example:

MaxxuM · Aug 21, 2020

My experience is with mammals so I'm guessing it would follow the same basic principal - genetic shaped by environment. They likely follow the trend inherited from the progenitor colony which is modified, with available DNA restrictions, by the environment.

LesPoissons · Aug 23, 2020

Hammers come in different shapes. Usually whatever shape you see on the most developed tentacles (longest) is the fully developed shape. The newer ones are closer to the base and take longer to develop the complete shape. I have seen hammers that are really crisp in their mature shape and some that are much more oval at full development but all the heads eventually take on the same shape as the fully developed heads. If that makes sense.

LesPoissons · Aug 23, 2020

From what Ive seen- these are just variations in species. Lighting/flow/water parameters doesn’t change the shape.

swiss1939 · Aug 23, 2020

Perfect that was what i was wondering. They form fully as the head develops. My frag has a lot of smaller polyps around the outside that aren't fully developed yet.