Where are the polyps?

[JHawlz9989]

I don't understand why some of these corals are considered LPS. I've been doing a bit of research, because I would like to get some LPS corals in a few months once my tank is more mature.

With corals like acans, chalices, brain corals, etc., I don't see the polyps? Are they hidden somewhere underneath the skeleton (if that's what it is)?

Josh

 

[MechEng99]

Not really sure what you mean, but I'll try to explain it.

First of, the common classifications (softies, LPS, SPS) aren't true scientific classifications. They're just more for hobbyists to generalize coral needs. Polyps are each individual organisms that live in a colony or singularly.

If you're coming from soft corals (mushrooms, zoanthids, etc), then a mushroom is a "polyp", a single zoanthid is a "polyp", etc. These corals don't build a skeleton...instead they are made up of little calcium-based splinters that help support their weight. You may have noticed that in the center of each "polyp" is a mouth that can eat food.

SPS are "small polyped", and build skeletons.

LPS are "large polyped" in most cases, but there are some corals that blur the SPS/LPS line. Just like all other polyps, these too have mouths to eat and tentacles to catch food with. However, LPS are more likely to live singularly than SPS/softies (can't even think of an example for SPS.) In the case of "brain corals", they are often just one HUGE polyp (sometimes with multiple mouths.)

Here's an Acanthastrea coral of mine. Each individual main circle is a polyp. The inner circle is where tentacles come out, and the center of each polyp is the mouth.

Hope that helps!

 

[milhous3er]

Acans and brain corals are the polyps (the large fleshy part), mounted ontop of the skeleton. Not sure about chalice.

 

[MechEng99]

Sometimes "chalice" corals can be a bit difficult to find the polyps, but the different colored polyps in this one may help you to see them.

This is a rescue coral I saved. It has two mouths, but only one central ring of tentacles. Since the photo was taken, the two mouths have become two fully separate polyps.

 

[JHawlz9989]

So what exactly do they look like when the tentacles come out? I've never seen a picture of them like that.

Do they not follow the same lighting pattern as a zoanthid, in terms of open during the day and closed at night?

 

[MechEng99]

This is a non-photosynthetic coral, but it gives you an idea what the tentacles look like on some LPS:

Some LPS like Duncans (below) keep their tentacles out most of the time. Other LPS extend their tentacles at night and/or when there is food in the water column. Really just depends.

This is a photo of the same Acan I posted above with its tentacles out (kinda old photo, please excuse.)