Coral?? or other

[designbysue]

Wondering what this might be - someone suggested sponge but I am not sure that is correct - looks like tentacles or something within the circles- looks coral like to me but the coloring was really different. Found this in Cozumel.

026 What is this?? IMG_8224

(sorry that this is a double post - I posted to the general board because I could not find this one)

Sue

 

[T.C.]

Sue, it's definitely a sponge. Note the large openings in the upper left corner. I believe these to be ex-current openings; where the sponge passes water out, while the openings with the 'tentacles' are the in-current openings, where the sponge takes in nutrient-laden water. I suspect the 'tentacles' are used for catching plankton for food as the water is taken in, or they may be a different animal colonizing the sponge to take advantage of the water flow.

My best guess would be a Lumpy Overgrowing Sponge. Hope this helps!

 

[RyanT]

It's not a sponge. There is a sponge in the upper corner growing there, but the main part of the photo is a coral. You can see the individual coral polyps on much of the colony.

 

[T.C.]

It's not a sponge. There is a sponge in the upper corner growing there, but the main part of the photo is a coral. You can see the individual coral polyps on much of the colony.

I have to disagree. The entire animal is indeed a sponge, look into the holes and you can see the internal divisions of the sponge, but there are colonies of hydroids or algae or something covering some of the openines. The white feathery animals are not part of it, but they're not a coral either.

 

[RyanT]

@T.C. On second look, I think you might be right. Typically you don't see other benthic organisms growing directly on sponges as they are pretty well chemically defended. But, looking closely between the polyps does indeed look more sponge-like. Perhaps what we are looking at here, is some individual hydrozoan polyps that the sponge has grown around.

 

[tursiops]

I'm thinking tunicate, maybe a Mottled Social (Polycarpa tumidda).

 

[cgills]

I'm thinking it looks like a cluster/colony of small thin disc shapes, probably Corallimorphs covering the top a an encrusting sponge.

 

[KeithG]

I am with TC. I claim the underlying thing is a Lumpy Overgrowing Sponge. Humann has a very good picture.

The question is what (if anything) is growing on the sponge? I see small white branching growths growing from the inside edges of many of the sponge openings. The edge of these openings also have flared outwards and flattened towards the sponge body. The lower right area of the photo provides some good detail of the white branching growth on several openings.

The white branching stuff does not match any feature on any creature I know. Tunicates have smooth mouths, no white branching whiskers. Same with Corallimorphs and Zoanthids. So I do not think the openings are another creature that the sponge is encrusting.

Maybe it is a hydroid infection of some sort? Or simply a natural sponge growth that is not well documented.

 

[T.C.]

I am with TC. I claim the underlying thing is a Lumpy Overgrowing Sponge. Humann has a very good picture.

The question is what (if anything) is growing on the sponge? I see small white branching growths growing from the inside edges of many of the sponge openings. The edge of these openings also have flared outwards and flattened towards the sponge body. The lower right area of the photo provides some good detail of the white branching growth on several openings.

The white branching stuff does not match any feature on any creature I know. Tunicates have smooth mouths, no white branching whiskers. Same with Corallimorphs and Zoanthids. So I do not think the openings are another creature that the sponge is encrusting.

Maybe it is a hydroid infection of some sort? Or simply a natural sponge growth that is not well documented.

As Ryan said, I think those are a hydrozoan of some sort

 

[cgills]

I am with TC. I claim the underlying thing is a Lumpy Overgrowing Sponge. Humann has a very good picture.

The question is what (if anything) is growing on the sponge? I see small white branching growths growing from the inside edges of many of the sponge openings. The edge of these openings also have flared outwards and flattened towards the sponge body. The lower right area of the photo provides some good detail of the white branching growth on several openings.

The white branching stuff does not match any feature on any creature I know. Tunicates have smooth mouths, no white branching whiskers. Same with Corallimorphs and Zoanthids. So I do not think the openings are another creature that the sponge is encrusting.

Maybe it is a hydroid infection of some sort? Or simply a natural sponge growth that is not well documented.

I'll go with your Lumpy Sponge identification, but still feel the growths on top are a type of Warty Corallimorph colony.( Humann Creatures 3rd edition, pg 46,MR photo.) Unfortunately the detail in the above photo of is a bit lacking,but believe the feathery bits are the forked extensions, surrounded by the translucent edge of disc.
Have seen similar here diving Grand Cayman in the shallows,<60ft.