Sponge, tunicate, or ?

[cappyjon431]

I'm having trouble identifying these critters. The pores make it look like a sponge, but it could be an encrusting tunicate with syphons. Any ideas?

 

[archman]

My first guess is a funky-colored Porites, but if it's soft and squishy, I'd go with Strawberry Tunicate. They come in shades of purple.

 

[David P]

I wish there was something in the photo for scale. I have seen something just like that in red instead of purple and they developed into a type of algae. They were kinda spongy/kinda slimy... Then again, I've also seen a lot of growth like this in white and yellow, and they are sponge. Do you have any more info on the growth


Archman, if those were porites, Id love to have some in my tank!

 

[archman]

I am unaware of any Caribbean macroalgae that look that that.

 

[divingjade]

Hello, I work on sponges for my PhD and I am pretty certain that is a tunicate.

Sponges can be difficult to tell apart from other benthic organisms, particularly some ascidians (sea squirts or tunicates). All sponges have ostia (pores), which is where the water enters the sponge, and at least one oscule (larger holes) for the water to exit the sponge. Ascidians either have two siphons to allow water in and out or they have very regularly arranged small oral siphons; sponges generally don’t tend to have very regularly arranged oscules. The easiest way to tell them apart is to gently waft your hand near the animal, if the animal contacts its openings quickly it is likely to be an ascidian. Sponges can contract, but they do it much more slowly. Finally, if you look very closely at the smaller openings of an ascidian they are likely to be star shaped and they also look more regularly spaced than most sponges.

Hope this helps!

 

[stoyleg]

These are almost certainly compound tunicates - most likely Strawberry (Eudistoma sp.) which vary in colour from purple to red.

 

[Soakedlontra]

Hello, I work on sponges for my PhD and I am pretty certain that is a tunicate.

Sponges can be difficult to tell apart from other benthic organisms, particularly some ascidians (sea squirts or tunicates). All sponges have ostia (pores), which is where the water enters the sponge, and at least one oscule (larger holes) for the water to exit the sponge. Ascidians either have two siphons to allow water in and out or they have very regularly arranged small oral siphons; sponges generally don’t tend to have very regularly arranged oscules. The easiest way to tell them apart is to gently waft your hand near the animal, if the animal contacts its openings quickly it is likely to be an ascidian. Sponges can contract, but they do it much more slowly. Finally, if you look very closely at the smaller openings of an ascidian they are likely to be star shaped and they also look more regularly spaced than most sponges.

Hope this helps!

Hello Divingjade! I am wondering if you also study sponges that live in the Pacific Northwest.

I am not sure whether these two guys (the yellow on the left and the red on the right) are the same animal but with different colors or they are two different kinds of sponges. Well I think that is what they are. Aren't They?

 

[divingjade]

Hello there,

I've not worked in the Pacific Northwest I'm afraid! I can tell you that from the photo definitely two different organisms. I would say the yellow one is a demosponge but it is hard to tell exactly which one without a close up as I can't see the surface detail and ideally a sample so I can see the skeleton (spicules). The red one I think is a compound ascidian, but it could be a sponge again I would have to look a bit closer! Did they both have the same pattern of of pore distribution on their surfaces?

 

[Soakedlontra]

Hello there,

I've not worked in the Pacific Northwest I'm afraid! I can tell you that from the photo definitely two different organisms. I would say the yellow one is a demosponge but it is hard to tell exactly which one without a close up as I can't see the surface detail and ideally a sample so I can see the skeleton (spicules). The red one I think is a compound ascidian, but it could be a sponge again I would have to look a bit closer! Did they both have the same pattern of of pore distribution on their surfaces?

Thanks for your reply. I will try to get a close up of both organisms next time I go snorkeling or diving at Keystone. My humble underwater camera cannot get really, really close without blurring the subject.

When I took this picture I was snorkeling and it was a bit hard to keep myself steady and at the same time pay attention to their surfaces so I have no idea what kind of pattern of pore distribution they have.

 

[divingjade]

Good to see pictures of sponges anyway! good luck with your new photos I know how frustrating it is when you come up and your picture looks nothing like what you though you saw but the pic is good sponges are just hard to ID