Unknown Sphere

[Darelor]

I cannot find anything that matches the description of what I found during a dive October 20, 2006. I am pretty sure it is organic.

Description:

Located at 20' in a sandy area of Lake Lanier in North Georgia
8" sphere, gray-colored with white markings distributed all over
The sphere was on top of a 1" pedestal about 1.5" long
Found two other spheres 2" in diameter in the area
The smaller spheres were the same color and marked the same way
The smaller spheres felt semi solid, but not gelatinous

I have a cruddy picture of it, but have not tried to post it yet.

Any ideas?

Thanks,

Darel

 

[Darelor]

OK, I posted the photo in Photo Gallery in Underwater Marine Animals. Search for darelor.

 

[archman]

http://www.scubaboard.com/gallery/showphoto.php/photo/61143/limit/recent

Looks like a sponge.

 

[mislav]

Any ideas?

Of course, always. Look here!

 

[Diver0001]

http://www.scubaboard.com/gallery/showphoto.php/photo/61143/limit/recent

Looks like a sponge.

... or a tennis ball.

R..

 

[Darelor]

http://www.scubaboard.com/gallery/showphoto.php/photo/61143/limit/recent

Looks like a sponge.

Interesting, Archman. Have you seen one of these in other bodies of freshwater?

For the sake of further analysis, aren't freshwater sponges non-symmetrical and gelatinous? If this is a freshwater sponge that for whatever reason formed into a sphere, is it likely that the pedestal is a stick around which the sponge formed?

Thanks,

Darel

 

[archman]

It's the phylactolaemate bryozoans which are gelatinous; freshwater sponges (or all sponges I'm aware of) have a *crunchy* outer texture to them.

The only freshwater sponges I've encountered were asymmetrical and attached to the ends of submerged branches in deep lakes. However they'll occur in a variety of limnetic habitats. Judging from your description of the thing's texture and what visually appears to be oscula on the top of it, I'm guessing it's some sort of sponge. I'm not sure what else it could be, assuming it's a live critter.

 

[Darelor]

Thanks, Archman. I'm pretty sure it's alive. That's why I'm not going to disturb it. What I will do is try to locate it again and take better pictures of it. That layer of water in Lake Lanier is clear at this time of year. I just hope I can find it again. Perhaps there are others out there I will see.

This one just surprised me because of its size and symmetry.

So, do you have enough info to determine a scientific name for this thing?

 

[archman]

If you can get some closeup pics and describe in more detail how it *feels* when you touch it (I'm looking for "sandpaper"), I can probably verify that it's a leuconoid sponge. Take a close look at the "stalk" as well; it may be part of the sponge.

That's as far as I can go with it. Sponges are a pain in the butt to ID, even in one's local area... which I'm not.

 

[Rick Murchison]

Sponges are a pain in the butt to ID

Yes, yes... that's probably why many field guides say something like "positive identification requires microscopic examination of specimen."
Rick