If this isn't a gorgonion, what is it?

[Steve_S]

Great Forum here! I really think the way these forums are run are a wounderfull and welcomed changed to the diving Industry!

=-)

 

[Frank O]

Ran across this about a week ago in one of the coves at Catalina Island in Southern California:

http://www.inkbox.net/catalina/gorgonion-like.jpg

Is this some kind of invasive something-or-other that's covered up the 'branches' of a possibly dead gorgonion? (Just taking a wild guess.)

 

[archman]

Looks like a gorgonian to me. A lot of the (relatively) deeper dwelling species have that bumpy-looking outer tissue. Swiftia's a bit like that.

You can see the gorgonin core visible at the tips of the branches on the upper right.

 

[JustinW]

looks like a gorgonian to me. Seems that the polyps are closed at the time of the photo. You can certainly see the dead tissue on the end, typical of gorgonians that may have suffered some sort of damage.

 

[Frank O]

Thanks, guys. In this case this gorgonian wasn't deep -- I think we were only in about 15-20 feet of water, give or take.

Seems that the polyps are closed at the time of the photo.

As a gorgonian newbie, I'm curious -- do the polyps tend to be closed at any particular times more so than others? Such as -- younger gorgonian; older gorgonian; time of day; water temperature; anything else?

 

[MaxBottomtime]

It looks like the polyps are just closed. Being filter feeders, they rely on water movement to bring the food to them. If there was little or no current when you took the picture it's likely it was Gorgonian nap time.

 

[scottfiji]

From frontside Catalina last week:

http://www.inkbox.net/catalina/gorgonion-like.jpg

Is that some kind of invasive something-or-other that's covered up the 'branches' of a possibly dead gorgonion? (Just taking a wild guess.)

Can't say i've seen that before, but now I'll keep my eyes open for it.

 

[archman]

As a gorgonian newbie, I'm curious -- do the polyps tend to be closed at any particular times more so than others? Such as -- younger gorgonian; older gorgonian; time of day; water temperature; anything else?

When it comes to gorgonians, heck virtually everyone is a "newbie". They're tough to differentiate, and most divers don't think they're worthy of close attention.

Regarding polyps, many gorgonians feed during the day, so their polyps are extended. They don't seem as cued into diurnal feeding cycles as do most of the hard corals, or at least the zooxanthellate forms. Although as a caveat, some gorgonians possess zooxanthellae too. Stress appears to be a major factor affecting polyp closure. Common stresses include physical contact (especially repeated physical contact), heavy siltation, and fluctuating salinity and/or temperature.

I'm hoping to more closely observe various Caribbean species this summer, in a class I teach. I will certainly keep questions like the ones being brought up in mind.