Toxic effects of wounding Caulerpa
 

Well after a couple events that were unexplainable I spent the last week looking for a commen thread.

The events were 1, polyps on my digitata closing up for over a week, and two the loss of my Bangii.

The only commen factor was the large harvest of Caulerpa, digitat was closed up for a week after this and the next time I did it about 3 days after my bangii started having problems swimming and I put him down.

so after doing some reaserch I have came up with the following.

C. taxifolia and C. racemosa are the two most dangerious ones, C. taxifolia being a semertical feather Capulera and C. racemosa being the coment Grape caulerpa.

"Among the many secondary metabolites produced by algae belonging to the genus Caulerpa, caulerpenyne (CYN) is the most abundant cytotoxic sesquiterpenoid to be released."

"CYN, thought to be the most active substance, is involved either in
the chemical defense of the plant against herbivore pressure or within the framework of interspecific competition (antifeedant and antifouling effects)"

"A variety of toxic effects due to CYN have been demonstrated in several
organisms at different stages of their growth. The most harmful effect is on sea urchin eggs, which are killed by CYN (Lem´ee et al., 1993). This molecule, therefore, represents a potential danger to organisms"

"C. taxifolia and C. racemosa react upon wounding with rapid transformation of its main defensive metabolite caulerpenyne. The three acetate groups of this sesquiterpene are enzymatically cleaved within minutes after mechanical damage."

"The significant decline in abundance of amphipods and isopods would have ramifications along the food web"


Anyways this has opened a whole new can of worms for myself and to adjust for it I will be adding fresh carbon when I do harvests.. when I move this fall I will be scouring every chunk of rock I have in a attempt to remove it from my system.

Now I am also hopeing that other might have witnessed results like i have or maby others and have more to add to this descussion. maby some fool proof ways of removing this? To me a small rabit fish is looking better all the time :mrgreen:

Steve

Very interesting Steve although I havent had any ill effects. Makes me not want to harvest the refugium :wink:

I am stuck with this annoying grape caulerpa in my rock work. It pokes its ugly head out everywhere. I need to get a macro eater!

When I harvest caulerpa there is this clear sticky stuff that comes from it is this the CYN?

when you rip a chunk under water it looks like it is "Leaking" a fluid out.. the "CYN" is part of that.

Steve

Get info! I'll keep the carbon handy... :n00b:

Does it make any difference if you "rip" it out or "cut" it out? I usually use scissors to cut mine out (like a fish biting it off) and I've never noticed any fluid leaking out.

Well, I don't know if it the same with plants as it is with animals & humans but a ripping / tearing injury elongates the tissues as they are quite elastic & actually can help reduce fluid loss as they are stretched. A straight laceration doesn't do this, think of it like cutting a garden hose, quite a bit of fluid loss can occur.
Creepy little bits of knowledge from work... :eek:

although blunt scissors would create a compression injury & help seal it off, hmmm..... :painting:

I get the leakage either way. I have tried snipping and ripping.

Steve

Steve

Where is the quote from ?


Wendell

Re: Toxic effects of wounding Caulerpa
 

I'm with you on this one, I once considered a rabbitfish as a cure to my situation, but opted against it thinking that my tank is too small, now once again I'm considering it because I just can't keep up with pulling this stuff out. If something eats this stuff, then I want it to live in my tank for a while. I guess I'll just have to be prepared to deal with a growing fish. Either hope that a good home can be found when he gets too big, or be able to whine loud enough to be allowed to set up a bigger tank.

In general I don't really have a whole lot to add to your observations there, Steve. ... I've come to more or less the same conclusion. I'm not fully against keeping caulerpa in a refugium, but not keen on it in a main tank with lots of nooks and crannies that are a complete impossibility to access properly.

One other thing, it's been noted before than when pruning caulerpa, sometimes the entire colony crashes. Seems to not happen that often, but I think it does illustrate that there is "stuff" that gets released when it's pruned. Running carbon and polyfilter is probably a sage thing to if going to do some extensive pruning.

I'd really be keen on a eelgrass refugium, but since I don't have any of that, I'm more or less stuck with the caulerpa for now. I also grow some cyanaria (sp.?) - spaghetti algae, some sargassum, and some halimeda. Halimeda is kind of cool, but like caulerpa it does sporulate periodically. Don't know what risk of toxins or allelopathic inhibition each species has though -- I just live with the risk and hope that I'm doing enough to keep it under control.