Caulerpa nummularia

[Ninong]

What do you know about this species? I believe I have four patches of it on one piece of Kaelini rock. I don't have any corals in my tank yet, so it poses no danger of overgrowing anything at the present time. I have no fish either, so I don't know if it is a menu item for perhaps Zebrasoma spp. tangs?

Should I leave it alone or remove it now? My present plans are to leave it be and see what happens when I add my first herbivorous fish in the next two or three weeks.

Thanks,

 

[kmk2307]

Can you post a pic? I'm not familiar with that species. If you can't post a pic can you describe it? I'd venture to guess that a tang that ate other caulerpas would eat it.

Kevin

 

[ATJ]

Kevin,

Here's a photo:

Ninong,

It came into my tank as a hitchhiker and I used to think it looked quite cool. I now have to spend an hour every two weeks removing as much as I can, but it keeps growing back. I wish I'd gotten rid of it at the start.

I'm wary of feeding in Caulerpa spp. to fish because of the toxins. Granted different species have different levels of toxin but I think the fish would be better off without it.

 

[Ninong]

ATJ,

Thanks, that's what I was afraid of. Mine didn't show up until about four weeks after the rock was placed in the tank and so far it is only four patches confined to one large flat piece of live rock. It is growning quite rapidly; the largest patch went from invisible to 7 x 4 x 2 cm high within the past two weeks.

I think I will remove as much of it as possible tomorrow. I guess it spreads by fragmentation, too? So I will have to try to get all of the pieces out. I hate to remove that piece of live rock because it would involve removing several other pieces at the same time.

Thanks,

 

[ATJ]

I guess it spreads by fragmentation, too?

Yeah. Each "piece" of Caulerpa is essentially a single cell (coenocytic: multinucleate and without transverse cell walls) so there is no diferentiation into different cell types as you get with higher plants. Even a very small piece can develop all the necessary structures, blades, rhizome and rhizoid like outgrowths, once it has sealed itself to stop losing cytoplasm.