ID Please

[melev]

This unknown creature was in my refugium. I thought it was kinda cool, until last night when it caused about 1/3 of my caulerpa to die (bleed green fluid to death). Any ideas what it is? For now, it is out of my tank.

Click for picture of kritter

Thank you. And Ron, thanks for coming to Macna, and for your lecture.

 

[~ChrisB~]

From what I understand those slugs are kind of common when it comes to caulerpa. I think I've read that they "suck" some of the insides out of the algae for food. I'll look around to see if I can find the thread I read about these guys.

 

[~ChrisB~]

Try this thread.
Click for Sluggish info!
Or try here!

 

[melev]

Try this thread.
Click for Sluggish info!
Or try here!

Thank you very much, as both articles sound just like my guy. I don't like how much of my caulerpa he decimated in the past few days. After all, I've been trying to build up my refugium since I set it up 45 days ago, and truly about a 1/3 is dying as I type this, now that it has been punctured by this slug's tooth.

For now, he is in a little bowl with a sprig of caulerpa, but I don't really feel inclined to put him back in my 'fuge any time soon.

Marc

 

[Mike_Noren]

Re: ID Please

This unknown creature was in my refugium. I thought it was kinda cool, until last night when it caused about 1/3 of my caulerpa to die (bleed green fluid to death). Any ideas what it is? For now, it is out of my tank.

Click for picture of kritter

I'm not Ron, but I'd say that's an Elysia. Not a nudibranch, but a shell-less snail, a saccoglossan.

They're herbivores, and some species are among the very few animals who'll actually eat Caulerpa (since Caulerpa is toxic). One caribbean species of Elysia is considered for introduction into the Mediterranean, to deal with the outbreak of Caulerpa taxifolia swamping large tracts of the western Mediterranean.

If Ron like me is unable to ID your slug, and you want to try to find out what species you've got, you can go to www.seaslugforum.net, and look at the pictures there. If you cant find your guy, they'll help with identification too.
My guess is that they might be quite interested in a slug known to eat Caulerpa.

If you for some reason actually _want_ Caulerpa, then you don't want to keep that snail.

If you lived closer to here I'd love to take it off your hands - I find Caulerpa among the most aggressive weeds there are, almost impossible to eradicate or even control, and I'd welcome anything which attacks it.

 

[Mike_Noren]

Re: Re: ID Please

Re: Re: ID Please

I'm not Ron, but I'd say that's an Elysia.

Upon reflection I think it may instead be a relative of Elysia, another sacoglossan called Oxynoe. Try this one on for size:
http://www.seaslugforum.net/oxynanti.htm#m3120

The rest of what I said still stands.

 

[~ChrisB~]

..............................................

 

[melev]

Re: Re: ID Please

Re: Re: ID Please

I'm not Ron, but I'd say that's an Elysia. Not a nudibranch, but a shell-less snail, a saccoglossan.

They're herbivores, and some species are among the very few animals who'll actually eat Caulerpa (since Caulerpa is toxic). One caribbean species of Elysia is considered for introduction into the Mediterranean, to deal with the outbreak of Caulerpa taxifolia swamping large tracts of the western Mediterranean.

If Ron like me is unable to ID your slug, and you want to try to find out what species you've got, you can go to www.seaslugforum.net, and look at the pictures there. If you cant find your guy, they'll help with identification too.
My guess is that they might be quite interested in a slug known to eat Caulerpa.

If you for some reason actually _want_ Caulerpa, then you don't want to keep that snail.

If you lived closer to here I'd love to take it off your hands - I find Caulerpa among the most aggressive weeds there are, almost impossible to eradicate or even control, and I'd welcome anything which attacks it.

I agree with your second post, as well as Tank's, it seems to be close to the Oxynoe antillarum. Mine doesn't have hair on it like those pictures, but is smoother. Plus it is bright green, especially after the lights have been on for a while. One oddity about this guy is his tail section. If you get to see a view of him from above, right behind his body (carapace?), the tail section begins, but it looks like two pieces that touch closely. Between the body and the tail, there is a hole, and you can see right through it! The tail looks almost like tails on a tux, if that makes any sense.

And I was just looking at my refugium, and I'd say half of my caulerpa is gone now. :mad2: I just put fresh water on this guy, so he's still in the bowl, but I'm not sure why I'm keeping him alive.

Last night, my refugium turned pure green (looked like a bottle of DTs) and my display tank was the same color. As we know, caulerpa takes up nitrates, but I'm wondering what happens when the green liquid bleeds out into the water column, does the nitrate rise again? Huge globules of green leaked out of several portions of the plant, and now I have quite a bit of clear/white plant that will likely dissolve today. What a mess!

By any chance, was that leaking green fluid beneficial to something else in the tank? Mushrooms, Leather coral, SPS's, anemone or clams?

 

[Mike_Noren]

Re: Re: Re: ID Please

Re: Re: Re: ID Please

I agree with your second post, as well as Tank's, it seems to be close to the Oxynoe antillarum. Mine doesn't have hair on it like those pictures, but is smoother.

There's several Oxynoe species, e.g. this unidentified one collected in a Brazilian reef tank:
http://www.seaslugforum.net/oxynsp1.htm
And it seems the species are quite varied in shape and coloration too.

Between the body and the tail, there is a hole, and you can see right through it! The tail looks almost like tails on a tux, if that makes any sense.

I'm not sure quite what you've seen, but there's folds covering the shell (Oxynoe has a reduced transparent shell, whereas Elysia completely lacks shell). Possibly you're seeing those folds.

Last night, my refugium turned pure green (looked like a bottle of DTs) and my display tank was the same color. As we know, caulerpa takes up nitrates, but I'm wondering what happens when the green liquid bleeds out into the water column, does the nitrate rise again? Huge globules of green leaked out of several portions of the plant, and now I have quite a bit of clear/white plant that will likely dissolve today. What a mess!

I don't think the snails is the culprit - it sounds like if your Caulerpa has gone through sexual reproduction. The snail might have hastened the process, but it would have happened anyway. Caulerpa reproduces sexually when it reaches a certain size.

And yes, this means that a lot of organic material, with quite a bit of nitrate, has been released into your aquarium.

By any chance, was that leaking green fluid beneficial to something else in the tank? Mushrooms, Leather coral, SPS's, anemone or clams?

It's conceivable filter-feeders might eat it, but considering that Caulerpa is quite toxic, I sortof doubt that they do.

 

[rshimek]

Hi,

Well, the unknown animal is definitely a sacoglossan. For the time being, the species is immaterial.

It will not cause the "bleeding" of Caulerpa, in fact these animals eat the alga and this would tend to reduce any chance of the "bleeding."

The "bleeding" is caused by the alga sexually reproducing and this, in turn, is caused by the Caulerpa individuals getting large. This may be prevented in the future by "pruning" the alga and discarding the excess. Or by introducing a lot of the slugs...

As Mike has indicated. [thanks], the spawning alga can cause a lot of nutrient excess in the tank, and additionally - depending on the clone of Caulerpa, it may release a lot of toxic metabolites (some spawnings don't seem to, some do - it is rather the luck of the draw which you have.).

Clams, and other herbivorous suspension feeders often seem to really "love" this food (the green cloud is composed of flagellate unicellular algae, and for those animals that can eat it, it is quite nutritious).

 

[melev]

Thank you for your replies. I never received notification from RC that there were new messages in this thread.

Since you both mentioned the caulerpa going sexual on me, I need to know what to do in the future to prevent that. I set up my refugium about 6 weeks ago, with one small handful of caulerpa, which grew and grew. It was filling the void nicely, but no where near the entire area.

If I'd pruned it out, I'd have lost my 'starter', imo. Also, when pruning, how do you prevent the green leakage I observed? Or will it not leak when it is torn or cut? It only leaks when it goes sexual?

Since I have very little growing now, do I simply cut these pieces in half, and in a couple of weeks cut it again in half, to establish multiple vines?

And lastly, does my small friend have the right to return to the refugium after all?

 

[rshimek]

Originally posted by melev

Hi Marc,

Thank you for your replies. I never received notification from RC that there were new messages in this thread.

It is best simply to check the threads. I reply to every thread posted from Saturday through Wednesday, Thursday and Friday posts get ignored as those are my "days off."

Since you both mentioned the caulerpa going sexual on me, I need to know what to do in the future to prevent that.

You need to periodically prune it back. Sexual reproduction appears to be a size related phenomenon in many of the green algae.

If I'd pruned it out, I'd have lost my 'starter', imo.

Not likely. When it is rapidly growing you can often take out about half of the algae.

Also, when pruning, how do you prevent the green leakage I observed? Or will it not leak when it is torn or cut? It only leaks when it goes sexual?

Each Caulerpa plant is a single large cell. When you prune it, the cell sap or cytoplasm will leak out a bit, but it will seal itself off and continue to grow.

Since I have very little growing now, do I simply cut these pieces in half, and in a couple of weeks cut it again in half, to establish multiple vines?

Sure, but consider in that case you simply have cloned it.

And lastly, does my small friend have the right to return to the refugium after all? [/B]

Oh, sure. It will eat the algae, but probably not enough to slow it down.

 

[davidryder]

Did you decide on removing it or not?

 

[melev]

I returned it to the LFS where it came from so it could decimate HIS macro algae instead of mine.

 

[zoozimmy]

wow