C. Recemosa (grape Caulerpa)

[yorkcoparamedic]

I recently purchase a handful of macroalgae from my LFS which consisted of Chaetomorpha sp. and C. Recemosa. I've heard that if C. Recemosa gets stressed it will go through sexual re-production and release toxins into the tank. Is this true? If so how bad is this and how do I safe guard against it happening?

As of now it is in my above tank refugium w/ ample lighting 24/7 and also dosing of Green to help it grow.

Has anyone also heard of dosing Fe (iron) to the tank and/or refugium to ward against sexual re-production of C. Recemosa?

 

[lljdma06]

I recently purchase a handful of macroalgae from my LFS which consisted of Chaetomorpha sp. and C. Recemosa. I've heard that if C. Recemosa gets stressed it will go through sexual re-production and release toxins into the tank. Is this true? If so how bad is this and how do I safe guard against it happening?

As of now it is in my above tank refugium w/ ample lighting 24/7 and also dosing of Green to help it grow.

Has anyone also heard of dosing Fe (iron) to the tank and/or refugium to ward against sexual re-production of C. Recemosa?

If you wish, I can move this to Saltwater, but I did some research, and I can at least point you in the right direction. From what I've read, C. racemosa will begin a period of die-off as it becomes sexual, which can foul the tank due to its decomposition and the release of the components of sexual reproduction. It's decomposition can trigger algae blooms and other problems associated with an excess of nutrients in the Marine System. The advice I've read has been to remove the dead portions upon seeing the warning signs (whitening portions, followed by desintegration), and good maintenance (larger water changes, etc). Regular thinning, not cutting or pruning, which can cause the caulerpa to "bleed" into the tank, also supposedly prevents the plant from going "sexual". Some people also insist on keeping it in a separate refugium with lights on 24/7 (which you are currently doing) to prevent it going sexual, but others say that this has no effect and can damage other organisms in the refugium. Nudibranchs, some sea hares, and some fish also prey on it, but again, other hobbiests have not found this to be effective either. Basically, the advice has been to keep on top of the caulerpa by regularly thinning it and watching for whitening portions. I couldn't find any information on whether or not dosing Fe has any effect on it going sexual.

Would you still like me to move this?

llj

 

[yorkcoparamedic]

Yes you may move this post. I was not sure where to place this post and this seemed the most logical to me. Thanks for your research! I have been doing some myself and was able to find the info that you provided. But I did find info on lighting and new research into Fe dosing.

Thanks again and if it is not to much trouble could you give me the links to the source of your info about the color changes in the Racemosa.

 

[andywg]

Caulerpa will go "sexual" when conditions for growth are less than optimal. It seemns this most comomnly happens in larger tanks where the macro is just left to grow and grow until it encounters areas that are less than ideal (buried with little light and flow). 24/7 lighting and regular pruning should see you fine (it certainly has for me for a year).

Also, the going sexual will just release nutrients already absorbed fromt he water, while not ideal it is not like a boxfish dying and nuking the tank.

I would advise against dosing green and iron to kep the macro growing. You are growing the macro as nutrient export, not to add more nutrients to try and get the exporter to work.

 

[chrissaysyes]

Also, caulerpa will turn transparent or white when it needs pruning, it's really easy to keep tabs on. Definitely my favorite macro for display tanks.

 

[Lynden]

Halimeda is the only macro algae, as far as those species I am aware of, that will turn white when healthy as the chloroplasts migrate to the rhizoids at night. When any other algae turns white or see through it is a bad sign, and even with Halimeda it is only at night and early morning that they should be white.

 

[Donya]

I recently purchase a handful of macroalgae from my LFS which consisted of Chaetomorpha sp. and C. Recemosa. I've heard that if C. Recemosa gets stressed it will go through sexual re-production and release toxins into the tank. Is this true? If so how bad is this and how do I safe guard against it happening?

As of now it is in my above tank refugium w/ ample lighting 24/7 and also dosing of Green to help it grow.

Has anyone also heard of dosing Fe (iron) to the tank and/or refugium to ward against sexual re-production of C. Recemosa?

Eh...tons of toxins, no. I've never seen anything die from it, and given that many things eat it, I can't think that anything contained in that stuff is too bad. If it goes sexual you'll mainly get lots of excess organics that will decay and suck O2 out of the water if not filtered out. If you want to safe guard against any Caulerpa species going sexual:
- no snails that will bite through large stems (e.g. stay away from large Turbos).
- no snails or hermits that are heavy enough to risk crushing it or damaging it if they fall on it.
- have a backup air supply that isn't from surface aggitation. Use an air bubbler, venturi tube to a powerhead, etc.
- remove any badly damaged or fading sections that you find.
- if you prune, don't just cut/tear it and throw it back in. You need to pinch the main vascular sections off for a minute or two before cutting it and then keep the exposed ends out of the water for some time so they dry and don't risk the macro bleeding out into the tank. Sudden fluid loss can trigger going sexual, and also if the fluid loss is rapid enough it will have the same effect on the water as going sexual but the macro will just die instead.
- if the water goes green anyway, do a water change, check the bubblers to make sure they're supplying enough O2 to animals, and wait for it to clear up. 24/7 lighting won't necessarily help the growth, or do anything to keep it from releasing spores. 12h on/off is what I've found to give optimal growth in my macro.

 

[steelhealr]

A lot of good information above. Some people have reported that it takes on a whitish color before going sexual. Personally, I don't like it in nano tanks. Chaetomorpha is an excellent alternative. In a large tank, I see no issues with using caulerpa. JMO. SH

 

[andywg]

- have a backup air supply that isn't from surface aggitation. Use an air bubbler, venturi tube to a powerhead, etc.

Why away from surface agitation? bubbles from air stones and venturi are not in the water anywhere near enough for meaningful gas exchange to take place. they only contribute to getting rid of CO2/getting in more O2 by increasing surface area for gas exchange.

Unless you are proposing some form of diffuser as is oft used in planted FW aquaria with CO2 injection...

 

[Donya]

- have a backup air supply that isn't from surface aggitation. Use an air bubbler, venturi tube to a powerhead, etc.

Why away from surface agitation? bubbles from air stones and venturi are not in the water anywhere near enough for meaningful gas exchange to take place. they only contribute to getting rid of CO2/getting in more O2 by increasing surface area for gas exchange.

Unless you are proposing some form of diffuser as is oft used in planted FW aquaria with CO2 injection...

Good water flow with 20-30x turnover aimed right will have good surface aggitation, but having experimented with this quite a lot myself, I can tell you that the surfice aggitation alone, particularly in smaller tanks, is not sufficient when a large enough volume of macro decides to turn into goo or bleeds out due to physical damage. Fish gasping at the surface in response to macro having bled out or gone sexual overnight with all tank params still in check indicates sudden lack of O2 that surface aggitation isn't compensating for. The same can happen with phyto blooms, as I've also seen prior to keeping macro. The issue is aleviated with the introduction of an air source deep in the tank that produces very fine bubbles (although not appreciably more surface aggitation - I tried more aggitation and it flat out didn't work in my largest macro tank). I saw this several times in my various tanks before I figured out the O2 was the root of the problem with trial & error use of airstones, and after introduction of a fine bubbler or venturi tube that produces large amounts of quite fine bubbles, it takes about 10 minutes for the fish to stop gasping at the top. Once those were in place, the gasping never occured with later events stemming from physical damage to the macro. Larger tanks would require something more along the lines of a diffuser as you've mentioned. Bigger tank, heavier duty equipment. I did not mean to imply that dropping an airstone with an insignificant pump in a 50+g tank will fix the problem (although the effect of macro problems will decrease with larger water volume) - what you put in has to be proportional to the tank size and volume of macro that risks becomming decaying particles.