ah.. ok.. i believe it is said that a 24 hour photoperiod with Caulerpa can prevent it for going sexual. and Caulerpa can handle it, but Chaeto and other macros algaes can not handle the 24 hours photperiod well.
would have to confirm with Dave on that one
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24 hour photo periods were/are commonly used by folks who use CAULERPA species. More notably, grape caulerpa. The truth of the matter is that ANY caulerpa (and some other macros) can go "sexual" and release spores into your system which would cause major catastrophe with water conditions. There are plenty of pictures of "milky" tanks on the web to see. I don't think Chaeto goes "sexual" though... I've not given it the chance to, but hear that it just....doesn't.
By keeping the lights on 24/7, you break the "dark phase" of photosynthesis and therefore trick the caulerpa (or other algae) into a dormant stage of sorts. This keeps it from reproducing sexually and instead encourages vigorous growth in mass, which you then harvest...and POOF... nutrient export. The dark phase or Calvin Cycle is when the conversion of sugars into ATP occurs. The ATP and Oxygen is used up during cellular respiration. This cycle is continuous in the algae during the "Dark Phase". By robbing the macro of that dark phase, you are prohibiting it from using its chemical energy for reproduction purposes.
By the way... you can still have a system run 24/7 and have ANY change in water or other "environmental" quality and trigger a sexual event in macro algae...it just happens.
Much like when you brought home those first snails, acclimated them..and they immediately spawned... stress, in ANY living creature, can cause sexual activity. It makes sense right? If you/an organism thought it was going to die...it would want to pass on its genetics first.
in the research i have done, it seems that the best way to prevent Caulerpa from going sexual is to prune it regularly.
it seems that the lighting is mostly anecdotal.. in that people state the following.
i had my Caulerpa going sexual on a 12/12 lighting cycle, then i switch to 24h and prune it regularly and it has never happen since.
i also read people state that they have been on a 12/12 cycle, and prune regularly and have never had a problem. and i have not seen anyone state that they are on a 24 hour period, with NO pruning and not have a problem
the common factor here is that if you prune it, it is MUCH less likely to go sexual regardless of the photo period.
the thing with the 24 hour cycle, can it really be that productive it it doesn't get to complete its process of metabolising the sugars made from photosynthesis.
and regarding stress based spawning i thought this was limited to protists and micro animals. in that other life will reproduce when conditions are good, and the protists and rotifers type things (yes, another technical term ) would drop cysts to wait out the bad conditions. this would lend to the fact that micro algaes would not specifically spawn when "stressed".
i know i have read people say that there Caulepra will spawn with stresses like water changes, but I'm leaning towards the fact that its something else that kicks in, and the spawning its its more of a coincidence than a "stress thing".
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here is an interestign psot brom Bob Fenner that seems to suppor this so a degree, althoguh hes not very vocal
Quote:
Green seaweed research questions (and useful, scientific input!)
Hi Bob,
I found your address at the WetWeb site and thought I'd contact you
directly. Hope you don't mind.
<Not at all>
I'm a bio professor/researcher who studies the reproductive behavior
of tropical green algae in their natural environments (Halimeda,
Caulerpa, Penicillus, etc). I notice a fair number of posts to aquarium
sites that have to do with "green clouds", "white" or "dying seaweeds",
etc. and recognize (as you do) that most of this relates to the sexual
reproduction of these seaweeds... a 24 hour conversion from sterile to
fertile condition, followed by explosive gamete release at dawn and
immediate death of the "parent".
<Yes.>
My research explores the consequences of these reproductive events on
coral reefs (mostly Caribbean, though I'm currently on sabbatical in
Guam). I'm particularly interested in what induces a seaweed to become
fertile, since we often find hundred to thousands of algae on a reef (but
never all of them) becoming simultaneously fertile... not only is the
ensuing bout of sex the next morning a spectacular visual phenominon..
the subsequent death of so many "adult" seaweeds has important
ecological implications for the reef community as a whole.
<Agreed>
I notice from various posts within the aquarium trade that lights,
chemistry, temperature, stress, etc, etc, are implicated in the onset or
prevention of reproduction by green seaweeds in aquaria. Do you know of
any formal treatment of this idea...
<No... unfortunately seem to be entirely anecdotal accounts... of "stress", change that bring on these events.>
or is it just a hodgepodge of
observations thrown out over time? I notice you reference "24 h"
lighting as a preventative and I've seen reference to blue lights, or
non-blue lights (can't remember which) having similar effects. If you're
interested, I'd love to pick your brain about this... or you can sic me
on someone else.
<Very glad to be of assistance.>
If interested, you can also learn more about my research on seaweeds by
visiting: http://lclark.edu/~clifton/Algae.html
<Thank you much for this reference. Will post to our sites (WetWebMedia)for hobbyist perusal>
Thanks for your time... I hope to hear back from you.
Ken Clifton
<Sorry for the delay in response. Have been on a liveaboard... in the Bahamas. Be chatting, Bob Fenner>
1. the calvin cycle "dark cycle" occurs all the time. if it did not then the algae would die.
2. algae will spawn due to stress, caulerpa is no exception
3. pruning is the best way to defer spawning, with caulerpa
4. chaeto goes sexual regularly, it is just not noticed. caulerpa is polysiphionus and is dumbed down effectivly a few big cells, so when it goes reproductive is goes all the way and the whole organism switches to reproductive and then spawns. While chaeto, being multi cellular simply reproduces in little bits one cell at a time (or multiple cells throughout the 100's to 10000's of cells that make up the plant) that and it is not taxoc to the reef like caulerpas chemicals are.
5. some algaes make the cycsts too!
6. and as with all organisms the time of reproduction may have no reason associated with it. though events can be commonly assocated with tidal events, and other natural events in the ocean.
7. why do we really need caulerpa anyways? there are better choices for your reefs and local ecosystems to be using a dastardly invasive species that is not reef safe
__________________ Adam J
you would think with a degree and professional career i could actually spell words correctly. sory.
i wish it could be dissemenated to the general public along with 100's of other things, that the "dark cycle" is a old unused term that is no longer viable.
props to david for using "calvin cycle"
__________________ Adam J
you would think with a degree and professional career i could actually spell words correctly. sory.
the one thing you didnt get to was the whole lighting debate.
i assumed (and you confirmed) that pruning is probably the best way to control the spawning. i know you said there are better options other than caulerpa, but that point aside (but taken) do you believe the lighting period has an effect on it? if so is it major or minor in your opinion
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in that lighting period influences when it reproduces?
i would suggest that the 24hr photo period, would delay reproduction since: conditions are optimal for the plant, eg great light, and great chemical conditions for growth.
and since its a fairly all or nothing reproductive approach for caulerpa, this makes some sense,
but at some point it will go sexual in the 24hr photoperiod no matter how good conditions are, you can not cheat nature forever
(it may not in your tank where it has sat for XXXX time period, but chances are that it may if you were to repeat that time fram again)
__________________ Adam J
you would think with a degree and professional career i could actually spell words correctly. sory.
Hey Rob, sorry I re-posted in the other thread. I must have been skimming, cause I didn't catch the thread split at first.
So let me get this straight, does this mean that if I get my wife good and stressed-out... NEVERMIND...rofl
That was the reason I was told to go to a 24 hour photoperiod. I started my refugium with Caulerpa, about three different species, and it was going sexual and spreading. I forgot about that. It did seem to help switching to a 24 hour photoperiod. But, it helped more when I not only pruned the Caulerpa, but also when I added the Chaeto. If I had it to do over, I would only us the Chaeto.
Most feel that it is NOT good to mix species of Macro in a closed system. It is thought that the differing macro will actually compete with each other and could cause a chemical warfare of sorts. I use caulerpa ONLY because I have a "dual use" in mind. I use it for nutrient export AND as hitching posts for my seahorses.
I used Chaeto in my fuge and put some in the pony display before having access to caulerpa. However, seahorses are NOT brilliant and whilst hunting pods and mysid, they'd often get tangled up in the brillo pad and I'd have to help them out. I ditched the Chaeto and use it only in my new pod farming tanks.
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) would drop cysts to wait out the bad conditions. this would lend to the fact that micro algaes would not specifically spawn when "stressed". 