Algea/Plant ID

[Snelly40]

hey guys,
i just want to make sure this is in fact halimeda. Caulerpera (sp) scares me in case it goes sexual .
to me it looks like halimeda, which is calcium based. In reading i saw a few things i had questions on....
i have been reading Halimeda: The Cactus Algae by Kirby Adams - Reefkeeping.com but i value your expert opinions highly!

1)"The same study on the Great Barrier Reef showed that huge meadows of Halimeda produced up to 2 kg calcium carbonate per m2 every year. That means that a patch of Halimeda the size of an average living room would produce more than 100 pounds of aragonite in a single year"...

what does this mean?

2)"The calcification abilities of Halimeda make them useful as a barometer of calcium and alkalinity parameters in a closed system, but can also render them somewhat dangerous in a system where the calcium demand is already high. Rapidly growing masses of calcareous algae are good indicators that the amounts of available calcium and carbonate in the water are adequate for calcification, a critical consideration for the maintenance of stony corals, This indicates production and deposit of aragonite crystals and is as reliable as any calcium and alkalinity test "

so should i leave it, its doesnt spread like a normal algea? and People who see my tank like how it looks, and is this a good indicator that my my levels pretty good?


3) now this scares me..."Halimeda's sexual reproduction is similar to Caulerpa's, but with the added benefit of a known warning indicator. Hours before releasing gametes, the algae will turn pale white with dots of very dark green or almost black along the edges of the thalli. The dots are called gametangia and contain all of the contents of the living plant, concentrated in tiny capsules. This creation of the gametangia is called sporulation. Shortly thereafter, the gametes are released in a fashion similar to Caulerpa's. Plants that reproduce in this fashion, with the entire plant becoming reproductive, are said to be holocarpic. These sexual events have been blamed for sudden deaths of tank inhabitants, and the secondary metabolites of the algae are often fingered as the cause. While this is certainly possible, it seems more likely that fish and invertebrates succumb to oxygen deprivation during these gamete-releasing events. The entire content of large masses of algae is concentrated in millions of short-lived gametes, putting an incredible oxygen demand on the system. Under these circumstances, immediate partial water exchanges combined with increased aeration and protein skimming are called for"

now i am thinking i should take it out.... but then it says " This is a worst-case scenario, however, and most sexual reproduction occurs without the destruction of the entire system, or any ill effects at all. It has been suggested that a lack of pruning and a deficiency of iron lead to sporulation (Tullock 1997). Personal observations indicate regular pruning to be a deterrent to sporulation"

so should i just be pruning it back?

4) over all this site seems pretty high on this plant in closing it says " Halimeda's resistance to grazing and their tendency not to overrun and damage sessile invertebrates make them a far better choice as a decorative and functional alga than Caulerpa. Factor in their nutrient export capabilities and service as an alkalinity test and you have the perfect marine plant for the home aquarium!"

anyway, here are the pics....



-jason

[mps9506]

Your id is correct. I don't have any expereince in this going sexual so I can't chime in there. It is a useful indicator that you nutrient levels are right on. It is IME very easy to prune back and control unlike macros such as caluerpa.

[BigAl07]

I have some in my DT ( just appeared one day out of the blue) and have since bought a sprout of it and it's growing in my fuge.

[Snelly40]

thats what happened with me, it just appeared, then GREW really fast!

[Snelly40]

so everyone thinks this is ok to have?

[Witfull]

its fine to leave in, but watch your calcium levels,,,it sucks it in and binds it in its leaves. when they fall off and die the leaves appear to be fossilized.

[johnmaloney]

nice find. it is safe, problems with it going sexual and crashing tanks are exaggerated. I am not saying it is not something to watch out for, but don't let it keep you up at night.

[reefer4200]

i jus recently had this show up in my tank good to know about it!

[prow]

i have had it before in my DT. for the most part if your not into sps corals you got no worries, just trime it from time to time.
besides their Ca+ uptake watch for falling "leaves" that break off releasing all the stuff they contain. including toxins that are found on the top edges of the leaves. so another thing to think about is if you have any tangs or other algae eating fish. most know to stay away but not all, just FYI.

[johnmaloney]

the "toxins" aren't poisonous to anything, they simply taste bad to deter herbivores from eating them. they do take up calcium though, so make sure to dose calcium to keep it strong, something you have to do anyway if you have corals. halimeda is not in the caulerpa family, didn't know if that is what you meant in an earlier post.