Quantcast

Does Halmidea release toxins?

Help Support Reef Frontiers:

The R/C Man

Well-known member
Joined
Feb 20, 2004
Messages
423
Location
Spokane WA
Hey everyone!

I noticed my Xenia are starting to look a little rough. My parameters are good. I do have have some halmidea that has turned white and has little green specs on the leaves. Does this macro release toxins when it dies? Thanks!
 

NaH2O

Well-known member
Joined
Jan 25, 2004
Messages
8,568
I had just done some reading on someone's issues with Halimeda species. I'll see if I can find the actual literature, but when Halimeda goes sexual - it all goes sexual. When macro algaes go sexual or die, they release not only toxins, but also all the nutrients they have absorbed. Macros have the ability to "leak" substances from itself (gelbstoff) - in order to make it easier to survive (i.e. compete for space).

Despite what may have triggered this on your halimeda, had you been performing any regular maintenance with it?
 

The R/C Man

Well-known member
Joined
Feb 20, 2004
Messages
423
Location
Spokane WA
Thanks Nikki!

I pulled most of it out and the xenia already seem to be recovering. Those xenia while a pain in the butt in some respects the are a great indicator of a problem in the tank. They are always the first to show.....
 

NaH2O

Well-known member
Joined
Jan 25, 2004
Messages
8,568
My apologies on the above post - I should have stated that gelbstoff is an example of things that can leak from macros.

Here is a little more information. I searched a little bit for toxin information on Halimeda, but came up short and it is getting late for me. Anyway, I'll give you what I did track down, and toss in some links.

The following quotes are from: Halimeda: The Cactus Algae

Halimeda go a step further to ward off aragonite-munching herbivores, such as parrotfish, by synthesizing noxious and potentially toxic secondary metabolites. The aptly named halimedatrial and halimedatetraacetate are diterpenoid compounds that appear to give Halimeda an extremely noxious taste and could prove toxic in large quantities (Paul and vanAlstyne 1988).
I also found it interesting that Halimeda have the ability for the cholorplasts to migrate deeper in the plant at night. This trick allows the algae to thrive by keeping "night time" critters like lettuce slugs that utilize the cholorplasts from munching on the plant.

Regarding the algae reproduction.....When Halimeda reproduce, the whole plant becomes reproductive at once....they are called holocarpic. Prior to the algae releasing its gametes....it turns pale white and has dark green dots (the gametangia).

Halimeda's sexual reproduction is similar, 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.
Here is another link - that shows a chart of the life cycle Halimeda Ecosystems

Recent observations have shown that sexual reproduction in Halimeda plants is to some extent synchronised (Clifton 1997, Hay 1997). Many individuals in a population may become fertile within a period of only a few days, and sometimes on the same day. Synchrony can be so exact that fertility events have been observed to occur simultaneously in the field and in a laboratory aquarium (Drew and Abel, 1988).

Eeek! Sorry for the length. Hope you find this informative!
 

The R/C Man

Well-known member
Joined
Feb 20, 2004
Messages
423
Location
Spokane WA
Thanks for the info Nikki!
I ended up pulling the rest of the halmidea and will be performing a water change tomorrow.... Just to be safe...
 

The R/C Man

Well-known member
Joined
Feb 20, 2004
Messages
423
Location
Spokane WA
Yes! I usually run it for 14days then pull it for a few and run it again. I just pulled it last night incase that was the problem... All my corals including my xenia seem happy today.. :)
 
Your email address will not be publicly visible. We will only use it to contact you to confirm your post.
Top