Does Xenia release Iodine when it dies? Inverts beware?

[Perpetual Novice]

I've heard that some people go as far as to supplement iodine in their tanks to help their xenia flourish. I haven't been able to verify this theory (and believe me I've tried), but that seems to imply that xenia is a bio-accumulator of iodine.

And if thats true then...

Well, it probably wouldn't be a huge issue for depleting your reef's iodine levels. The Xenia's uptake of iodine will slow to match the water concentration as it decreases. Xenia just accumulates it. It doesn't necessarily absorb it all completely. Your next water change will bring a fresh supply of iodine anyway.

So there's the red flag. After every water change the xenia has more iodine at its disposal to increase its internal concentration or grow new polyps (or both... x10). Iodine is going into your tank with the new salt mix but never leaving with the dirty water since lots has been trapped in the xenia.

So now what happens if the xenia dies...We've all heard the stories of xenia one day deciding to all melt. then randomly growing back out of nowhere as much as a year later. Where does that trapped iodine go?

Bonus: what chemical element can trigger invertebrates with exoskeletons to molt prematurely?



A year ago I decided to transplant a large rock of pulsing xenia into my nano tank from one of my larger tanks. The xenia defiantly died and I shrugged. that nano tank was a species tank for a peacock mantis shrimp. Suddenly the shrimp closed its burrow and began molting. It never came out again and I removed a half molted corpse from the tank a week later.


I dont know what caused my healthy mantis to suddenly die but I have my suspicions. Anyone more knowledgable than me thank can shed some light on my concerns would be a godsend.

 

[Cory]

Interesting observation for sure

 

[ReefReadyYouTube]

You should test that theory.

 

[Perpetual Novice]

Interesting observation for sure

You should test that theory.

Ok I think I found something. Its not a scientific paper but it is an article that references studies that have been done.

"There are studies that show that Xenia does contain substantial iodine, and it is likely that it got it from the water column, but what good, if any, that iodine serves is unknown. In a recent publication, Ron Shimek showed that a wild specimen of Xenia sp. contained 350 ppm iodine on a wet basis and a captive specimen showed 270 ppm on a wet basis and 1350 ppm on a dry basis.29 Those values are as high as some of the macroalgae, and lend some support to the idea that Xenia accumulate iodine (and presumably have a use for it at such high accumulations)."

here is the link:

Chemistry And The Aquarium: Iodine in Marine Aquaria: Part I - Reefs.com

Chemistry And The Aquarium: Iodine in Marine Aquaria: Part I - This first article will cover what is known about iodine in the oceans, including what forms it takes and how toxic these forms are, what organisms use it, how they obtain it, and what they use it for. It will also detail some issues...

www.advancedaquarist.com

 

[ScottR]

I just want to add. Many people post their ICP tests here and one thing I’ve noticed is low iodine. Not sure that a typical salt mix will replenish iodine.

 

[Perpetual Novice]

I also learned more to help explain the death of my peacock mantis shrimp. When it died I was in the process of decorating my tank. Since mantis shrimps are messy eaters with a high bio-load, and since my tank is only 13.5 gallons, I decided to decorate it with things that would assist with nutrient uptake instead of conventional corals. I decided on macroalgae and xenia. Liveaquaria didn't have any red macroalgae in stock so I decided to substitute it with red feeder algae. Both the red algae and xenia were added and quickly died at the same time. The article sites that macroalgae contains some of the highest concentrations of iodine as well. So the two die-offs combined seem to be a likely candidate for causing the premature molting which killed my mantis shrimp.

 

[ScottR]

I also learned more to help explain the death of my peacock mantis shrimp. When it died I was in the process of decorating my tank. Since mantis shrimps are messy eaters with a high bio-load, and since my tank is only 13.5 gallons, I decided to decorate it with things that would assist with nutrient uptake instead of conventional corals. I decided on macroalgae and xenia. Liveaquaria didn't have any red macroalgae in stock so I decided to substitute it with red feeder algae. Both the red algae and xenia were added and quickly died at the same time. The article sites that macroalgae contains some of the highest concentrations of iodine as well. So the two die-offs combined seem to be a likely candidate for causing the premature molting which killed my mantis shrimp.

I dose iodine regularly to my tank. Have you tested your water to confirm that you have high iodine? This is the first I’ve come across of hearing iodine overdose. I highly doubt this theory. Many people add nori to their tanks to feed algae eaters. Nori is high in iodine. I’ve fed my tank nori many times and I can’t say that I have had an iodine overdose.

 

[Perpetual Novice]

I just want to add. Many people post their ICP tests here and one thing I’ve noticed is low iodine. Not sure that a typical salt mix will replenish iodine.

maybe not a significant source then. but when trying to research xenia's iodine content I inevitably came across lots of discussions about dosing Iodine with a common theme being that it was unnecessary because sufficient iodine enters the tank through water changes and feeding. regardless, for the bioaccumulation in xenia to occur its not necessary for iodine to exist in high concentration in the water. it would just accumulate more slowly.

 

[ScottR]

BTW, if you have Xenia dying, I’d be looking at salinity. Xenia is hard to kill. It’ll take salinity swings or temp swings to kill it.

 

[ScottR]

maybe not a significant source then. but when trying to research xenia's iodine content I inevitably came across lots of discussions about dosing Iodine with a common theme being that it was unnecessary because sufficient iodine enters the tank through water changes and feeding. regardless, for the bioaccumulation in xenia to occur its not necessary for iodine to exist in high concentration in the water. it would just accumulate more slowly.

Look through some of the ICP tests here. Almost all have low iodine. I’m just saying your hunch is probably off and I’d look elsewhere for your problems.

 

[Perpetual Novice]

I dose iodine regularly to my tank. Have you tested your water to confirm that you have high iodine? This is the first I’ve come across of hearing iodine overdose. I highly doubt this theory. Many people add nori to their tanks to feed algae eaters. Nori is high in iodine. I’ve fed my tank nori many times and I can’t say that I have had an iodine overdose.

I did not test Iodine. I only began considering iodine as the culprit after I had cleaned up the mess and done several water changes. but I don't think I can equate my dieoff with supplementing nori when feeding. the tank is only 13.5 gallons with a 5-inch sandbed and significant live rock. there was a lot of xenia and macroalgae added which died all at once.

 

[ScottR]

I did not test Iodine. I only began considering iodine as the culprit after I had cleaned up the mess and done several water changes. but I don't think I can equate my dieoff with supplementing nori when feeding. the tank is only 13.5 gallons with a 5-inch sandbed and significant live rock. there was a lot of xenia and macroalgae added which died all at once.

I can 100% guarantee that iodine is not the cause. I’d be checking lighting, salinity, temp before anything.

 

[Perpetual Novice]

BTW, if you have Xenia dying, I’d be looking at salinity. Xenia is hard to kill. It’ll take salinity swings or temp swings to kill it.

the xenia had just been transplanted from a different tank and the feeder alga is apparently ill-suited to survive in an aquarium.

 

[Perpetual Novice]

I can 100% guarantee that iodine is not the cause. I’d be checking lighting, salinity, temp before anything.

I got a new mantis after my tank recovered. same system and same rituals and upkeep with no issues and healthy regular molts.

 

[ScottR]

Can you post parameters? As in, freshly taken? Are you using a calibrated refractometer?

 

[Perpetual Novice]

Can you post parameters? As in, freshly taken? Are you using a calibrated refractometer?

yeah, will do. Also not saying that iodine is a definite culprit but I am still convinced it is a viable theory. mantis shrimps are hardy as they come and, even as inverts, are very tolerant of salinity swings and temperature fluctuations. they routinely survive in live rock collected from the ocean to thrive in aquariums inadvertently

 

[ScottR]

yeah, will do. Also not saying that iodine is a definite culprit but I am still convinced it is a viable theory. mantis shrimps are hardy as they come and, even as inverts, are very tolerant of salinity swings and temperature fluctuations. they routinely survive in live rock collected from the ocean to thrive in aquariums inadvertently

Very true. Mantis are very hardy. And I believe iodine wouldn’t even bother them. There is probably some other underlying issue. Don’t be afraid to check everything. I’ve personally had parameters jump out of whack and although I didn’t blame them, they were the cause. Salinity and temp are usually my go-to’s.

 

[Perpetual Novice]

hermits, a decorator crab, and two urchins also survived without issue until the pollution from the dead 6 inch mantis crashed the tank.

 

[Perpetual Novice]

Very true. Mantis are very hardy. And I believe iodine wouldn’t even bother them. There is probably some other underlying issue. Don’t be afraid to check everything. I’ve personally had parameters jump out of whack and although I didn’t blame them, they were the cause. Salinity and temp are usually my go-to’s.

iodine wouldn't poison them directly. but shrimp and stomatopods are known to be forced into premature molting when iodine is supplemented in aquariums. and that is frequently fatal, especially on larger specimens.

 

[ScottR]

iodine wouldn't poison them directly. but shrimp and stomatopods are known to be forced into premature molting when iodine is supplemented in aquariums. and that is frequently fatal, especially on larger specimens.

Your premise is that Xenia and macro died and released iodine. I’d be looking into why Xenia and macro died before anything else. Xenia is very hardy. That would be my worry more than anything else.