Two questions about shrimp

[leafyseadragon]

1. I have had my peppermint shrimp for three weeks now. In that time he has molted twice. I doubt any of my hermit crabs have molted more than once in 6 months. How often do shrimp molt?

2. I would like to have a cleaner shrimp in my 37 gal tank. Will it get along with the peppermint shrimp, or will they fight?

 

[reefrunner69]

1) A shrimp will mold every 3-4 weeks, if it is happening more often, it may be ridding itself of toxins in the water. Molting is very stressful on shrimp and molting that often will likely kill it. I wouldn't worry about it yet, it is not uncommon for them to molt almost as soon as they are moved and then get back on a normal shcedule, if the schedule continues though, you may need to look for a cause.

2) I think they will get along just fine

 

[leafyseadragon]

There should be no toxins in the water. The shrimp has been in the QT for three weeks now, I put a little Tech-I in the water this week. Other than the shrimp, rocks and sand, there is nothing else in the tank. I assume this means a negligible bio-load.

 

[reefrunner69]

There should be no toxins in the water

What you consider toxins and what the shrimp considers toxins are two totally different things For instance, the iodine you added to the water is not beneficial to shrimp, it is a poison, it does not aid in molting, it causes it. Shrimp will molt to remove iodine from their bodies. At this point, I would look as the iodine as the reason for the molt. You provide more than enough iodine through regular water changes and feedings.

 

[leafyseadragon]

reefrunner, now I'm confused!

A lot of web sites I have seen (like LiveAquaria) say peppermint shrimp require iodine for proper molting. So the iodine is a catalyst? I wish they had said so! 8O

 

[reefrunner69]

No need to be confused...I'm right, they're wrong

It has been popular belief for along time that iodine "aids" in the molting process, and in very small amounts (NSW levels of iodine are 6 parts per billion) this may be true, simply because once the iodine level in their tissue reaches an intolerable amount for the shrimp they molt. There is nothing wrong with NSW levels of iodine...but you add plenty to your system via water changes and feeding. I add no iodine to my system and my cleaner shrimp molts regularly. Iodine is an antiseptic, it is used to kill things

 

[f-dean]

iodine

this is true of iodine the only two things that really kill bacteria well are iodine and bleach

 

[reefrunner69]

Frank,

to AquariumAdvice.com!!!

You have a pm....

 

[noobtank]

that sounds about right...i think the first two weeks i had my peppermint shrimp he molted 2-3 times. he is doin just fine i've had my tank since jan 1 and i thnk he has only molted one time in the month of march

 

[24 hours? NE!]

I concur, mine molted a couple of times right away, then barely after that.

 

[Mrbill]

So dumb question, do you guys just leave the shells in there after a molt? A couple of my shrimp have molted recently and the shells just miraculously dissapeared...

 

[SquishyFish]

I have to respectfully disagree with reefrunner. I was told, as you are being told now, that Iodine is not nessisary...you can just do water changes and it will take care of its self. So I tested it. I quit dosing Loguls for one month. There was a dramatic difference in my Xenia...and other corals were showing signs of "fatigue" (for lack of a better word). I dose loguls on a regular basis, but in low amounts.

As far as the pep molting...it is my understanding that crabs and shrimp molt when they are growing (among other reasons). It has been my experience that the younger the crustatian, the more often it will molt. This makes sense if you are looking at it from a "growth" stand point. When do humans grow more, young or old? Obviously when we are young we grow the most. Same here. Young peps molt more because they are growing faster and therefore need to change "skins" more often.

I will agree with Reef on one point...no need to be confused...I'm right

 

[reefrunner69]

LOL, tell it to Bang Guy, that's where I learned what I know about iodine

 

[SquishyFish]

That cant be right...I taught Bang everything he knows!

 

[reefrunner69]

http://www.aquariumadvice.com/viewtopic.php?t=11658&highlight=iodine

http://www.aquariumadvice.com/viewtopic.php?t=18531&highlight=iodine

http://www.aquariumadvice.com/viewtopic.php?t=141&highlight=iodine

 

[steve-s]

Iodine in Marine Aquaria: Part I By Randy Holmes-Farley

Who uses iodine: Shrimp

As one moves up the food chain to more sophisticated organisms, data on their ability to take up iodine from the water column becomes very sparse. Shrimp are known to have a need for iodine to grow, but that is only known in terms of a dietary requirement. The shrimp, Penaeus chinensis O'sbeck, for example, grows optimally when the diet contains 0.003% iodine.56

Shrimp apparently incorporate substantial amounts of iodoorganics into their bodies. The shrimp Pandalus borealis, for example, incorporates between 0.04 and 2 ppm iodine as iodoorganic compounds depending on the particular body tissues examined. Their roe were somewhat higher, up to 4 ppm iodine as iodoorganic compounds.57 Shrimp shells and other parts can contain up to 17 ppm by dry weight iodine, the majority of which is iodoorganic compounds58, but the values are still far lower than for other inverts like macroalgae, sponges, or gorgonia.

Still, the amount contained says nothing about whether iodine is an important requirement. I could find no scientific studies that showed that shrimp need iodine from the water column, but neither could I find any that demonstrates that they do not.

Who uses iodine: soft corals such as Xenia

Surely, you say, there must be studies showing that Xenia and other soft corals need iodine from the water column? Well, I could find none. There may be studies that I could not find, and regardless of whether there are studies, iodine in the water column may or may not have a significant impact on these organisms. Nevertheless, there is no published basis (that I could find) for many of the claims about iodine.

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).

Of course, accumulating iodine from the tank somehow, and showing that supplemental inorganic iodine is beneficial are very different. I am in the planning stages of running experiments on the possible benefits of iodine supplementation to certain soft corals, but the technical challenges are significant (much more so than similar tests on macroalgae), and I’m not certain that they will be successful.

Also if interested...
Iodine in Reef Tanks 2: Effects on Macroalgae Growth By Randy Holmes-Farley

Cheers
Steve