Molting Emerald Crabs SCHOOL PROJECT

[Dogshowgrl]

Good afternoon!

I work at a school and I am helping a student with a project. We are trying to induce molting of Emerald Crabs. These crabs with only be studied for 6 weeks ( or 2 molts which ever comes first) and then place in my 125 gallon I have already set up at home, for the rest of their time on earth.

We are measuring Iodine with a Red Sea test kit, I know no test kit is perfect, but it will get us enough of the information we are needing.

I am looking for a dosing amount for our test group. We are using Red Sea Coral Pro salt @ 1.025 according to our refractometer. I know most of you are doing a low level to make sure everything in your tanks are molting properly, but where can I find the information on toxic levels for short term and long term? We need to stay clear of them. What are your levels and how often are you seeing molts? Are you using a labeled product, like Coral Colors or Kents, or are you using something else?

Thank you for your input!!

 

[Calappidae]

Iodine isn't really that important as far as maintence required (as you stated, an overdose is toxic so most people avoid the buffers). It really is an ignorable parameter even for advanced reef setups.

There should be a natural level of sufficent iodine in your salt mix alone. Just doing a water change with your salt is already managing your iodine. If your salt is good, then your iodine is probably where it needs to be.

Beside, iodine doesn't trigger a molt, it only helps the development of a new exoskeleton grow in place. Triggering the molt would depend on varies factures such as food comsumption. You could probably get 2 successful molts in a month, but since emeralds are nocturnal and hide for protection during this delicate time, the odds of seeing the crab doing it are slim to none.. you may see the shell laying around however if that's all you're looking for.

 

[Dogshowgrl]

Thanks for the quick reply. Yes, we are just looking for the remaining shell. We have already gotten small emeralds hoping for quick growth from them. I guess "triggering" is poor word choice. I know the salt will have Iodine at 0.06 theoretically (at 1.023 based on packaging) and that should be sufficient, but if we can speed growth of the shell and with open buffet for food we should have some faster "success" ( I use the word success loosely, I am aware this is not ideal for long term care of them but for this experiment 2 molts is the goal of success). Should we use a lower quality salt and increase Iodine levels with dosing in the test group? We have to have higher levels in the test group than in the control group. We are testing the Iodine as our independent variable, if we are not able to increase the iodine due to high enough levels in the salt we need to choose another salt. Water changes will not be based on maintaining iodine levels but on keeping all levels withing safe living limits. If they stay within normal parameters, then we hope not to do any water changes. (No, this is not how I keep my tank at home I promise.)

 

[jraker]

those crabs will get lost in the 125. i can barely find mine in my 36

 

[Calappidae]

It's really hard to explain, but the salt mix you're setting the aquarium up has a stabilized ammount of iodine constant in it, and the iodine remains at a steady parameter so long as your other parameters stay in check (Example, if your calcium, alk, and mag are all good, usually the ph is stable as well, and vice versa)

If the project is to try and pinpoint whether or not crabs do benefit from iodine, it's a very difficult thing to get accurate results from since, like you've said, the age of the crab, as well as the food supply and generally the crab's health condition (this is a big one, if the crab is stressed out it can trigger a premature molt.. losing limbs may rush one as well. This is why sometimes they molt in the bag. Sometimes coinhabitant aggression will also trigger this if one crab bullies the other.). There are several variables.

I understand what the long term conditions will be, but for the project itself it's kinda tricky to manage something that manages itself (iodine, if your salt is good your iodine is too.. 1.019 and 1.025 doesn't change iodine much.).

I'm not a chemist (my tutors can confirm that.. lol a saltwater hobbyiest with chemistry tutors, the irony..) so I may be missing some kind of property relavent to iodine particularly, but to my knowledge, not too many people ever recommend even looking at iodine for the sake of not wanting to touch it. (People recommend NOT doing anything for it.)

 

[JamesHolt]

If you want them to molt/grow faster target feed them.. I feed my emeralds so they will behave..
Just use a syring/turkey baster with some mysis in it, the first few times they may run from it but squirt the mysis at them anyway..

https://www.youtube.com/watch?v=RD_WaGglSis

older video of me feeding mine...

 

[Dogshowgrl]

Thanks! They are feed and feed and the class loves them.