Is molting a good sign?

[pharazon]

Hello!

The first inhabitants to my new reef (fully cycled, of course) were four blue legged hermit crabs. They’ve been in the tank for about a week. Tonight I came home to a blue legged carcass laying on the sand bed. Of course my heart sank - it must’ve been something I did. Perhaps the tank is too new to support even the hardiest of life forms.

The wife, son and I immediately started searching the tank to determine which crab had croaked. I had intentionally picked out different shells so that we’d be able to keep track of them. We found the three smallest and assumed the largest had croaked. This didn’t make much sense to me, as I suspected one may have killed the largest to take its shell. But then we spotted it - the largest shell of the four. And, to my surprise, there was still a living crab inside of it! I realized what was left on the sand must’ve been a molt! I googled some pictures and confirmed that the eyeless corpse in my tank was indeed a molt. I was relieved to say the least!

I had read that elevated levels of iodine can cause crabs and shrimp to molt prematurely. Admittedly I don’t have a test kit for iodine, but I don’t think that’s the case here, as the tank is very new.

So, is molting a good sign? Bad sign? Not a sign of anything at all? I was just surprised to see it occur so quickly. Of course I may have just acquired the crab at time where it was nearing a molt anyway, but I was curious what others had to say about it.

I appreciate any feedback!

 

[DLHDesign]

Likely just a thing; not a sign. You'll find that there is a lot we (humans) don't know about marine life in the specifics, but in the general sense, there are some things that are common enough. Stress can trigger all sorts of behaviors that you normally wouldn't see in calmer times. Molting, spawning, jumping out of the tank - all of these can (and likely will) happen during difficult or tumultuous times. As moving into a new tank is a pretty major stress-inducer, it's not surprising to hear that a crab has molted.

A note on the iodine levels; just because you have a new tank doesn't mean that they are higher relative to the source you got them from. Different tanks have different levels of practically everything - which is why drip acclimation is a key part of every introduction (along with QT, of course <grin>). Even with a solid acclimation process, however, there are still going to be effects of moving from one environment to another. The trick is to learn which are normal - and which are a sign of something amiss. Such as by asking here - as you've done.