Help! Mantis shrimp molting

Perpetual Novice

Active Member
View Badges
Joined
May 16, 2019
Messages
423
Reaction score
335
Rating - 0%
0   0   0
I just added a bunch of new rock, inverts, and macroalgae to my tank with a peacock mantis shrimp. I was working and rearranging things for at least an hour. Then again the following day. A giant hermit crab I rather like fell into the mantis burrow but the mantis never attacked. So I spent 15 minutes trying to fit tweezers into the burrow to remove the hermit. That eventually scared the mantis out of the burrow where he frantically swam around the tank. All this commotion and stress and invasion of his burrow happened within the span of 24 hours.

I just put the lid back on the tank an hour ago I just looked in his burrow and saw what appeared to be a mangled smasher appendage and a gimpy eye. I thought I had injured it! But then I noticed the eye was actually shedding a layer so I’m pretty sure my mantis is suddenly molting.

I’ve heard mantis can molt from stress. I’ve also heard molting can be lethal if not handled properly.

What do I do?? How bad is it? Did I just doom my mantis by forcing it to molt at the wrong time??!
 

Bhor217

Active Member
View Badges
Joined
Feb 11, 2019
Messages
294
Reaction score
519
Location
Chicago, IL
Rating - 0%
0   0   0
Molts are tough on animals in general, and stress molts are def not ideal. If the mantis actually is molting, you should turn off all the lights in his tank, and def don’t disturb him. It is regular behavior for them to almost completely close off their dens using rocks so that they are not disturbed during their molt as it is when they are most vulnerable.

Molts are completely natural and is how they grow.

Edit: you should not put anything in the tank you will be unhappy to lose.

Unfortunately, there is nothing you can do but wait and watch. If it is molting , and survives, once it is done, it will start to be more active and come out of its den, but will still be a bit “slow” as their exterior hardens. My mantis refused food right before he molted.

Just a tip, you should never disturb a mantis in their den, that is their safe place, and if you continue to poke and prod in there, it will not be viewed as a safe place anymore.

If you have set your mantis up for success, it hopefully will come out unscathed, but all you can do is keep your fingers crossed.
 
Last edited:
OP
OP
Perpetual Novice

Perpetual Novice

Active Member
View Badges
Joined
May 16, 2019
Messages
423
Reaction score
335
Rating - 0%
0   0   0
Molts are tough on animals in general, and stress molts are def not ideal. If the mantis actually is molting, you should turn off all the lights in his tank, and def don’t disturb him. It is regular behavior for them to almost completely close off their dens using rocks so that they are not disturbed during their molt as it is when they are most vulnerable.

Molts are completely natural and is how they grow.

Edit: you should not put anything in the tank you will be unhappy to lose.

Unfortunately, there is nothing you can do but wait and watch. If it is molting , and survives, once it is done, it will start to be more active and come out of its den, but will still be a bit “slow” as their exterior hardens. My mantis refused food right before he molted.

Just a tip, you should never disturb a mantis in their den, that is their safe place, and if you continue to poke and prod in there, it will not be viewed as a safe place anymore.

If you have set your mantis up for success, it hopefully will come out unscathed, but all you can do is keep your fingers crossed.
About how long will it take to molt. The first thing I did right before I posted this was tale a rock and cover his den. I also turned off the lights. Now how long do I wait to see if he moves the rock?
 

Bhor217

Active Member
View Badges
Joined
Feb 11, 2019
Messages
294
Reaction score
519
Location
Chicago, IL
Rating - 0%
0   0   0
Let nature take its course, no need to try to barricade the den for the shrimp, I was just more mentioning it is their regular behavior before molting.

A source at my LFS who I trust very much (has 8 different type of mantids at home) said it should take no more than 3 day, and can happen in as little as a day.

My advice is to avoid temptation and leave it alone. If no movement in 5 days or a week, check water
Parameters, because you may have a dead mantis.

Sometimes doing nothing is very hard, I know from experience

I was very worried about my mantis’ first Molt, but i listened to advice and turned the lights off (and even put a towel over tank) and my mantis came out looking great.

Good luck!
 

Hemmdog

10K Club member
View Badges
Joined
Dec 9, 2018
Messages
11,681
Reaction score
44,773
Location
Silicon Valley, CA
Rating - 0%
0   0   0
Let nature take its course, no need to try to barricade the den for the shrimp, I was just more mentioning it is their regular behavior before molting.

A source at my LFS who I trust very much (has 8 different type of mantids at home) said it should take no more than 3 day, and can happen in as little as a day.

My advice is to avoid temptation and leave it alone. If no movement in 5 days or a week, check water
Parameters, because you may have a dead mantis.

Sometimes doing nothing is very hard, I know from experience

I was very worried about my mantis’ first Molt, but i listened to advice and turned the lights off (and even put a towel over tank) and my mantis came out looking great.

Good luck!
Great advice, thanks for sharing.
 
OP
OP
Perpetual Novice

Perpetual Novice

Active Member
View Badges
Joined
May 16, 2019
Messages
423
Reaction score
335
Rating - 0%
0   0   0
Let nature take its course, no need to try to barricade the den for the shrimp, I was just more mentioning it is their regular behavior before molting.

A source at my LFS who I trust very much (has 8 different type of mantids at home) said it should take no more than 3 day, and can happen in as little as a day.

My advice is to avoid temptation and leave it alone. If no movement in 5 days or a week, check water
Parameters, because you may have a dead mantis.

Sometimes doing nothing is very hard, I know from experience

I was very worried about my mantis’ first Molt, but i listened to advice and turned the lights off (and even put a towel over tank) and my mantis came out looking great.

Good luck!

I know iodine can initiate a molt prematurely. This all happened right after I added a lot of red feeder algae to the tank as decoration. I know iodine often appears red. Is it possible that I introduced a lot of iodine to the tank by adding the algae? I ordered it from liveaquaria along with a bunch of hermits and snails. I have also added a couple of fish and urchins in the last couple weeks. I’ve also been feeding home live crayfish a lot recently Is there any kind of livestock that would bring iodine into the tank?

I’m also worried about water quality since I usually clean up after the mantis. But now I can’t touch the tank and I know there are pieces of crayfish floating around and decomposing. My impulse is to run carbon and phosphate absorbing media, also add a ph buffer, and finally add a little bit of calcium to help with molting. But I also know that changes in water chemistry are bad for molting.

Is there anything you can tell me about the above. And are any of those treatments advisable. For now I’m doing what you said and just waiting anxiously with the tank lights off.
 

Bhor217

Active Member
View Badges
Joined
Feb 11, 2019
Messages
294
Reaction score
519
Location
Chicago, IL
Rating - 0%
0   0   0
I am not familiar with red feeder algae so I cannot help on that.

I feed my mantis live crayfish, same as you, and I also feed littleneck clams and fresh shrimp as well. Having a variety of food like that helps. I feed 2x a week, recently switched to 3 days a week, but have noticed my mantis is not as interested in food when i add the extra day, and have gone back to feeding 2x a week.

From my understanding, inverts have a good amount of iodine in them, so continue to feed them to your mantis. I get fresh clams and shrimp from my asian market, just picked up about 20 clams for 10 dollars on sunday!

There seems to be a lot of contradicting information on the benefits/negatives of iodine. I follow the lead of the person i consider an expert on Mantis', who is a supporter of dosing a small amount of iodine.

I dose 1mL of iodine 2x per week. It is a smaller dose than is "recommended" but by using less, you do not run the risk of overdoing iodine. 1x on Wednesdays and 1x on Sunday after my weekly water change. (my tank volume is around 50 gallons when the sump volume is included)

My mantis molted within a week of me beginning to dose with iodine, and when i spoke to my trusted LFS source i mentioned above, he said that the dosing likely kick started the process. To be honest, my knowledge of iodine and how it works is limited, but I completely trust my guy Scott.

As for worrying about water quality, I completely understand it, but you are best off not altering your water by adding phosphate or other additives. You nailed it on the head when you said changes in water chemistry is bad for molting.

I know it is hard to think about, but you only have a few more days of inactivity left. Putting the towel on my tank not only helped black out the tank, but also blocked my view of it which helped keep my thoughts slightly diverted. :)

Just keep thinking good thoughts, and hopefully you will hear that familiar popping noise soon!
 
OP
OP
Perpetual Novice

Perpetual Novice

Active Member
View Badges
Joined
May 16, 2019
Messages
423
Reaction score
335
Rating - 0%
0   0   0
I am not familiar with red feeder algae so I cannot help on that.

I feed my mantis live crayfish, same as you, and I also feed littleneck clams and fresh shrimp as well. Having a variety of food like that helps. I feed 2x a week, recently switched to 3 days a week, but have noticed my mantis is not as interested in food when i add the extra day, and have gone back to feeding 2x a week.

From my understanding, inverts have a good amount of iodine in them, so continue to feed them to your mantis. I get fresh clams and shrimp from my asian market, just picked up about 20 clams for 10 dollars on sunday!

There seems to be a lot of contradicting information on the benefits/negatives of iodine. I follow the lead of the person i consider an expert on Mantis', who is a supporter of dosing a small amount of iodine.

I dose 1mL of iodine 2x per week. It is a smaller dose than is "recommended" but by using less, you do not run the risk of overdoing iodine. 1x on Wednesdays and 1x on Sunday after my weekly water change. (my tank volume is around 50 gallons when the sump volume is included)

My mantis molted within a week of me beginning to dose with iodine, and when i spoke to my trusted LFS source i mentioned above, he said that the dosing likely kick started the process. To be honest, my knowledge of iodine and how it works is limited, but I completely trust my guy Scott.

As for worrying about water quality, I completely understand it, but you are best off not altering your water by adding phosphate or other additives. You nailed it on the head when you said changes in water chemistry is bad for molting.

I know it is hard to think about, but you only have a few more days of inactivity left. Putting the towel on my tank not only helped black out the tank, but also blocked my view of it which helped keep my thoughts slightly diverted. :)

Just keep thinking good thoughts, and hopefully you will hear that familiar popping noise soon!

Got home today and the tank stank to high heaven. I moved the rock and saw that the mantis wasn’t moving and wasn’t pedaling his fins and was on his back. I pulled him out and he fell apart and smelled horrible. It seems he got halfway through molting before he died. Very sad day.
 

Terrorizer777

New Member
View Badges
Joined
Sep 26, 2021
Messages
11
Reaction score
0
Location
Guntown
Rating - 0%
0   0   0
I just added a bunch of new rock, inverts, and macroalgae to my tank with a peacock mantis shrimp. I was working and rearranging things for at least an hour. Then again the following day. A giant hermit crab I rather like fell into the mantis burrow but the mantis never attacked. So I spent 15 minutes trying to fit tweezers into the burrow to remove the hermit. That eventually scared the mantis out of the burrow where he frantically swam around the tank. All this commotion and stress and invasion of his burrow happened within the span of 24 hours.

I just put the lid back on the tank an hour ago I just looked in his burrow and saw what appeared to be a mangled smasher appendage and a gimpy eye. I thought I had injured it! But then I noticed the eye was actually shedding a layer so I’m pretty sure my mantis is suddenly molting.

I’ve heard mantis can molt from stress. I’ve also heard molting can be lethal if not handled properly.

What do I do?? How bad is it? Did I just doom my mantis by forcing it to molt at the wrong time??!
So question. Is curling up while sitting up a sign of molting? Because I’ve had my Caped spearing mantis shrimp for two weeks now and he hasn’t made a den yet. He’s started on it and made a temporary (I think) little crater in some rock. That is where he is curling up and just sitting at. But he keeps flattening out every now and again but doesn’t move from the crater. Is this normal or a sign because he can’t really block it off. And I do have a rock and old drift wood he has started a den in but never worked on again.
 

Rock solid aquascape: Does the weight of the rocks in your aquascape matter?

  • The weight of the rocks is a key factor.

    Votes: 10 8.6%
  • The weight of the rocks is one of many factors.

    Votes: 42 36.2%
  • The weight of the rocks is a minor factor.

    Votes: 35 30.2%
  • The weight of the rocks is not a factor.

    Votes: 28 24.1%
  • Other.

    Votes: 1 0.9%
Back
Top