Help! Molting = death

[Korzak]

Help! Every time one of my cherries molts, they die. I find an empty shell somewhere in the tank, and a dead shrimp as well.

Is there something wrong with my water that the shrimp can tolerate with a hard shell, but not a new one?

There is nothing in my tank but shrimp, plants, and some tiny snails.

[TitoC]

As I have understood so far, this is an aspecific symptom. The shrimp are just dying at their most vulnerable moment. There has to be an underlying cause for this.
Some people have described this domino effect too. I guess that one shrimp dies of rather benign reason (old age or something) but then rots away out of sight and produces ammonia. Other molters then succumb due to the ammonia and so on..
There could be a disease hitting them too, but I would first optimize the bio-filtration on the tank if I were you. To me, that seems to be the most plausible explanation.
Some time ago in different discussions, we were thinking about problems with water hardness or certain minerals running out in tanks on the long run, but I never got convinced about any of the theories... the threads should still be out here somewhere.
In rare cases you can also kill a molting shrimp by making big changes in the water just when he's molting, but that is probably not the case here?

[TitoC]

How is the situation now Korzak?
Could you find out what was causing the deaths?

[moaid]

aarrrgghh...just removed 2 molting death shrimp... a cherry & CRS...damn! can still see the skin peeling....no direct explaination on this it seems.. or a multuple of causes....

[Dungmvp]

I have lost so many CRS during berried and after molting, with the ones berried eggs I noticed they wanted to molt but couldn't so I think cause by big changes in water (sometimes I do 20% WC, sometimes 30%, not much but could make them molt).
With the ones dead after molting I think they died because they were weak, strong females after molting still have energy to swim away of bothering males. When I saw it about to die I wanted to help her by taking her away from bothering males so I moved her to safer place (still in the tank and took good care) but still dead. So why they were weak? If there were any diseases why didn't kill all of 100+ but just 1 or 2 females in a month? Then and last I think maybe after long period of berried their health decreased and molting would make them died.
Not sure though, just what I could think of.

[moaid]

maybe its just them in natural state...some are stronger..some are weaker...or at least maybe that is how i want it to be...

anyone can advise on anything that they use to help ur "little ones" molt??

[TitoC]

Water changes can trigger molting, but it is part of their normal physiology, so normally should be no problem. (In my tanks it also triggers, but they are not "killed" by it, even when I do upto 50% changes when moving tanks etc)

Another thing I was thinking about: do the shrimp have enough hiding places / substrates to hold on to when molting?
Often I see shrimp molting on vertical substrates and then hiding up in the plants, close to the surface.
If the tank is too bare, they might not find a good place to hold on and jump out the skin. And then afterwards they are easily exhausted by passing shrimp and horny males...

Recently I also saw some cannibalism in crystal shrimp (for the first time) in tank where I did not add food. The tail was nibbled on and there was nothing as far as I know in the tank that could have done this except shrimp. I found a dead one too after molting. So when there is not enough food, maybe the molters are preyed upon...:undecided

[silane]

To add beside the above..

Normally is bad water quality, that cause them to molt and die.

Then water parameter, maybe too soft or too hard, you can tell if they failed to molt or molt and cannot form shell.

[dxiong5]

: (
Woke up this morning to find three Tigers picking on a dead RCS next to a half-empty shell.

[magpie]

Whenever, I see a skeleton shell I will see a pale/delicate skin colour shrimp resting/hiding at the DW and stay there for quite long. After the stage of molting, the shrimps are vulnerable. Do create more hiding place in the tank for them to hide, and monitor whether do you still see a died shrimp after they molted.

[shrimpman5]

Sounds like you shrimps are having molting issues.

They are lack of Cholesterol. http://cat.inist.fr/?aModele=afficheN&cpsidt=17849368

Google "Phospholipid shrimp" you will find a lot more info regarding shrimp molting.

What kind of food do you feed your shrimps? Try give different food, so they get balanced diet. They are no different than human in terms of receiving nutritions. We eat different stuff (meat, diary prod, vegis and ...) everyday to get different nutritions, and same as animals like shrimps IMO.

[infopimp]

I've heard (and it may be already in this thread) that too much protein rich food (eg, frozen bloodworms) can cause molting problems.

[TitoC]

Sounds like you shrimps are having molting issues.

They are lack of Cholesterol. http://cat.inist.fr/?aModele=afficheN&cpsidt=17849368

Google "Phospholipid shrimp" you will find a lot more info regarding shrimp molting.

What kind of food do you feed your shrimps? Try give different food, so they get balanced diet. They are no different than human in terms of receiving nutritions. We eat different stuff (meat, diary prod, vegis and ...) everyday to get different nutritions, and same as animals like shrimps IMO.


The dietary requirements of penaeid shrimp are not the same as those of freshwater dwarf shrimp. Most research has been done on penaeids. What dwarf shrimp need is not known 100%. Most commercial diets have been tested by the companies but some could be incomplete. Feeding other food is a good idea, and I have noticed that dwarf shrimp indeed like some animal foods from time to time. Just as they eat molt skins, so can they use the cuticle of other crustacean or insect larvae to build their own skin...

[Obama]

This may sound morbid but i usually leave a dead shrimp to be eaten by its fellow shrimps. They will usually dispose of it within a day. Seems a good source of protein and whatever. i am sure it happens in the wild too.

[Breeder]

DONT do water change too much.
make the water clean by filter a lot better than change water.

[TitoC]

This may sound morbid but i usually leave a dead shrimp to be eaten by its fellow shrimps. They will usually dispose of it within a day. Seems a good source of protein and whatever. i am sure it happens in the wild too.


A few down sides / risks to this:
- decomposing animals will always produce some toxic waste (ammonia) with possible threats to the other shrimp. Depending on the aquarium and filter, this can be an issue or no problem at all.
- shrimp are messy eaters and can spread the tissues around, so although the body will disappear, this doesn't mean it is really "gone" in a clean way
- if present, parasites and other infectious diseases can spread to other hosts more easily
- if present, planaria will benefit from the corpse and multiply even more

On the side:
- I don't know, but MAYBE, the shrimp could develop an appetite for shrimp meat and attack freshly molted shrimp?
- I notice that crystal shrimp are not interested in corpses, only when they don't get enough other food they start to bite each other / scavenge
- C. multidentata are for sure scavengers when they are not fed a lot