Dwarf Crays dying

[milalic]

I have read the article regarding mexican dwarf crayfish in the Articles section. From the article the only thing that seems that I am not doing is the aragonite in the filter.

Is anyone aware of any plants that might be toxic to crays and not shrimp? The reason I am asking is that I have a well cycled tank that I keep snowballs and dwarf crays. The snowballs are thriving and multiplying while the crays are slowly dying.

My tank has a ph of 7, gh 5dkh, kh 3-5dkh. and the temp is 75F.
I keep mosses, different hygro, some crypts, java fern, cambomba and ludwigia in the tank.

I feed them a variety of foods which contain calcium. Do they need a highe amount of calcium?

Any advice/ideas/help greatly appreciated.


Thanks,
Pedro

[Mustafa]

They don't need anything special (such as "high calcium" food), nor do any other invertebrates need any special prepared food. Are you doing large enough, frequent water changes? Most problems with dying animals can be solved by feeding less and performing larger, more frequent water changes. That, of course, only works if the animals you got were in good health to begin with. If you you received unhealthy animals, then you can only sit tight and hope they survive.

By the way, the article you read does not necessarily apply to the cajun dwarfs. You do not need aragonite in your filter, especially not with your hard, alkaline texan water.

[CanadianCray]

I have read the article regarding mexican dwarf crayfish in the Articles section. From the article the only thing that seems that I am not doing is the aragonite in the filter.

Is anyone aware of any plants that might be toxic to crays and not shrimp? The reason I am asking is that I have a well cycled tank that I keep snowballs and dwarf crays. The snowballs are thriving and multiplying while the crays are slowly dying.

My tank has a ph of 7, gh 5dkh, kh 3-5dkh. and the temp is 75F.
I keep mosses, different hygro, some crypts, java fern, cambomba and ludwigia in the tank.

I feed them a variety of foods which contain calcium. Do they need a highe amount of calcium?

Any advice/ideas/help greatly appreciated.


Thanks,
Pedro

Crays do not require enriched foods. They seem to do best with shrimp pellets & frozen veggies. My mexicans are doing great in 78F water full of shells & limestone. They will absorb much of their minerals directly from the water.

However. I always recommend that people keep shrimp & crays seperate because shrimp can be carriers of diseases that will kill crays.

[milalic]

I still do not understand why they are dying. I do frequent water changes and feed them less like you say. First time i've heard that shrimp can carry disease that will kill crays. I would have thought that it would kill other shrimp as well and that have not happened in the tank.

I'll keep searching and see if I can find what is wrong.

Thanks

[Neonshrimp]

However. I always recommend that people keep shrimp & crays seperate because shrimp can be carriers of diseases that will kill crays.

This is the first time I have also heard about this. Could you please tell us or refer us to more information on this subject?

Thanks.

[CanadianCray]

I will look for the info on this. I just have too much stuff to look through LOL.

There are a number of pathogens shrimp can be carriers for but not be infected themselves. They can infect other crustaceans that are not immune to them (ie Crayfish). Its just like the crayfish plague that North American crayfish carry but are usually immune to. When they have been introduced to European & Australian crays the results were desasterous.

Im not saying this will always happen. I have seen it happen a few times & I like to be better safe than sorry.