Dwarf crays with shrimp?

frugalfish · Post by **frugalfish** » Fri Jul 08, 2005 2:03 pm

Can dwarf crays such as the Mexican Orange or C. shufeldtii coexist with small shrimp species such as neocaridina sp. etc. or is that just asking for trouble. I've read how the dwarf crays don't seem to harm small fish, but what about small shrimp species?

Post by **Mustafa** » Sat Jul 09, 2005 9:51 am

Yes, they can be kept with shrimp as long as the tank is large enough and there are only a few dwarf crayfish. In most situations there are no problems whatsoever. However, if the whole bottom of the tank is filled with dwarf crayfish, the shrimp will suffer since the crayfish will bother them every time the shrimp try to sit on the ground.

frugalfish · Post by **frugalfish** » Sat Jul 09, 2005 10:19 am

Great.

I wasn't quite sure of the agressiveness of the crays. So keep eveyone happy with no overcrowding, full bellies, and clean conditions and things should be good...simple enough.

Acsuth · Post by **Acsuth** » Thu Jul 28, 2005 2:26 pm

hey just my $.02 from my own experience -- I've always found my dwarf crays to be a little more aggressive than most of what I have read tells me. If you have a huge tank and tons of shrimp, you probably won't even notice....but when I had about 8 cherries in with two dwarf crays in a 10 gallon....even losing one sucked...I wound up losing three before I separated them(and yes the crays were hunting them -- I saw the attack and death first hand)....and they were all very well fed - so I just figured from then on if I value my shrimp, I'll keep them away from the crays. I'd be interested to hear anyone else's story about shrimp/cray cohabitation.

Janis · Post by **Janis** » Thu Jul 28, 2005 3:57 pm

I have some Mexican Dwarfs in the same tank as adult tiger shrimp and I haven't had any problems with shrimps being killed, but the crays definitely harass them. When I first put the shrimp in the tank they would spend most of their time on the ground, but now they have taken to living on the rocks and plants where the crays can't get them as easily. The crays tend to sneak up on them with their pinchers open and touch the shrimps until they swim away. I don't think they actually close their pinchers on them because I've never seen any damaged shrimp, but they get close enough that they definitely could.

I used to have pygmy cories (habrosus) in the tank and I had to move them because they were getting nipped fins. The ottos are fine though, they're a little quicker.

Janis

CanadianCray · Post by **CanadianCray** » Sun Jul 31, 2005 9:31 am

Hello Janis just wondering where you came across your Mexican crays & if you've had any luck breeding them???

amber2461 · Post by **amber2461** » Sun Jul 31, 2005 9:37 am

Where are you located at CanadianCray, if you don;t mind me asking.

CanadianCray · Post by **CanadianCray** » Sun Jul 31, 2005 9:57 am

I'm in Burlington, Ontario. Just west of Toronto.

Janis · Post by **Janis** » Mon Aug 01, 2005 11:35 am

Hi Craig,

The crays show up on Aquabid occasionally and shipping to Canada is possible if you're willing to pay for it, but I just went across the border and picked them up over there.

I just got mine recently so haven't had any babies yet, hopefully soon!

Janis

Acsuth · Post by **Acsuth** » Mon Aug 01, 2005 2:43 pm

Janis wrote:Hi Craig,

The crays show up on Aquabid occasionally and shipping to Canada is possible if you're willing to pay for it, but I just went across the border and picked them up over there.

I just got mine recently so haven't had any babies yet, hopefully soon!

Janis

How many pairs do you have?

Janis · Post by **Janis** » Wed Aug 03, 2005 7:33 pm

As of today I am down to one pair from three.

The females have been carrying eggs, but I don't think any have been fertilized because they seem to drop them after about a week. The problem that I'm having is that they keep dying right before or right after moulting. I just had a female die in the midst of moulting. I don't think her carapace separated properly. I wonder if it's my soft water. I can't seem to get the hardness up high enough, even though I've got coral gravel in the filter and I recently sprinkled some on the gravel. I can't think of what else might be wrong. I change 20% of the water once a week, they eat well and the tigers that are in there with them are moulting fine. Mustafa, you have soft water, do you add anything other than coral gravel to your cray tanks? Any suggestions would be greatly appreciated. Thanks!

Janis

Acsuth · Post by **Acsuth** » Thu Aug 04, 2005 3:32 am

to raise the ph you can add a small amount of baking soda -- don't add it directly to the tank, just to the waterchange water. If you have any fish in the same tank this could stress them so do small water changes to begin with to more slowly raise the ph. I also add a drop or two of iodine every week or two -- it is good for all invertebrates IMO...not exactly sure of what takes place, but I have seen first hand that it is good for shells and exoskeletons and it may help your molting problems. I get the Kent brand -- it says it's for marine aquaria, just don't use the amount it suggests -- only a couple drops or so each time you do water changes depending on what size tank you have.
Also -- what are you feeding them? Mine will nibble most everything, but they eat the best when I feed frozen food: brineshrimp or bloodworms.
note: I have never seen a female crayfish drop eggs before -- but I have seen a random unfertilized egg among fertile ones. The unfert. eggs are a solid white/milky color with no darkness, and the fertile ones are sort of a dark gray that get darker.
When I lived in Florida I had a problem with infertility and sudden shrimp deaths -- I know now that it must have been something in the tap water....you might want to try an experiment with purified water to see if that doesn't clear up the issue.

--Amanda

Janis · Post by **Janis** » Thu Aug 04, 2005 7:53 am

Thanks Amanda,

I have been feeding them flakes, algae wafers, spinach and bloodworms. I usually give them bloodworms every two or three days because they like those the best.

I think I have seen some fertilized eggs in with the unfertilized ones, but there are only a few and they seem to drop them. I had one female carry one egg around for over two weeks! The latest batch of eggs was bright orange (very strange) and she only kept those for about 5 days. Have you ever seen bright orange eggs? They were about the same colour as she is. The male that I have left is quite a bit smaller than the female and I wonder if there are problems with fertilization.

Janis

CanadianCray · Post by **CanadianCray** » Fri Aug 05, 2005 1:41 pm

The problems you seem to have with molts is prob. a product of a few different things. Crayfish like HARD water. The harder the better. They absorb the calcium & other minerals from the water after a molt to harden the exoskeleton. Also keep in mind crayfish in the wild eat mostly plant material. The spinach or frozen peas are GREAT for them but things like blood worms etc. are a little too high in fat. A great source of protien believe it or not is actually SOY or if you wanna stick with fish material shrimp pellets or frozen brine shrimp. Also when the cray molts are you leaving the old shell in there? You should be leaving it for about 4 days with no other food. They will eat most or all of the old shell & get essential minerals from it. Never feed fresh shrimp as they can cause desease.

Also keeping crays with shrimp is risky too cause shrimp can carry a desease that will infect other crustaceans & the crays have no defence.

Acsuth · Post by **Acsuth** » Fri Aug 05, 2005 4:56 pm

Janis wrote:Thanks Amanda,

I have been feeding them flakes, algae wafers, spinach and bloodworms. I usually give them bloodworms every two or three days because they like those the best.

I think I have seen some fertilized eggs in with the unfertilized ones, but there are only a few and they seem to drop them. I had one female carry one egg around for over two weeks! The latest batch of eggs was bright orange (very strange) and she only kept those for about 5 days. Have you ever seen bright orange eggs? They were about the same colour as she is. The male that I have left is quite a bit smaller than the female and I wonder if there are problems with fertilization.

Janis

No, I haven't ever seen bright orange eggs, I would suspect that they aren't fertile though...I'd love to see a photo of that. After hatching, the female will carry around the babies for a while which are orange..but that's the closest I've seen and I'm sure that's not what was going on with your cray or you'd have seen babies by now. I can tell you that I had fertility problems with all my fish and inverts(except for the snails) -- so I started using bottled water in my spawning tanks and my fertility levels went back to normal...I'd say the problem is with your water most likely.