Introducing: Cambarellus diminutus

YuccaPatrol · Post by **YuccaPatrol** » Sat Sep 30, 2006 8:20 pm

ToddnBecka wrote:. . . . I was wondering whether it would be wise to house different species of dwarf crayfish together, more specifically Mexican and North American species?

I'm trying to understand how crayfish react to different species, as opposed to conspecifics.

There was one study of interspecies competition between C. Shufeldtii, C. puer, and C. diminutus done in the 1960's. The results indicated that C. Shufeldtii was dominant over the other two species and suggested that they would be unable to live together for an sustained period of time. This matches another study that found that C. shufeldtii was extending its range at the expense of the other two species.

I don't think anyone really knows much more than these two 40+ year old studies have offered. My conservative tendency would be to keep related species separate. These crays do seem rather peaceful, living a more shrimp-like existence than your typical cray, but I also observe some minor conflicts that are almost always ended almost as soon as they begin.

Although they seem mostly peaceful with their own kind, they may not be so nice to other species that they would have to compete with.

Maybe someone here has kept C. shufeldtii with one of the Mexican species and can share their experience?

The Fisherman wrote:Wow, i'm impressed Yucca, you know your stuff!!

Hehe, just test me on pufferfish

I don't know 1/10 of what I would like to know, and don't know a darn thing about puffers!

And the truth is that biologists don't know much more about any of these than what they look like and a few locations where they have been collected in the past. The dwarf crays are a very neglected group when it comes to the available scientific knowledge. For the most part, biologists have preserved them in formaldehyde, given them a name, and then forgotten about them. So much more has been done with species of "commercial value".

edit: I am keeping these with the ghost shrimp that I collected from the same streams, and they don't seem to care one bit about the shrimp.

Post by **Mustafa** » Sat Sep 30, 2006 8:35 pm

YuccaPatrol wrote:edit: I am keeping these with the ghost shrimp that I collected from the same streams, and they don't seem to care one bit about the shrimp.

The shrimp *might* care about possible crayfish babies, though, especially after the babies molt, are soft and can barely move. So, just keep an eye on that. They might not touch them at all, but there is a possibility that they could. I have no idea about the behavior of P. kadiakensis, as I am not aware of anyone who has kept them and reported about their behavior, so you will be the first one to report back. We're counting on you.

YuccaPatrol · Post by **YuccaPatrol** » Sat Sep 30, 2006 8:44 pm

Oh my! I hadn't even considered that.

That piece of advice might be a real life-saver for the baby crays!

I'll make sure to remove the ghosts as soon as the first berried female is observed!

As soon as I can bag up some shrimp to be shipped off to a friend, I'll be consolidating my cherries into one main tank to create extra space for berried females and baby crays.

ToddnBecka · Post by **ToddnBecka** » Sat Sep 30, 2006 10:36 pm

Definitely better safe than sorry. I plan on setting up another 10 gallon for my dwarf crayfish when I see eggs, maybe sooner. Even if the cherry shrimp aren't a threat to the baby crayfish, they still outnumber them considerably, and competition for food would be in favor of the shrimp.
My wife said she saw one of the dwarf crayfish with a shrimp in its claws, though she didn't know whether the shrimp was dead or alive at the time. I wouldn't think too many shrimp would fall prey to the cray's, more likely it was a dead one?

YuccaPatrol · Post by **YuccaPatrol** » Mon Oct 02, 2006 4:00 am

I found one single female carrying a baby yesterday.

Of course, I have nothing to do with her success, but it is encouraging to see that a baby has survived being collected, transported, and acclimated to my tank.

milalic · Post by **milalic** » Mon Oct 02, 2006 5:15 am

Very nice...they must like the conditions in your tank

YuccaPatrol · Post by **YuccaPatrol** » Mon Oct 02, 2006 5:51 am

milalic wrote:Very nice...they must like the conditions in your tank

That's what encouraged me so much: my tank conditions must be suitable for that female to keep a baby for the past 10 days.

This is my first acidic tank, so I am having to learn as I go. So far, mixing 20% DI water with my tap water and filtering through peat is keeping the pH at 6.4, which is close enough to the 6.2 that I measured their stream water to be. I don't know what range of pH they can tolerate, but one paper I read stated that they were always found in more acidic conditons than C. shufeldtii.

I just cleared out a 10 gallon cherry shrimp tank so I can give some of them a little more room and make sure I have a backup tank in case something went wrong down the line. I had no idea how many cherries were really in there until I went to remove them.

milalic · Post by **milalic** » Mon Oct 02, 2006 7:54 am

That is great. I bet you have tons of cherries that you did not know about.
So you are using peat...interesting. I am trying the muriatric acid method as I believe I will have better control with it.

-Pedro

Neonshrimp · Post by **Neonshrimp** » Mon Oct 02, 2006 8:09 am

Hi Yucca, that is a wonderfule picture of a baby and parent

. So how many cherry shrimp did you find in your 10 gallon tank?

YuccaPatrol · Post by **YuccaPatrol** » Mon Oct 02, 2006 9:12 am

The peat is working so far, and I think it is good because it also re-creates the tannin-rich environment of the swampy stream where they live in the wild. I'm going to get a different type of peat today though, as I have been using the Jiffy peat pellets which actually have some fertilizer added.

I'm in the process of testing the Jiffy pellets to determine exactly how much fertilizer is in them and how long they need to soak to remove it all. It is not a lot, but it is worth knowing how much is in there, especially because I think they use ammonium nitrate which will contribute both ammonia and nitrate to the water.

I had about 75-100 adult or young adult cherries and twice that many babies in that 10 gallon tank. At the end I used a very small hard tube and air line tubing to suck up the last of the babies.

Newjohn · Post by **Newjohn** » Mon Oct 02, 2006 3:35 pm

YuccaPatrol
Nce Picture.
And Thank You for keeping us updated on your progress.

I will have to try the Peat Method, in my Acidic tanks.

Finaly, a Crayfish that we can keep with Acidic Shrimp.

John

FISH WORLD ERIE · Post by **FISH WORLD ERIE** » Mon Oct 02, 2006 4:14 pm

Great picture. Hopefully you will get these going in the hobby.

Jason

Post by **Mustafa** » Mon Oct 02, 2006 6:00 pm

Newjohn wrote: Finaly, a Crayfish that we can keep with Acidic Shrimp.

John

You can keep the C. shufeldtii in acidic water, too. They are very adaptable.

Newjohn · Post by **Newjohn** » Mon Oct 02, 2006 6:03 pm

Mustafa
Thank You for the information.
I am still having problems, with getting younge ones.
The Female has carried eggs 4 times and still no young can be found.

John

Terran · Post by **Terran** » Mon Oct 02, 2006 6:12 pm

NewJohn are you replying because you are keeping them in Acidic water with little success?

Cause I keep mine in water ph 7 or so and they muliply like crazy....I even get young ones a third the size of my adults that carry and give offspring...Even in a rather unkept tank that houses tons of guppies with hardly ever water changing it they still seem to be able to shell out plenty of offspring...

I couldnt imagine anyone having trouble with the Cajuns because they seemed soo hardy...

You got any ideas so far for what you think the probelm could be....