Petshrimp.com Discussion Forum

that is not completely true. There are many examples where inbreeding has no obvious negative results. 'The only important thing is the genes. Inbreeding only gives a individuum a higher chance of having some defects in both copies of its genes. If one selects for these genes to be ok, when inbreeding you can even get a more healthy strain. Of course that is not an easy thing to do. But in general I would not say that inbreeding always has to have negative effects.

I should have said that I meant all types of organisms can suffer from inbreeding,it is easy to think that more primitive ones are less afected by in breeding .

You can select for strong individuals even when inbreeding ,and it is always a question abot how much inbreeding you realy are doing ,hard to know with these types of animals as the don´t come with a pedigree and are usaly kept in groups.

The concept that you can inbreed untill you have removed all bad genes
is old and deply roted when it comes to pet breeding and have been shown
to have been wrong almost all the time.

Of course if no problems do apear, there is no need to worry.

I have never had any steril patzcuarensis. Maybe they were in form 2 when the females were ready or disturbed while mating etc.

I have got maybe six clutches in that tank with two orange males ,all where
infertile,I got one sucesfull clutch when a tiny chapalanus male manedged to clim over a tank divider witch to me would indicate that
thouse two orange males for some reason have not been fertile during this time,wich I guess also is a good illustration on what you wrote
about genetic purity in this group of species.I will not breed on from thouse
hybrides ,but it would be easy to breed them back to orange paztuarensis

bjar wrote:I think it is due to the orange males being steril.

I highly doubt it. It's most probably due to the water parameters and "environment." Hatchlings are extremely sensitive in both shrimp and crayfish. Even if the adults look ok, the hatchlings don't survive if things are not perfect. You can especially see that in newly established tanks...it takes some time for the tank to have the right environment for hatchlings to survive. The bacterial fauna in the tank *and* the filter has to establish itself, detritus has to accumulate (on which the hatchlings can feed)...the leaves in the tank has to break down and conlonized by bacteria. This last point is especially important as the micro-organisms that colonize and break down those leaves actually use up nitrate (and other nitrogen compounds) and thereby help you in your efforts to keep nitrates low.

Sterility of males would be the last thing I would be concerned about. By the way...I know *for a fact* that your males are not sterile, as the females would not be carrying around unfertilized eggs for any appreciable amount of time. Plus, those eggs would turn a different color (different from the dark green of fertilized eggs anyway) and start "rotting." So, the eggs are fertilized...it's just that your hatchlings are not surviving.

zwergkrebszuechter wrote: There is one more thing to watch: All mexican Cambarellus, including C. patzcuarensis, montezumae, zempoalensis and chapalanus were imported a long time ago and their origin cannot be traced back to the import without any gaps. As these species do interbreed, one cannot be completely sure, if they really are what we think and if they are genetically pure. Maybe all mexican Cambarellus in the hobby including the oranges are hybrids. If they are even real species and not just location types! The differences are few and maybe they get restructured when there is a review.

This is a *very* important point. I've been thinking the same for a few years now. Unless we have wild caught specimen available with *exact* data about their origin, we won't ever know what exactly went into creating domestically bred strains of crayfish (and shrimp!). I hope this will change in the future...I for sure will record where I caught my animals once I start going on collecting trips.

zwergkrebszuechter wrote:
Maybe all mexican Cambarellus in the hobby including the oranges are hybrids. If they are even real species and not just location types! The differences are few and maybe they get restructured when there is a review.

It looks like my PhD research is going to focus on exactly this: a review of the genus using genetics rather than morphology. The last review of the genus was back in 1983 .

I expect that there will be some restructuring when genetic traits are compared against morphological ones.

YuccaPatrol wrote:

zwergkrebszuechter wrote:
Maybe all mexican Cambarellus in the hobby including the oranges are hybrids. If they are even real species and not just location types! The differences are few and maybe they get restructured when there is a review.

It looks like my PhD research is going to focus on exactly this: a review of the genus using genetics rather than morphology. The last review of the genus was back in 1983 .

I expect that there will be some restructuring when genetic traits are compared against morphological ones.

I think so too. Did you find any way to get Mexican ones yet?

It's most probably due to the water parameters and "environment." Hatchlings are extremely sensitive in both shrimp and crayfish. Even if the adults look ok, the hatchlings don't survive if things are not perfect. You can especially see that in newly established tanks...

I had a newly established tank when I got my cherry shrimp. Some of the adults disappeared, most likely eaten by the apple snails after they died. The tank had an established sponge filter, live plants, and was completely cycled. I haven't seen any dead shrimp since, they have multiplied very well, and the new trio of C. patzcuarensis seem to be fine (though it's only been a week since they were introduced).
Somewhat surprisingly, the shrimp have long outlived the apple snails. I was expecting to be overrun with baby snails, but the 3 of them have died w/out producing any eggs.

Zwergkrebszuechter, what are your water parameters? What do you feed your C. patzcuarensis, how much, and how often? As successful as you are with the Cambarellus, you must have their requirements very well taken care of. Beautiful pictures too, BTW. How many generations did it take to produce those color morphs? Any advice you would share would be much appreciated. It is very frustrating to see something go wrong from lack of understanding, and the answers aren't usually obvious. It is even worse when living things suffer or die, when we try our best to keep them alive and well.

zwergkrebszuechter wrote: I think so too. Did you find any way to get Mexican ones yet?

I think I am going to travel to Mexico to collect as many of them as I can. Some specimens may be available from museum collections, but it is impossible to extract good quality DNA from anything that has been preserved in formaldehyde. But if I am lucky there may be some specimens preserved in alcohol that might be acceptable. But fresh specimens would be the best.

At this point, I will be focusing on the native US species that I can collect much easier before I begin planning trips to Mexico.

Sterility of males would be the last thing I would be concerned about. By the way...I know *for a fact* that your males are not sterile, as the females would not be carrying around unfertilized eggs for any appreciable amount of time. Plus, those eggs would turn a different color (different from the dark green of fertilized eggs anyway) and start "rotting." So, the eggs are fertilized...it's just that your hatchlings are not surviving

Well the eggs did rot away ,and they where not dark green ,but very
light in colour.I have raised two sucesfull clutches in that tank during that time the failed ones .One was the hybrid clutch I mentioned and one was
wild coloured from a femal I moved to that tank to breed with the orange males but witch turned out to be fertilised with a wild coloured
male I kept it with erlier.

YuccaPatrol wrote:

zwergkrebszuechter wrote: I think so too. Did you find any way to get Mexican ones yet?

I think I am going to travel to Mexico to collect as many of them as I can. Some specimens may be available from museum collections, but it is impossible to extract good quality DNA from anything that has been preserved in formaldehyde. But if I am lucky there may be some specimens preserved in alcohol that might be acceptable. But fresh specimens would be the best.

At this point, I will be focusing on the native US species that I can collect much easier before I begin planning trips to Mexico.

Be sure to get proper permits. It is supposedly only found in one lake called patzcuaro.

-Pedro

That is good advise milalic. You don't want to spend the trip finding great specimens and then find out you have to put them back If you do go, good hunting

milalic wrote:
Be sure to get proper permits. It is supposedly only found in one river called patzcuaro.

-Pedro

Cambarellus patzcuarensis is from lake Patzcuaro and vicinity, not a river called Patzcuaro.

milalic wrote:
Be sure to get proper permits. It is supposedly only found in one river called patzcuaro.

-Pedro

Yes, scientific collection permits will definitely be necessary. I'm probably 2 years away from a trip to Mexico and will concentrate on native US species first.

At this point in the US, invertebrates are generally forgotten when it comes to protection as threatened/endangered species, so permits for scientific collection are pretty easy to acquire.

YuccaPatrol wrote:
Yes, scientific collection permits will definitely be necessary. I'm probably 2 years away from a trip to Mexico and will concentrate on native US species first.

If you're going in 2 years I might just tag along if you don't mind. There are also quite a few interesting Macrobrachium species in Mexico that stay very small and have abbreviated or suppressed larval development (i.e. can be bred in freshwater!)

that sounds like a really exciting vacation... at least to me it does, i'm sure my gf wouldn't agree but then again she's not a fish/invert nut

Well, I hadn't considered such a thing, but a small group trip might be a really neat thing. It certainly would help to have a few more hands to carry buckets and pull nets through the water!

As I said, I am at least 2 years away from such a trip, but will definitely let people here know about it with plenty of advance warning. Such a trip will require coordination with Mexican biologists and scientific collection permits will be necessary for my research.