Cristatus group egg problem - a legend?

[uwe]

Hi Sludge,

thank you for the data.

Azhael: "Uwe, a) may i ask why you still use the old clasification? b) You are free to do so"

Easy answer: a) because the animals don´t care. b) I never had a doubt about doing that.

Best Regards

Uwe

 

[vincent]

Hi Uwe hows this then, this year I crossed a male Italian Crested with a German Crested female, she laid 50 eggs and two of them went duff before they hatched I have just counted them now and at present I have 40 approx larvae feeding well and growing.So it's not very scientific with a one off, so I will do it again for the next two years and then when this years offspring are mature I will report whether they are sterile and the % of eggs that are duff before they hatch. They are all together in a heavily planted tank and I'm just going to let nature take it's course and see how many survive, normally I separate them into individual little tubs and feed them up individually when they get a bit of size on but I don't think I will get 40 out to maturity but it's so frustrating loosing the eggs before you get them to hatch I just thought I would see what happened though, just 2 of them duff was a vast improvement.:wink:

 

[uwe]

Hi Vincent,

thank you for this data. This is very interesting and actually exactly what I am looking for.

As Azhael emphasized that this crossing should experience the same sad rate of hatching, if you believe in the literature.

So my idea is to collect data, like yours, and compare that with the claims made in literature.

Best Regards

Uwe

 

[vincent]

Hi Vincent,

thank you for this data. This is very interesting and actually exactly what I am looking for.

As Azhael emphasized that this crossing should experience the same sad rate of hatching, if you believe in the literature.

So my idea is to collect data, like yours, and compare that with the claims made in literature.

Best Regards

Uwe

The thing is a few do die off as they grow and mature but to lose 50% BEFORE you start is very hard, I like other people have had total loses of eggs I got from other people but these crosses seem quite fit and healthy.I have lost a few as they start to nip each other ,but with plenty of food who knows how many will survive

 

[stavroske]

Hi Uwe hows this then, this year I crossed a male Italian Crested with a German Crested female, she laid 50 eggs and two of them went duff before they hatched I have just counted them now and at present I have 40 approx larvae feeding well and growing.So it's not very scientific with a one off, so I will do it again for the next two years and then when this years offspring are mature I will report whether they are sterile and the % of eggs that are duff before they hatch. They are all together in a heavily planted tank and I'm just going to let nature take it's course and see how many survive, normally I separate them into individual little tubs and feed them up individually when they get a bit of size on but I don't think I will get 40 out to maturity but it's so frustrating loosing the eggs before you get them to hatch I just thought I would see what happened though, just 2 of them duff was a vast improvement.:wink:

What are you going to do with the offspring ones they are mature? Are you going to sell them or try to create a new specie? I don't understand what the real improvement is about crossing them. Oke you might get a higher % of hatching eggs, but it's no longer a natural specie... If nature makes a mistake, most of the time it has it's own solution to deal with it. Fact that 50% of the eggs die and it's still the same for so many generations, might have a natural (good) reason which we are not yet aware of. Crossing them really doesn't look right to me...

regards,

Steven

 

[Azhael]

Couldn´t agree more, Steven.
Just because we don´t understand how the chomosomal situation of Triturus works, and how it benefits the species, it doesn´t mean it doesn´t. If the whole crested group has the same condition it means there must be a very good reason.
Also, to anyone allowing hybrids to be made, please keep record of this hybridisations, and if the resulting animals move hands, please notify the genetic background so that people know and can avoid further hybridisation. The last thing we need is to artificially loose genetic integrity (they do hybridize in nature but that´s their business).

 

[vincent]

Couldn´t agree more, Steven.
Just because we don´t understand how the chomosomal situation of Triturus works, and how it benefits the species, it doesn´t mean it doesn´t. If the whole crested group has the same condition it means there must be a very good reason.
Also, to anyone allowing hybrids to be made, please keep record of this hybridisations, and if the resulting animals move hands, please notify the genetic background so that people know and can avoid further hybridisation. The last thing we need is to artificially loose genetic integrity (they do hybridize in nature but that´s their business).

These will only be owned by me and possibly two other people who are interested in the experiment results. Interestingly one of my friends when he was touring Europe collecting newts etc [PRE 1980] said he came across hybrids showing characteristics of both local specie occurring naturally, He is at present trying to find the old photos. So what happens to these in the wild, do they walk around with a don't mate with me sign on them .No but if they then cross with pure stock do they improve viability of the stock, constant inbreeding with a small genetic pool causes major problems

 

[Neotenic_Jaymes]

Just to add more emphasis to the 50/50 natural abortion rate. I have experienced the 50/50 die off. A lot of other keepers I know have dealt with the 50/50 die off as well. I've witnessed known cases of almost 90% success rate in Itchyosaura. I have yet to breed any Lissotritons so I can't give any personal expierence about them. I'm sure the Triturus 50/50 natural abortion rate is not a legend. I respect the the new classifications as well.

 

[huug]

Hi guys,

I must be honest i havent read this whole topic.

I just want to add my experience on this matter.
I have been watching T.cristatus eggs in three different ponds two times over the last two weeks. What i noticed was that a lot of eggs were infertile. I did not count them, but i am sure it could have been at least about half of all eggs!

So this i saw in nature, and i notice the effect allso with my own triturus species, where my karelinii have a higher % (about 80% i guess) of bad eggs, half developing, where carnifex and dobro and marm clearly have less bad eggs.

 

[Azhael]

These will only be owned by me and possibly two other people who are interested in the experiment results. Interestingly one of my friends when he was touring Europe collecting newts etc [PRE 1980] said he came across hybrids showing characteristics of both local specie occurring naturally, He is at present trying to find the old photos. So what happens to these in the wild, do they walk around with a don't mate with me sign on them .No but if they then cross with pure stock do they improve viability of the stock, constant inbreeding with a small genetic pool causes major problems

There is a huge difference between naturally ocurring hybrids and captive-made ones.
It´s true that the cristatus complex often has some degree of genetic introgression in those areas where two species meet. This however happens naturally, within animals that naturally share the same habitat and therefore are adapted to it, and in many many cases the genetic introgression happened several generations before, the norm being same-species reproduction.
When you compare this to randomly mixing individuals of two species in captivity, there really is a big difference.

Anyway, no matter my point of view on the matter, you are free to do what you want, i just hope you keep track of all of them.

 

[uwe]

Hi Huug, hi James,

thanks for the reply. Interesting is also the observation in nature.

So I will keep you posted on my progress, but it may experience 50/50 rate too.Lets see.

Its always wise to challange literature, if there is not enough evidence around. But your responses and inputs convinced me.

See you

Uwe

 

[vincent]

Hi all I think we really need to see if crossing the same species but from totally different geographical locations ie a Russian Great Crested with a French one has any effect, unfortunately Great Crested are totally protected over here so it will probably have to be done by you guys in mainland Europe.I know they are not newts but I have some bombina varigata that are from a group first bred in the 1970s' the owner every two years tries to pick up one or two individuals from other people to maintain genetic viability to keep them ticking over .Now I'am nearly 50 yrs old and there are areas I know of that contained amphibians of all sorts they are now housing estates and football pitches, filled in , behind my house was a large pond full of toads and newts even GCN''s I told the authorities and basically they told me to p**** *ff its now a by-pass we don't know how often newts migrated between different ponds or how eggs were transferred from ponds accidently to keep viability. We don't have a chance now as we cant turn the clock back but it would be good to try and ease the egg problem to try perhaps with a new blood line introduced every couple of years to keep your stock healthy how many of us have bred from a pair, only to use the offspring as our breeding stock never introducing fresh blood.Cheers.:happy:

 

[uwe]

Hi Vincent,

I think that the animals and species have survived for several thousand years now without interfering by man (as cross-breeding would be) and we should do it the same way in the future.

I agree that most animals are extinct by destruction of habitat. This should be challanged.

See you

Uwe

 

[JM29]

Hello.

My reaction may be a bit late, but this topic sounds like a very old story.

I think the joined article answers definitively this question.

 

[uwe]

Hi,

thank you for the full article.

I am just curios if the data could be proven, which is not too difficult.

Best Regards

Uwe

 

[JM29]

Well, it depends on what you consider proven.

These chromosomic peculiarities have been studied mainly between 1970 and 1995, on T. cristatus (4 subspecies at that time, which are now recognised as true species) and T. marmoratus (which was not yet split in marmoratus and pygmaeus). See the summary in attached for more details.

Now, If you really want to check if all Triturus populations have this heteromorphism implying 50% embryo mortality, it might be as difficult as proving that all crows are black...

Sincerely yours,
JM

 

[JM29]

OK

So here is the summary of another (old) article, saying this has been observed and studied on the 4 ssp (now true species) of Triturus cristatus, and also on T. marmoratus. I haven't access to the full text.

Sincerely,

 

[JM29]

For a bit more details, see this other article.

Chromosome 1 heteromorphism is considered caracteristic of members of the cristatus-marmoratus complex (including carnifex, karelini, dobrogicus).

I think it's proven for these species.
Conversely, formerly other triturus (Ichtyosaura, Ommatotriton), Lissotriton) don't present this peculiarity.

Wether Calotriton is also heteromorphic is an open question (see Raffaelli, 2007).

Sincerely,

 

[uwe]

Hi JM,

thank you.

Uwe

 

[drew121]

I seem to find the first lot of eggs are no good , then later ones are fine . I wouldnt say as much as 50% are infertile though