Inbreeding newts?

Hey,as I said in a previous post I'am getting Kaiseri newts soon(just need to setup the tank first)And I'am also planning on breeding them and I'am going to get a male and female(brother and sister) and I was wondering if inbreeding them will make the babies come out deformed and have genetic defects?So is it okay to breed brothers and sisters or no?

That sounds like a bad idea. Do that with a common species at the very most...

Weakens captive stock.

Inbreeding is a one of the great tabboos, so don't expect to get any great reviews. Personally I would stay away from inbreeding, If you were trying to establish a new strain of newt (like many breeders establish new strains of guppy), then by all means go for it, but like posted above if you wanted to experiment with genes and inbreeding use a more common amphib. and be willing to cull the offspring. I'll give you a little info about inbreeding and you can decide, but I would stay away from it. I'm assuming your offspring will be sold/given away as pets and if these offspring are used to breed then you'll be providing a genetically weakened newt into the gene pool. Which will not only hurt your offsprings offspring, but could eventually lead to a weakening of said gene pool (I know I'm being a little dramatic, but hypothetically it could happen). I know that interbreeding can also cement genes, giving the offspring Homozygous (dominant genes), but the offspring can also acquire unwanted Heterozygous (recessive) genes. These unwanted recessive genes are known as "bad genes" and can be the source of many unwanted traits, such as suppressed immune systems. Inbreeding is mainly used to try and "set" a trait. This is seen very often in cats and dogs when an individual is trying to establish a new breed. breeding two individuals (say sister and brother) which share the same traits will give the offspring they produce dominant genes to those traits, meaning that those offspring being bred will carry the "good traits" as dominant genes. But the tricky thing is that most of the unwanted traits are unseen to the naked eye. This is why some breeds of dogs often have issues with hip displasia and some cats have issues with their eyes and ears.

To produce cats which closely meet the breed standard, breeders commonly mate together animals which are related and which share desirable characteristics. Over time, sometimes only one or two generations, those characteristics will become homozygous (genetically uniform) and all offspring of the inbred animal will inherit the genes for those characteristics (breed true). Breeders can predict how the offspring will look. "Line-breeding" is not a term used by geneticists, but comes from livestock husbandry. It indicates milder forms of inbreeding. Line-breeding is still a form of inbreeding i.e. breeding within a family line and includes cousin/cousin, aunt/nephew, niece/uncle and grandparent/grandchild. The difference between line-breeding and inbreeding may be defined differently for different species of animals and even for different breeds within the same species. It is complicated by the fact that a cat's half-brother might also be her father!



"However, inbreeding holds potential problems. The limited gene-pool caused by continued inbreeding means that deleterious genes become widespread and the breed loses vigour. Laboratory animal suppliers depend on this to create uniform strains of animal which are immuno-depressed or breed true for a particular disorder e.g. epilepsy. Such animals are so inbred as to be genetically identical (clones!), a situation normally only seen in identical twins. Similarly, a controlled amount of inbreeding can be used to fix desirable traits in farm livestock e.g. milk yield, lean/fat ratios, rate of growth etc. In human terms, inbreeding is considered incest; cats do not have incest taboos.

INBREEDING
(Mating of closely related individuals)

PROS
Produces uniform or predictable offspring.
Hidden (recessive) genes show up and can be eliminated.
Individuals will "breed true" and are "pure."
Doubles up good genes.
Eliminates unwanted traits.

CONS
Doubles up on faults and weaknesses.
Progressive loss of vigor and immune response.
Increased reproductive failures, fewer offspring.
Emphasis on appearance means accidental loss of "good" genes for other attributes.
Genetically impoverished individuals."

excerpt from "PROS AND CONS OF INBREEDING" by Sarah Hartwell


Hope this helps a little.

I think you ask an excellent question, eft!

Ideally, we should choose unrelated animals to breed with each other.
However, in reality many captive bred caudates go back to just a few lines and are so closely related that it may simply not matter much if two parents are siblings, cousins, second cousins or whatever.

Even in the wild, many populations may be very inbred. This may be especially true of Neurergus, which live in isolated remnant populations that probably have little or no genetic exchange with one another. If any such population gets decimated to a few animals during a bad year, and then increases in number again, all the subsequent offspring will be more or less siblings and cousins and will share very small genetic variability.

The bottomline is, it may not matter all that much. As far as I know, no one has documented any clear inbreeding effects among captive caudates. Ultimately, the only way to get "fresh" genetic material into some captive lines may be more wild-caught imports, which is something few people would want to happen.

Also, inbreeding does not "cause" defective genes - what it does is make it more likely that two individuals with a recessive gene produce offspring homozygous for that gene. In other words, inbreeding can increase the frequency of a "bad" gene that is already in the population.

Okay,thanks.Just wanted to hear it from the experts that its safe.And yes I'am aware of the small population problem in Iran with the Kaiseri so getting a wild Kaiseri won't be good for the species.It's illegal to get wild exports for what I know.And that's what got me interisted to breed them.lol never too young to start careing about animals

As Molch says, there's no evidence of inbreeding depression in amphibians.

Use of the forum search function will provide a wealth of data on this commonly asked question.

There are some indications of inbreeding issues in axolotls.

In the case of N.kaiseri i´d say it is particularly important to avoid inbreeding when possible for one very good reason, there will be no introduction of new blood from wild populations. If we don´t take care of the captive populations, once they are empoverished, there´s no going back, which is the same situation as with axolotls, currently.
One huge difference with wild populations is that even if a particular population is highly inbred, it´s subject to selective pressures that will eliminate the worst effects or unsuitable individuals. In captivity that simply does not happen which makes it substantially worse because there´s no refinement of the populations, no possitive selection.

As johnny says, there´s has been quite a bit of debate about this issues in the past, make a search.

One little thing...JacksonR, if you realise that there can be serious negative effects in the long run, why is wrong to inbreed N.kaiseri, but is ok to do so with a common species? I find it equally objectionable irrespective of the species.


Also, fire_newt while your post will be very informative for many people you made a couple of mistakes there. Homozygous has nothing to do with dominant, and heterozygous is not the same as recessive, those are different things. "Bad genes" can be either dominant or recessive (or otherwise) they are not necessarily recessive. There was quite a bit of confusion with those terms in the post and i thought i´d clarify.

Azhael said:

One huge difference with wild populations is that even if a particular population is highly inbred, it´s subject to selective pressures that will eliminate the worst effects or unsuitable individuals. In captivity that simply does not happen which makes it substantially worse because there´s no refinement of the populations, no possitive selection.

Click to expand...

I'm not so sure about this one, though. Life in captivity likely exerts its very own selective pressures. It's possible that we're slowly breeding a population that is particularly well adapted to, well, captivity

The question still remains, though: how can you know that two random kaiseri are not closely related? Doesn't just about everyone get their newts from one or two lines anyways?

Ah, Molch, but that´s exactly what i have a problem with. I have no interest in domesticated caudates, i like them wild and fierce xD
I think it´s a bit tragic that everytime a species becomes stablished in the hobby it inevitably follows a path of domestication that separates it further and further from the original.

As for knowing wether they are related or not, it may be difficult, but generally if you manage to get information from the breeders you may be able to stablish that their bloodlines come from separate imports or individuals and thus are at least unlikely to be related.
The problem you mention about only one or two bloodlines existing does happen, L.laoensis being an excellent example currently, but in the case of N.kaiseri i think that´s not the case at all. As far as i can tell there have been independent breedings from several imported groups in the past, plus there are still many WC individuals in the hobby that can produce new bloodlines.
I´d like to make it clear that i´m not saying that no inbreeding shall be tolerated *insert image of a shacking fist*, i´m merely saying that it´s a good thing to avoid inbreeding whenever possible, it is all benefits even if it requires a bit of an extra effort. The road of not paying the slightest mind to these issues ends badly...
Caudates are tolerant of endogamy, but everything has its limits. Fish are too, and yet if you ask a guppy enthusiast they´ll tell you that captive bloodlines have literally decayed to ashes.

Azhael said:

Ah, Molch, but that´s exactly what i have a problem with. I have no interest in domesticated caudates, i like them wild and fierce xD
I think it´s a bit tragic that everytime a species becomes stablished in the hobby it inevitably follows a path of domestication that separates it further and further from the original.

Click to expand...

:happy: yeh, I agree, but what to do? We can't replicate wild conditions in captivity, so inevitably our captive newts are subject to different selection pressures. The only way to keep them close to Mama Nature's Original is to keep infusing wild-caught bloodlines, and I'm not sure I would want that to happen, at least not in the case of highly endangered species....

I see two ways of maintaining a decent level of genetic variability and coherence with wild populations and regular introduction of wild blood is obviously one of them. However there´s a huge difference between a careful, properly done, monitored, legal importation and your average import which is as ecologically responsible as watering gardens with batery acid.
I think it can be done in a responsible way, even with endangered species. The key is in a proper understanding of a population´s situation and a proper conduction of the import. You don´t need large numbers, you just need a very reduced number of individuals (or better yet, some eggs) and a responsible use of them. This of course is complicated, but who said it had to be easy?
The other way i see to prevent the worst of domestication and genetic divergence is to apply some degree of healthy selection. As you say, captivity implies a completely different set of selective pressures, and you can´t scape from that. But what you can do is minimize this by eliminating aberrants (which is the opposite of the current trend...sadly), applying some degree of competition between larvae and juveniles instead of raising as many as possible regardless of their fitness, etc. This last point i think is particularly noxious. Out of up to 300 hundred eggs that a single female may produce a year in the wild, only 1-2 may survive to adulthood, while in captivity, under the right conditions you can raise 90% of those. That to me is clearly a bad idea. I understand that massive production is desirable for commercial purposes but it´s SO against the intended process. They have large clutches because the vast majority of the offspring are supossed to die! Now, i´m not saying, cull all of them but two, i´m saying, let them compete, let the fittest prevail. It may sound awful to some people, but it´s natural and it´s very benefitial.

yes, I like the idea of large, pond-like tanks in which larvae grow up naturally and compete. My alpine newt larva Hannibal grew up that way (he's morphing now), and he's one big aggressive honking specimen Next year, I will let them breed all au naturel in their 40 ga tank, and I'll see how many morphs I'll end up with...

On the other hand, if captive breeders want to produce enough newts to replace wild mass imports, they will have to produce certain numbers. Also, many larvae in the wild probably don't die because they are genetically inferior, but just because they ran out of luck, e.g., big newt came and ate them, pond dried out, whatever.

Of course there is an element of chance, but largely, the fittest to whatever pressures may be present are the ones more likely to survive. In the particular case that you pressent where big newt eats small newt, it´s not just chance, the hability of big newt to catch small newt and small newt´s habilities to scape also matter a great deal.
Anyway, i´m not proposing that we can emulate nature, not by any means, but i do think certain actions help minimize the impact of domestication even if they don´t completely eliminate it and as such are better than nothing.
About the need to produce large quantities of CB caudates to supply the market, i don´t know, demand is not that high anyway, broadly speaking, and if that demand can be satisfied by several breeders offering smaller individual quantities of quality specimens rather than by one single breeder offering mass reared animals, i think the former is better.
It´s a complicated issue that has no easy solution, but i think it´s brilliant that we are at least discussing it again even if it serves just to raise people´s consciousness about it.

We don't need color morphs of an endangered species!! I agree with flying spagetti monster guy.

Some inbreeding will happen but don't intentionally breed a brother and a sister. If that's what you want to do, DO NOT GET KAISERI.

I simply said do it with a common species *at the most.* I'm not promoting it, but at least do not to an endangered animal.

Azhael said:

There are some indications of serious inbreeding issues in axolotls.

In the case of N.kaiseri i´d say it is particularly important to avoid inbreeding when possible for one very good reason, there will be no introduction of new blood from wild populations. If we don´t take care of the captive populations, once they are empoverished, there´s no going back, which is the same situation as with axolotls, currently.
One huge difference with wild populations is that even if a particular population is highly inbred, it´s subject to selective pressures that will eliminate the worst effects or unsuitable individuals. In captivity that simply does not happen which makes it substantially worse because there´s no refinement of the populations, no possitive selection.

As johnny says, there´s has been quite a bit of debate about this issues in the past, make a search.

One little thing...JacksonR, if you realise that there can be serious negative effects in the long run, why is wrong to inbreed N.kaiseri, but is ok to do so with a common species? I find it equally objectionable irrespective of the species.

Click to expand...

Alright,so I guess I'll get a male or female and then a male or female from another breeder just to stay on the safe side.

JacksonR said:

I agree with flying spagetti monster guy.

Click to expand...

Az, dude, friend, I think he means you :frog:

Newts ain't cats or dogs. Their is little depression or mutation shown in amphibians due to limited gene pools. Some if the mutations that show up are not accidental and have been selected for on purpose. Their is nothing wrong with breeding sibling amphibians in general.

Probably better to be on the safe side and breed *somewhat* unrelated animals! Brother and sister, I wouldn't.

Try to preserve a gene pool. Frankly, that would be an unforgivable nature sin. lol