There's a fairly big difference between "destroy them all!" and "don't spread them around!"
Chances are the offspring are infertile but even if not I doubt they pose a threat to the domestic paramesotriton population (or wild for that matter), especially if the sellers are honest about their origin. They still make nice pets. When did you ever see a cb paramesotriton in a pet shop? Never I bet. Wouldn't it be better to buy a cb F1 hybrid over a wild collected animal suffering in a pet shop?
Mark, the key word is "honest", there. As long as everybody knows that those are hybrids and treats them accordingly, they are absolutely not a problem, i fully agree. The trouble comes when somebody is dishonest about it or simply ignores the fact that they are hybrids, that´s when those animal could potentially be problematic. And it´s a situation that most of us would really like to prevent.
Personally i wouldn´t like to see CB hybrids offered through pet-shops for the reason above.
I know you are sick and tired of all this, Erfus, i do xD I hope you understand, though, why it is an issue for so many of us.
They are lovely little things and a credit to your hability as a breeder, as this genus is not the easiest to breed or raise. We just hope they are never given the chance to perpetuate the genetic introgression into other bloodlines (provided that it´s even possible).
Hmm yes conserve the bloodlines,,, Its not like we have already messed them up by not applying natural selection via predation, starvation, weather etc, thus letting weak animals live and breed themselves. We also tend to breed closely related animals, thus increasing likelihood of expression and amplification of recessive traits including genetic diseases in the bloodlines.
To me it would seem that having an animal fit to survive is better than a pure bloodline, it is rarely the same thing.
Hi, thanks for commenting on the different views.I agree to keep the bloodlines pure, This hybridization was not searched but I have to admit that I have really wanted to see the development of these offspring because they are two very different species morphologically and view them in adult size seems very interesting.
No way I'll sacrifice the animals!, I have the opportunity to enjoy a group paramesotritones cb.
Regarding breeding, the metamorphic need to be removed rapidly from a land area aquaterrariums because they are very likely to drown when they complete metamorphosis.
Movements are shy and slow compared with other youth from different species but with growth, this behavior is changing.
I know you are sick and tired of all this, Erfus, i do xD I hope you understand, though, why it is an issue for so many of us.
But Jesper, i´m very concerned about all those other factors too. What i´m saying here (because it´s what´s on topic) is that hybridisation is ONE of the things that don´t contribute at all to the future of caudate species in captivity. I don´t necessarily think it´s the most important factor, but it´s certainly one of the big concerns.
Just because people don´t apply any possitive selection, or abuse inbreeding, it doesn´t mean that going around hybridating species is acceptable or good. We should be taking into account all those factors to the best of our possibilities, not just continue to ignore them as if such things don´t matter.
"To me it would seem that having an animal fit to survive is better than a pure bloodline, it is rarely the same thing. " Well, certainly if you are thinking of bloodlines as in breeds xD Those are no good....I would prefer to see fit animals that are coherent with wild populations, though, that would be my ideal. I´m greedy
I believe that the conservation of the pure lineage they should do them herpeteologos qualified and being employed with wild animals at semifreedom (servants in his own habitat and doing natural selection). We can collaborate doing donations and helping to the qualified Personnel.In this hobby we have animals fed on a diet very different to the diet of the wild populations, though the urodelos are of the same species, different populations are mixing, we can try to recreate to the maximum his original habitats but it is a task impossible to recreate his authentic habitat. the problem might be that the environmental administrations do not give sufficiently subsidies to repopulate amphibians,
The animals in our care are dead to the species. Any ex-situ conservation efforts will be conducted by organisations that have the facilities and funds to assess genetic heritage and health of the animals before breeding efforts even commence, especially when visually similar species exist. There is no sure fire way for a hobbyist to replicate the natural selection pressures that a species has evolved to cope with, unless the species is native and kept in-situ. Even outdoor ex-situ efforts may be exposing animals to diseases and environmental conditions unfamiliar to them. The offspring we raise in captivity do not represent the genetic variation of their wild counterparts and therefore are genetically weak, irrelevant of bloodlines.
I suppose the question for me is why should we care about the survival of a species in captivity? What good does being in captivity do the species? The average dog or cat owner takes no interest in the survival of the breed, they just want companionship of a pet. Does a newt owner have a pet newt or is there more to it? I think people like the idea of there being more to it because it justifies keeping some newts in a glass tank and makes them feel like they are contributing in some way. This could be viewed as hypocritical considering all captive caudates originated from wild collections which did nothing but reduce the gene pool for a population.
Most of the food on our plates, be it animal or plant, is the result of hybridisation. The world didn’t stop turning. Humans are a product of the life that has developed on this planet so however much we screw up it up it’s all perfectly natural. And if you disagree with that theory just think forward 55 million years when the sun runs out of hydrogen and goes super nova on us. No amount of genetic integrity will save them from that.
Just want to make some corrections. Its 5 billion years Mark. Not 55million. Its even more than the actual age of earth, 4,6 Billions (460million years) A star with mass and size of our sun can only live for approx 10billion years till it runs out of fuel.
It's not always true that 'professional' amphibian ex-situ efforts assess the genetic heritage of animals used in projects. The vast majority use animals taken from rapidly disappearing populations, so although they are all from the same population, all animals are rarely genotyped etc. For most projects, the effective population size is absolutely tiny, too, with very few founder animals and many closely related offspring. These projects rarely if ever subject animals to natural selection, other than culling excess or obviously ill animals, often because zoos are uncomfortable doing this and/or do not have the licenses to subject animals to predation etc, or because so few offspring are generated they can't afford to lose any. Despite all this, reintroduction projects have been successful or semi-successful in the past, and look at the number of naturalised populations of alien species that started from small populations of dumped pets, often CB (e.g. banded newts in Spain, alpine newts in the UK etc).
Despite this, I do agree with Mark that any pet animals are no longer part of wild populations and that it is not ethical to attempt reintroductions in one's back garden, for both ecological/genetic reasons (disease, non-native genes, altering fitness of surviving wild populations by introduction of new genes etc) and welfare (many animals will die, particularly as there is a good reason why native populations have disappeared). Exceptions may exist where extremely rare species only exist in captive populations (imagine if the golden toad was being bred by a hobbyist).
I think that most CB hobbyist populations, particularly when large numbers of animals are reared in relatively natural tanks and where juveniles are allowed to 'get on with it', rather than being hand-fed, populations can remain relatively fit. This is not to say that they are entirely the same as wild animals, but they are perfectly viable. As long as populations are managed to an extent (stud-books, keeping track of which animals are related to which and how, avoidance of line-breeding), they can remain relatively similar to wild animals. In fact, the altered selection pressures in captivity are likely to produce animals that are much better at coping in aquaria etc and make healthier, happier pets.
Many of the differences we see between wild and CB animals are highly unlikely to be genetic (there haven't been enough generations to see these effects), and are much more likely to be due to plasticity in the salamanders in response to different environmental conditions. Most species develop and grow much faster in captivity due to more plentiful food and more clement conditions, and are fed diets that are vastly less varied than wild animals receive. The lack of winter-summer cycling has important effects on morphology and fecundity, too. The list goes on.
Therefore, I think the main reasons to keep genetically healthy populations are aesthetic (if we like the look of the them as wild-type) and sustainability-related (ideally, we want to be independent of new imports in case they stop and so we are not responsible for declines and extinctions), but providing appropriate conditions long-term will have an effect on the viability of captive animals long before responses to selection kick in. Mallorcan midwife toads (Alytes muletensis) have been shown to lose anti-predator behaviour after around 8 generations, but few captive salamander populations are past F1 or F2 and even longer would be needed to start seeing more obvious genetic problems that could threaten viability.
This brings us back to hybridisation. Reasons to avoid this are either aesthetic (we prefer the idea/look of having wild-type animals, rather than hodge-podges) or sustainability-related (hybrids are often less fertile, massively more fertile, sterile or generate sterile F2s), all of which could seriously damage the long-term viability of captive populations, particularly as most species are capable of living a LONG time and of generating MANY offspring. If people want to generate hybrids on a large scale, I won't be buying them, but as long as they are advertised honestly and don't get interbred with pure species newts (unlikely, in reality) I don't think it is particularly damaging.
PS, the pictured animals look very healthy. Out of interest, were they easier to rear than non-hybrids?
Hybridisation or any other of the factors in captive breeding, doesn´t worry me because of conservation issues or the populations in the wild (although in my ideal universe that would be part of the concerns). It worries me because i like all caudate species just as they are There´s more to it, though, and it has all to do with your question "why should we care about the survival of a species in captivity". I think we really should care. We should, because their future really does depend on us caring since we are in charge of that future. I worry because i don´t want caudates to go the same way as any other domestic species has. Their quality of life depends entirely on us and there´s more to it than decent housing and food.
I´m fully aware that it is imposible for a hobbyist to replicate natural selective processes or guarantee a large genetic variation in captive populations but the problem i have with this is the assumption that because we can´t do it properly then anything goes...I don´t see it as both extremes being the only options. I think some degree of effort on our parts can ensure that future captive populations will be healthy in the future. When i say i´d like captive populations to be coherent with wild populations i mean that i want them to be healthy, viable and diverse. I think trying to use nature´s standards for what works is a wise thing to do, even if we can´t get it entirely right, it will always be better than no effort at all.
If something works perfectly fine just as it is...why change it? And why allow it to change dramatically and uncontrollably, knowing that it will only impoverish their future?
On the subject of wether there is more to it than just having a pet, i have to say that for me there is, but it´s not a delussion of "working with the species" as we have discussed in the past, but purely a matter of aesthetic delight. I keep newts because just looking at them makes me happy, and what makes me happy is the thought of the beautiful naturally ocurring species in all its splendor. I really do like them just the way they are. There is a very real aesthetic pleassure in just observing these creatures.
I´ve used the words genetic integrity before, but i realize that it gives the wrong impression (after all in the wild genetic introgression of some form or another is quite common). I don´t use it solely in reference to unhybridized animals (which i don´t think wild hybridisation events can really be compared to a captive one), but also to their health and fitness, genetic and fenotipic.
The world certainly doesn´t stop turning, but it does become an impoverished version. One of the benefits of avoiding all the things that have been commented, hybridisation, lack of selective pressures, etc, is that you retain diversity and general fitness, if not forever (fat chance), at least for longer than otherwise. I´d personally like future generations to enjoy a planet that doesn´t suck...mind you, my hopes dwindle inexorably..
Edit: Chris put it a thousand times better than i did xD