Axolotl Facing Extinction

From the Discover News website

Beneath the tourist gondolas in the remains of a great Aztec lake lives a creature that resembles a monster -- and a Muppet -- with its slimy tail, plumage-like gills and mouth that curls into an odd smile. The axolotl, also known as the "water monster" and the "Mexican walking fish," was a key part of Aztec legend and diet. Against all odds, it survived until now amid Mexico City's urban sprawl in the polluted canals of Lake Xochimilco, now a Venice-style destination for revelers poled along by Mexican gondoliers, or trajineros, in brightly painted party boats.


But scientists are racing to save the foot-long salamander from extinction, a victim of the draining of its lake habitat and deteriorating water quality. In what may be the final blow, nonnative fish introduced into the canals are eating its lunch -- and its babies.


http://dsc.discovery.com/news/2008/11/03/water-monster-extinct.html

What can be done to prevent this happening?

They've been trying to prevent this for hundreds of years. People have been filling in, draining, and building on the lakes since the Aztecs. It's not like this is a new development.

It's always 'doomsday and brimstone' when it comes to the sensationalism media. Axolotls do NOT face extinction. They may become extinct in the wild, but so have many animals. Axolotls, however, have the distinct pleasure of making great pets. So there's no risk of them becoming extinct in the technical sense.

I would much prefer to see them focus their effort on critical habitat protection of Lake Chalco (the other lake it survives in), rather than restoration of already crappy habitat in the city. I suspect restoration is never going to come to fruition. The needs of the people living there are going to come before any critters. And if the people are just too poor to afford indoor plumbing and contained sewage systems, then there's really nothing they CAN do but continue to pour their sewage into the canals.

It's true that our pet and lab axolotls will never disappear, but wild A. mexicanum are genetically distinct from the domesticated version. It would be a shame if they became extinct in the wild because we would lose something unique. I agree that the problem isn't new, though.

slowfoot said:

It's true that our pet and lab axolotls will never disappear, but wild A. mexicanum are genetically distinct from the domesticated version.

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How so?

The genetics controlling paedomorphosis are very different at least - pretty much everything else hasn't been studied. Here are the papers addressing that:

Using lab strains: Voss, S.R. & H.B. Shaffer. 1997. Adaptive evolution via a major gene effect: Paedomorphosis in the Mexican axolotl. Proceedings of the National Academy of Sciences of the United States, 94(25): 14185-14189.

Later study using wild caught: Voss, S.R. & J.J. Smith. 2005. Evolution of salamander life cycles: A major-effect quantitative trait locus contributes to discrete and continuous variation for metamorphic timing. Genetics, 170(1): 275-281.

There's been really strong selection on the domesticated axolotl, plus outcrossing to tigers and inbreeding within lines. And I know it's just a silly personal observation, but they look different to me. This is the lab that I used to work in

Yeah, I recall that axolotls were crossed with tigers to get the leucistic trait into them.

hmmm....you worked with truly wild A. mexicanum? I've always thought those would be cool to see side by side the domestic animals.

They posted a video on national geographic on Nov. 3 on this subject.
The segment it called: "water monster" nearly extinct?


http://news.nationalgeographic.com/news/2008/11/081103-creature-video-ap.html

I am starting to see/hear a lot about axolotl around lately.

Not sure if it's been posted here before, but there's some more info on axolotl conservation projects here:
http://www.kent.ac.uk/anthropology/dice/research/azaxs/english/project/project.htm

Caleb, Thanks for the post. I checked out the website. There was a reference to hybridization between A. tigrinum and Axolotls being a concern. Does anyone know if their usage of tigrinum is equivalent to velasci?

There will always be plenty of axolotl in captivity, and axolotl as pets are becoming more and more common,

Have you read the rest of the topic?

The things in captivity are not the same as in the wild (and in my opinion should be given a different name as they are not true pure Axolotl). Furthermore that there are animals in captivity does not make the possible extinction of wild Axolotls less tragic

grunsven said:

Have you read the rest of the topic?

The things in captivity are not the same as in the wild (and in my opinion should be given a different name as they are not true pure Axolotl). Furthermore that there are animals in captivity does not make the possible extinction of wild Axolotls less tragic

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I agree. It is a bit like saying, "We don't ever have to worry about Gallus Gallus or Cyprinus auratus ever going extinct in the wild because there are so many chickens and Goldfish in captivity."

Perhaps the domestic stocks of Axolotls should be given a subspecific name like domestica or familiaris.

grunsven said:

The things in captivity are not the same as in the wild (and in my opinion should be given a different name as they are not true pure Axolotl).

Click to expand...

Tim S said:

I agree. It is a bit like saying, "We don't ever have to worry about Gallus Gallus or Cyprinus auratus ever going extinct in the wild because there are so many chickens and Goldfish in captivity."

Perhaps the domestic stocks of Axolotls should be given a subspecific name like domestica or familiaris.

Click to expand...

How are these not pure axolotls though?

From my understanding, and based on the article* I read (vide infra), many of the common strains present today are either:

- Descendents of the original Paris stock that was imported 1864, and were highly inbred, or;
- Descendants from a stock that was imported from Mexico.

* Malacinski, G.M. 1978, 'The mexican axolotl, Ambystoma mexicanum: Its biology and development genetics, and its autonomous cell-lethal genes', American Zoologist, vol. 18, no. 2, pp. 195-206

Jay.

They are axolotls, but have gone though years of genetic selection to live in laboratory or residential settings. The notion that wild and lab/home axolotls have notably different genetics is not farfetched. This can be seen in lab mice and rats compared to their wild counter parts and several other laboratory animals.

In the lab, Drosophila (Fruit flies) somewhere acquired a unique genetic transposable element (P element), which prevents them from mating with wild stocks. However, it has been extremely valuable for genetic research and these flies, which may have died if they had to reproduce in wild are have been indirectly selected for propagation in the lab.

In addition, the well-studied single-celled fungi, budding yeast in the wild has a genetic pathway that allows them to stick together, which is beneficial when growing on rotting fruit. However through unintentional laboratory selection for cells that do not aggregate, this genetic pathway was lost in lab strains.

Most definitely the use of axolotls in labs will alter them genetically from wild strains. Gone are the pressures of predation, finding a mate, finding food.... Enter pressures like non-seasonal reproduction, different color variations, regenerative capacities, cohabitation. Furthermore the fact that in order to isolate mutations and maintain genetic lines you have to do several rounds of inbreeding to isolate and purify the genes to define a "wild-type" or "mutant" makes it even more likely that selective pressures have occurred in the animal. So to the statement "How are these not pure axolotls?" The problem may be that they're too pure.

This is a major factor indeed, but there has also been crossbreeding between Tigers and Axolotls.

So captive Axolotls are inbred, (unintentionally) selected for life in captivity and have got Tiger genes. So they are definitly not the same as the wild animals.

There is an interesting article featuring A. mexicanum's habitat, past and present. It is the last article in an old issue of "The Axolotl Newsletter", Issue Number 26, Fall 1997. It can be read at: http://bigapple.uky.edu/~axolotl/pdf/26.pdf .

Considering the change in the habitat, can we even say that the Axolotls collected in 1863 even exists today. From what I have read elsewhere, it sounds like it shares it's shrinking habitat with the Mexican Tiger Salamander. Whatever physical barriers there may have been in the past for interbreeding of these two species may be gone.

True, the axolotl may be slightly different from the original wild species, but i hardly think they are different enough to say that they are not true axolotl. In addition you can never be sure where someones Axolotl hail from. I know a breeder in Mexico who caught a dozen in the late 80's from Mexico, and has been selling their offspring's babies ever since, so although it would absolutely be a tragedy if they went extinct in the wild, it would be technically be correct to say that the same species still exists in captivity, thanks to enthusiasts like us XD
-Danny

One thing the Axolotl has going for it is that it's bred at such a large scale in captivity. Same goes for alot of fish species like Neon Tetras and Celestial Pearl Danios which are virtually extinct in the wild but captive numbers far out do any populations that their wild habitats could ever sustain...

It's just too bad most other Salamanders don't get such exposure in captivity; which would definitely help garner public awareness. This whole banning species, leaving them to the perils they face in the wild would only insure extinction. If government organizations or zoos are conducting breeding programs it'd be nice to know, but salamanders aren't the "Poster" species such as Polar Bears, Harp Seal pups, or Pandas. It'd be nice if Salamanders at least got the same attention as frogs do. If Hobbyist are encouraged to keep and breed various salamander species now only would it create public attention and awareness, but this would insure that even if wild populations fail to survive these next few year; there will always be captive populations alive to ensure the species lives on.

Currently the thread of collecting salamanders is much higher that the advantage of a captive stock as ex situ conservation.
In my opinion ex situ conservation is very poor conservation at best.

all this talk just makes me sad:nono: