File 0006/2026 · Re: the defendant's record · Pages: 160 years
160 years in a tank (and a hamster)
Before asking an axolotl for papers, it's worth reading its record. The pet axolotl isn't a wild animal someone took out of a canal: it's the laboratory animal with the oldest self-sustaining colony in the world. Here's its case history.
Timeline
| Year | Event |
|---|---|
| 1863 | During the French intervention in Mexico, a military expedition catches axolotls in Xochimilco: 33 wild-type and one white male. |
| 1864 | They reach Paris alive and are split between the Jardin d'acclimatation and the Natural History Museum's Ménagerie. Zoologist Auguste Duméril gets six. |
| 1865 | They breed in captivity. Within a year Duméril's group has dozens of offspring, and some turn into land salamanders, scandalising the zoology of the day. Those experiments also produce the first reports of their ability to regenerate. |
| 1866–1868 | The first white axolotls appear in Paris, descendants of that male. From Paris, the colony spreads to labs across Europe. |
| 1957 | Rufus Humphrey's collection settles at Indiana University and becomes the reference centre for lab axolotls. |
| 1962 | Near Foot Lake in Willmar, Minnesota, an albino tiger salamander turns up. A year later it ends up with Humphrey. |
| 1963 | Embryos from the axolotl × tiger salamander cross die; Humphrey's team uses nuclear transfer and microsurgery to get embryos carrying the albino gene. That's how albinism entered the axolotl. |
| 1975 | CITES comes into force. The axolotl goes on Appendix II. |
| 2000 | Every axolotl in the reference colony now descends from the 1963 cross. |
| 2005 | The colony moves to the University of Kentucky: the Ambystoma Genetic Stock Center. |
| 2006 | The IUCN lists the wild axolotl as critically endangered. |
| 2017 | A genetic study estimates that lab axolotls carry about 6% tiger salamander DNA on average, and concludes they should be considered "a distinct, hybrid axolotl strain". |
Where the colours come from
- Leucistic (white or pink, dark eyes): a mutation in the edn3 gene. Every leucistic on Earth descends from a single white male caught in 1863. In 160 years, no other has entered the colony.
- Albino (white or golden, light eyes): a mutation in the tyrosinase gene that isn't axolotl. It came from the Minnesota tiger salamander in 1963. There is not, and never was, a wild albino axolotl.
- Melanoid, axanthic and the rest: other mutations kept and combined in captivity for generations.
In other words: a pet-shop albino axolotl is an animal whose colour was made in an Indiana lab with help from another species. To CITES, it's exactly the same as one taken from a canal in Xochimilco.
The Syrian hamster case
Now a story that sounds familiar. In 1930, zoologist Israel Aharoni digs up a burrow near Aleppo, Syria, and takes a female with her litter. Several die or escape; the survivors found a colony in Jerusalem. Virtually every lab and pet Syrian hamster in the world comes from there: genetic studies point to a single founding female.
In the wild, the Syrian hamster is doing badly: it lives in a small area of northern Syria and southern Turkey, is losing habitat to farming, and farmers fight it as a pest. The IUCN considers it threatened.
| Axolotl | Syrian hamster | |
|---|---|---|
| Captive founders | 34 animals, 1863 | One litter, 1930 |
| Years of continuous breeding | 160 | 95 |
| Wild status | Critically endangered, a single canal system | Threatened, a small area in Syria and Turkey |
| Captive colours | Leucistic, albino, golden, etc. | Cream, white, banded, long-haired, etc. |
| Animals in captivity | Hundreds of thousands, maybe millions | Millions |
| CITES listing | Appendix II | None |
| Papers to sell one abroad | Export permit, plus an import permit in the EU | The usual pet health papers |
Nobody thinks a hamster in a cage in Montevideo threatens a wild one in Aleppo. And they're right: the wild hamster's problem is in the fields of Syria, not in pet shops. Exactly the same holds for the axolotl. The only difference between the two is that one was put on a list in 1975 and the other wasn't.
Same origin, same history in captivity, same situation in the wild. One travels with its owner; the other, with a case file.
Entered into the record
Sources: Woodcock et al. (2017), "Identification of mutant genes and introgressed tiger salamander DNA in the laboratory axolotl", Scientific Reports 7:6; Reiß et al. (2015), "The history of the oldest self-sustaining laboratory animal: 150 years of axolotl research", J. Exp. Zool. B; "From Existential Knowledge to Experimental Practice: The Mexican Axolotl, the Paris Ménagerie…", Brepols; "Tale of Two Axolotls", BioScience 65(12); on the hamster: the history of Israel Aharoni and the IUCN assessment of Mesocricetus auratus; CITES Appendices.