Amphibians
Achoque
Ambystoma dumerilii · also called Lake Patzcuaro salamander, Patzcuaro salamander
An achoque is the axolotl’s less famous cousin: a large Mexican salamander that keeps its feathery gills and never leaves the water, living in a single shrinking highland lake. It is Critically Endangered, and one of its best hopes is a colony of them bred for over a century by an order of nuns who use the animal in a traditional cough syrup.
Overview
The achoque, Ambystoma dumerilii, is a mole salamander endemic to Lake Patzcuaro in the highlands of Michoacan, Mexico — nowhere else. Like the axolotl it is neotenic, keeping its larval gills, tail fin, and fully aquatic body into adulthood and breeding in that form. It is a suction-feeding predator of insect larvae, crustaceans, worms, and small fish, and at 25–35 cm it is bigger than a typical axolotl.
The nuns of Patzcuaro
The Dominican Sisters of the Monastery of Our Lady of Health have bred achoques for generations to make jarabe de achoque, a traditional cough and chest syrup. As the wild population crashed, their well-managed captive colony became one of the most important insurance populations for the species, now run with scientific support. There is no evidence the salamander extract treats coughs — the effect is from the honey and herbs — and the convent syrup now uses only captive-bred animals.
A failing lake
Lake Patzcuaro has lost water, silted up from deforested slopes, and been polluted by sewage and farm runoff, while introduced carp and tilapia eat achoque eggs and young. Survey catches have fallen from thousands to almost nothing over recent decades.
Status
Critically Endangered and still declining in the wild. The species survives mainly through assurance colonies at the convent, Mexican universities, and overseas zoos, alongside lake restoration and fish control. Trial reintroductions are under way.
Achoque: common questions
Is an achoque the same as an axolotl?
No, but they are close relatives with very similar biology. Both are Mexican mole salamanders in the genus Ambystoma, and both are neotenic, meaning they keep their larval gills and aquatic body and breed without transforming into a land animal. The axolotl, Ambystoma mexicanum, lives in the remnants of Lake Xochimilco near Mexico City. The achoque, Ambystoma dumerilii, lives only in Lake Patzcuaro, several hundred kilometres to the west, is generally larger, and has a broader head. Both are Critically Endangered in the wild while being kept in large numbers in captivity, the axolotl mainly as a pet and lab animal, the achoque mainly in conservation and traditional-medicine colonies.
Why do nuns keep achoques?
The Dominican Sisters at the convent in Patzcuaro have made a traditional achoque cough syrup for well over a century, using it to support the monastery, and over time they built up a captive breeding colony to supply it rather than taking animals from the lake. As the wild population collapsed, biologists recognised that the sisters had one of the largest and best-managed achoque colonies anywhere, and a partnership grew up in which scientists provide veterinary and genetic support and the convent maintains an insurance population and helps with research and reintroduction planning. It is an unusual case of a religious community becoming central to a species recovery effort.
Does the achoque syrup actually contain salamanders, and does it work?
Traditionally yes, the syrup was made by cooking down whole achoques with sugar, honey, and medicinal plants such as agave and quince, and it was taken for coughs, bronchitis, and other chest problems. Today many products sold as jarabe de achoque contain little or no salamander and rely on the herbal ingredients, partly for supply reasons and partly for conservation. There is no scientific evidence that salamander extract treats respiratory illness, and any soothing effect is most likely from the honey and herbs, which is true of many traditional cough syrups. The convent syrup is now made only from captive-bred animals.
Can the achoque be saved?
There is a serious effort, and the species is not without hope. Captive assurance colonies exist at the Patzcuaro convent, at Michoacan University, at Chester Zoo in England, and elsewhere, so the achoque is unlikely to go extinct outright in the near term. The harder problem is the lake. Recovery in the wild depends on reducing siltation by restoring the forested slopes of the catchment, cutting sewage and agricultural pollution, controlling the introduced carp and tilapia, and stabilising water levels, all of which require sustained work with the communities around Lake Patzcuaro. Trial reintroductions and habitat work are under way, but the wild population remains critically low.