Lake Pátzcuaro Salamander

AmphibianMexico

Dec 17

Ambystoma dumerilii

Lake Pátzcuaro

Surrounded by volcanic peaks in Mexico's western state of Michoacán, within a basin some 1,920 metres (6,300 ft) above sea level, lies Lake Pátzcuaro. Small towns encircle the lake's borders. These include several villages, such as Santa Fe de la Laguna, predominantly populated by the P’urhépecha — the indigenous people of the area. A handful of settlements float amidst the lake itself on islands like La Pacanda, today inhabited by only around 30 families, or the bustling island of Janitzio, which rises from the water like a domed turtle shell, its slopes covered with churches and monuments to the Catholic faith, leading to a mosaic-tiled statue at its pinnacle (of a priest who fought for Mexican independence). Along the shores are now-quaint towns with historic pasts; like Ihuatzio — its name meaning the "Land of Coyotes" in the Purépecha language — which was once the capital of the Purépecha kingdom until that title shifted to Tzintzuntzan ("Place of the Hummingbirds") on the northeastern shore of the lake, which was eventually conquered by the Spanish in the 1520s — and is now a town of some 15,000 people. The varied communities create a singular blending of cultures, combining the pre-Columbian traditions of the P’urhépecha, such as their 'new fire' celebration to welcome a new year, with devout Catholic traditions and extravagant Mexican festivals like the Day of the Dead (Día de los Muertos). All centred around, united by, Lake Pátzcuaro.

Stretching over some 130 km² (81 mi²), Pátzcuaro is the third largest lake in Mexico — and it's drying up. A combination of deforestation, droughts, and illegal water extraction have reduced the lake's volume by half since authorities began keeping track. Parts of the lake lie desiccated; desert landscapes of cracked soil. For the nearby settlements, the lake now provides less water and less food, and its drying will mean fewer tourists to support local economies. In large part, people are responsible for the lake's diminishing ¹ and If the lake continues to dry, it's the people who will suffer. But not just the people — it is the denizens of the lake itself who will suffer, have suffered, most of all.

The island of Janitzio in Lake Pátzcuaro.

Locals of the Lake

Lake Pátzcuaro is the sole home of a dopey-looking salamander, appropriately named the Lake Pátzcuaro salamander. Seen from head-on, its flat face bears a broad, goofy smile and an unfocused stare from little lidless eyes — a look of thoughtless serenity — framed by frilly gills which resemble sprouts of dark marine algae. Not that you'd see it in the wild. It dwells at the lake's bottom, "walking" atop silt and mud using thrusts from the little legs that protrude from its sides and swishes of its large, laterally flattened tail, adapted for a lifetime in the water.

Nowhere else will you find this amphibian in the wild — not in other parts of the country, nor in nearby streams and canals — it lives solely in Lake Pátzcuaro, and even then, only in part of it; an area covering less than 10 km² (3.8 mi²). That's the entire range of the species. Unsurprisingly then, its numbers aren't great, with estimates placing the wild population at under 100 individuals, and, equally unsurprisingly, the species is considered 'critically endangered' — one of the rarest amphibians in the world.

Conservation and Cough Syrup

Top to bottom; the Basílica de Nuestra Señora de la Salud next to the convent, nuns with a bottle of their cough syrup, rooms full of tanks of salamanders inside the convent.

The city of Pátzcuaro lies just south of the eponymous lake. Its streets, many paved in cobblestone, wind and weave upwards from the lake shore, lined with clay-walled houses painted red and white, with tiled roofs and balconies heaped with colour-filled flowerpots. Colonial-era mansions, museums, and palaces are grand monuments to history, while the vendors crowding the city's plaza, selling wooden figurines and woollen textiles, copper vases and sculpted candles, are the living city of today. It is here, in this city, that a Dominican convent of nuns, known as the Convent of Our Immaculate Lady of Health, has been raising salamanders for 150 years.

When the nuns began, their intentions were less than virtuous. The Lake Pátzcuaro salamanders, known as "achoques" to the locals, have been ingested for far longer than they've been protected. The P’urhépecha people have long worshipped this salamander as twin to the feathered serpent Quetzalcoatl — seemingly their version of the Aztec god Xolotl, typically associated with the axolotl. They practised their worship by making the salamanders into soup. A few nuns at the convent picked up on the idea more than a decade ago, but instead of making salamander soup, they cooked the salamanders into a syrup that they claimed could cure coughs, asthma, and anaemia. They sold the syrup, and it sold well — becoming the convent's main source of income, with a bottle worth 200 pesos (about $10) today.

Then the wild salamanders started to disappear. The waters of Lake Pátzcuaro began to fester with untreated sewage, invasive carp gobbled eggs and larvae, suffocating ectoparasites infested exposed gills, and fishermen killed salamanders in droves — 20 tonnes were fished annually In the 1980s — for soups or "medicines" or God knows what else.

Taking notice of the salamander's decline, and advised by a friar who also happened to be a trained biologist, the nuns felt compelled to save God's creation from extinction. Their cough syrup operation turned into a conservation mission. They ramped up their breeding efforts to create a sizable captive population — a population that has since overtaken the declining wild population threefold, with some 300 salamanders kept in two large rooms packed with aquariums. Three or four nuns live and work full-time at the breeding facility; feeding the salamanders earthworms, changing their water, taking their measurements, and pairing them up for breeding. The nuns now cooperate with experts at Michoacán University and the UK's Chester Zoo to optimally breed, raise, and study this fabled salamander species.

The convent's aquariums hold the largest population of these salamanders on the planet and, if they're not already, those two rooms will likely be the last bastion of the entire species. Extinction in the next 20 to 30 years is still a possibility. While some estimates place the wild population at 100 individuals, studies undertaken in 2000 and 2010 suggest that Lake Pátzcuaro might already be devoid of free-ranging salamanders. A failure in caretaking or breeding — the latter requiring careful management of the species’ remaining genetic diversity — at the convent could mean the end of the species. Thankfully, with the combination of devotion and expertise from this unlikely partnership of nuns and scientists, the species seems in good hands for now.

At the moment, reintroduction into the wild is a future prospect; the lake must first be cleaned of pollutants and invasive species, hunting must be regulated and those regulations enforced, and, of course, there still has to be a lake — the deforestation, illegal water extraction, and, on a larger scale, climate change, have to be curbed in order to restore or even maintain water levels. But when, or if, the day comes that Lake Pátzcuaro is livable once more, and the salamanders can return to their ancestral home, the population that rebuilds the species will hail from a complicated history of cough syrup and conservation, bred and raised under "God's roof", the fruit of unexpected alliances that spanned the globe.

Neoteny or "Adult Babies"

It might have come to your attention that the Lake Pátzcuaro salamander doesn't resemble most of the other 750 or so salamander species — not their adult forms, at least. It does, however, resemble a juvenile salamander. All juvenile salamanders look quite different from their adult forms thanks to undergoing a process of metamorphosis. Like frogs, salamanders hatch from their eggs — or in some cases, are born live from their mothers — as tadpole-like larvae; with no limbs, laterally flattened tails, and external gills. As a salamnder larva grows larger it begins to develop fore and hind limbs and eventually undergoes full metamorphosis, losing its external gills and taking on the full appearance of its adult form. The Lake Pátzcuaro salamander stops short of this last step. Upon reaching sexual maturity, some of its traits resemble that of an adult, such as its darker skin pigment and its set of internal lungs, while others, like its flattened swimming tail and frilly outer gills, are larval traits. It's stuck eternally in a kind of in-between state.

All of this may look and sound familiar and, indeed, the Lake Pátzcuaro salamander has a much more famous cousin that lives some 300 kilometres (~200 mi) to the east, in Mexico City; the axolotl. Both species display what's known as neoteny, i.e. becoming sexually mature while still retaining most of their larval traits. One benefit of this life-long child-like state is that they never lose their larval "superpower" of regeneration — damage to tissues is easily healed, entire limbs regrown, damage to the spine repaired, and even internal organs can be regenerated, from lungs to hearts to parts of the brain. The axolotl — a much-studied species that breeds well in captivity — can regrow its limbs and organs several times in a matter of weeks, each replacement a flawless copy. And on top of this, it's over 1,000 times more resistant to cancer than mammals.²

Peter Pan Salamanders

Despite the apparent benefits of neoteny, few salamander species remain "forever young".³ Many that do, however, happen to also live in Mexico, and much like the Lake Pátzcuaro salamander and axolotl, their entire wild populations are restricted to a single body of water.

Top to bottom; an Anderson's salamander (*Ambystoma andersoni*), a metamorphosed and neotenic Lake Lerma salamander (*Ambystoma lermaense*), and a metamorphosed and neotenic blunt-headed salamander (*Ambystoma amblycephalum*).

An hour's drive northwest of Lake Pátzcuaro, in the same state of Michoacán, lies Laguna de Zacapu (or Zacapu Lagoon). This small lake — with an area of less than 40 hectares (100 acres) and surrounded by the city of Zacapu — is the only place you'll find the critically endangered Anderson’s salamander in the wild. Like all neotenic salamanders, it has a swimming tail and external gills framing its wide, flat head.

Via the Angulo River, the Zacapu Lagoon connects to Mexico's second-longest river; the Lerma. Follow this river upstream and inland to the high-altitude city of Toluca — some 2,500 to 3,000 metres (8,200 to 9,840 ft) above sea level — and you'll reach the sole home of the Lake Lerma salamander. Unlike the previously mentioned salamanders, those of Lake Lerma do metamorphose — into terrestrial adult forms with functioning lungs and no external gills, that crawl into the surrounding grasslands — but only some do. The rest are neotic, never leaving the waters of their eponymous lake.

Travelling back towards Pátzcuaro, you'll come across the city of Morelia (the capital of the Michoacán state) and the blunt-headed salamander. It lives in fragmented pine forests around the city and breeds in stagnant and muddy waters, such as cattle ponds. Like those of Lake Lerma, some blunt-headed salamanders metamorphose and crawl onto land, while others don't and remain in the water — although it's hard to see the appeal of living one's whole life in a cattle pond. Unsurprisingly, this species is also considered 'critically endangered'.

A metamorphosed (top) and neotenic (bottom) western tiger salamander (*Ambystoma mavortium*).

Some salamanders only exhibit neotony in the most extreme of circumstances. A case in point is the tiger salamander — a species that ranges throughout much of North America. In 1993, a herpetologist shone his light into an abandoned reservoir in Wisconsin, illuminating the squirming forms in the dark, polluted waters. These turned out to be a population of tiger salamanders dwelling in the long-forgotten pools. Adults of this species are terrestrial, only returning to water to lay their eggs, but this odd community was living fully aquatically. And these were adult salamanders, sexually mature, but with the paler skin of larvae, flat swimming-tails, and external gills. These salamanders, hatched in the dark and wet world of a reservoir from which they couldn't escape, adapted to survive by foregoing full metamorphosis and remaining in their more aquatic larval states — they became neotenic. However, the discovery of this neotenic population is an exception to the general metamorphic rule, in that, under normal circumstances, most tiger salamanders do undergo full metamorphosis.

So far, all of the neotenic salamanders we've met have been close cousins — all in the genus Ambystoma, a group of around 33 species known as mole salamanders. But a few other salamander groups likewise refuse to grow up. The genus Necturus is one such group. Comprised of 8 species, these salamanders are adorably known as waterdogs or mudpuppies. They're distinguished by their elongated bodies — the common mudpuppy measuring up to 33 cm (13) long — with a long span between their stubby front and hind limbs (like a dachshund) and a very laterally compressed tail. All waterdogs and mudpuppies are fully aquatic — typically residing in cold and clear bodies of water throughout the eastern U.S. and Canada — and neotenic — with the characteristic flat-headed larval look and bushy external gills.

Then there are the sirens. Not to be confused with the singing and sailor-luring creatures of Greek myth, the real-life sirens are 7 species of amphibians belonging to the family Sirenidae.⁴ The sirens are very eel-like; so much so that they're often mistaken for the elongate fishes (and are sometimes known as "mud-eels” or “ditch-eels”, as they're often found in shallow waters and spend the day hidden under vegetation or mud). Sirens only have a single set of limbs right behind their heads, while the rest of their slimy, serpentine bodies extend far behind them — to a maximum length of nearly a metre (3 ft), in the case of the greater siren. They look like very stretched-out versions of the other neotenic salamanders, and while they also have external gills, their gills aren’t very efficient and sirens have to surface occasionally to gulp air into their lungs.

For our final, and probably strangest, Peter Pan salamander we have to cross the pond to Europe — more specifically, to the Adriatic coast (from northeastern Italy down to Montenegro). This is a coastline of grey-white limestone crags and cliffs, sculpted and perforated by flowing waters that, over vast spans of time, created sprawling subterranean systems of caves and tunnels. In these dark and dank underworlds, lives the olm. Its cylindrical, skinny body, with two pairs of tiny limbs protruding from either end, slithers through deep underground lakes and streams some 300 metres (985 ft) below the surface. No sun touches its skin, so it is pale; a pigmentless white or pink. And without light, it has no use for eyes, so its face — flanked by a pair of pink gills — is a featureless snout with nothing but a mouth. A mouth that eats anything it can engulf, from insect larvae to tiny fish, found in the blind darkness by smell, taste, hearing, and electroreception. But food doesn't often venture down into these waters — the olm is Europe's only cave-dwelling vertebrate, after all — so it has learned to fast; able to go without a bite of food for up to 10 years. A long time, yes, but perhaps not too long for a creature that can live for up to a century.

A common mudpuppy (*Necturus maculosus*).

A reticulated siren (*Siren reticulata*).

From the unparalleled regenerative abilities of the axolotl, to the variable neoteny of the Lake Lerma salamander, and the great lifespan of the cave-dwelling olm — these salamanders are some of the oddest animals on the planet, like creatures from fantasy and legend made real. And our relationships with them, our histories and mythologies, are complicated and rich. The axolotl was once an Aztec god of fire and lightning that escaped his impending sacrifice by becoming a salamander. Today, his descendants are kept as pets — bred to look white or black or a mottled mosaic — and researched in labs the world over, by scientists seeking a “fountain of youth”. In Europe, the first witnesses to the olm described the pale, blind creature as a “young dragon” and its discovery partly heralded the birth of biospeleology; the exploration of caves in search of their strange creatures. While the tale of the Lake Pátzcuaro salamander and the convent of cough-syrup-making nuns is among the strangest conservation stories ever told

¹ Most obviously, there is the direct and illegal draining of the lake's water — not insignificant amounts, with the committee responsible for preventing such draining estimating that they stopped the theft of “600,000 litres of water per day”. Deforestation in the surrounding areas disrupts the local water cycle, meaning less rain, and with fewer trees less water is stored, while fewer roots to bind the soil means more erosion, runoff, and an increased risk of floods when rain does fall. As for an increase in droughts, the link between anthropogenic climate change and an increase in prolonged and extreme weather conditions — droughts in some areas, floods in others — is pretty well proven at this point.

An axolotl (*Ambystoma mexicanum*) in a lab.

² By nature of the species’ water-dwelling habits, wild populations of axolotls are difficult to tally, but like their cousins from the west, axolotls are now restricted to one lake; Lake Xochimilco in southern Mexico City. Hopeful estimates place the wild population at 1,000 adults — lower predictions are a depressing 50. In contrast, there are now likely more than one million axolotls being bred and kept in captivity, either for research or as pets.

Unsurprisingly, this extraordinary species — a mixture of Peter Pan and Wolverine — has been extensively studied by scientists trying to unlock its biological secrets and apply them to human medicine. The Lake Pátzcuaro salamander has had no such popularity in labs around the world (for good or ill), but presumably, it shares most of the same "superpowers" of the axolotl. Current captive breeding efforts are rightly focused on saving the species, and, in the case of the nuns, making a buck on the side from their cough medicine — investigating the possibility of eternal youth may go against God's decree.

³ In the case of the axolotl, eternal youth extends some 15 years in captivity — not a short life for an animal of its size, but hardly forever. For comparison, a metamorphosed tiger salamander can likewise live for up to 15 years or more, while some more distantly related species like the fire salamander of Europe, can live for nearly 25 years in captivity.

⁴ In turn, the salamander sirens in the family Sirenidae are not to be confused with the mammalian sirenians in the order Sirenia — also known as the sea cows, they consist of three manatee species and the dugong.

**Where Does It Live?**

⛰️ Among the muddy lake bed.
📍 Endemic to lake Lake Pátzcuaro in Michoacán, Mexico. ¹

‘Critically Endangered’ as of 21 August, 2015.

IUCN

Size // Small
Length // Up to 35 cm (13.8 in)
Weight // N/A
Activity: Mostly Nocturnal 🌙
Lifestyle: Solitary 👤
Lifespan: N/A
Diet: Carnivore
Favorite Food: Aquatic invertebrates and small fish 🐟
Class: Amphibia
Order: Urodela
Family: Ambystomatidae
Genus: Ambystoma
Species: A. dumerilii

This rare salamander is endemic to a single lake (Lake Pátzcuaro), in the western Mexican state of Michoacán. While the lake is the third largest in Mexico — some 130 km² (81 mi²) — the entire range of the species is thought to fall within an area of just 10 km² (3.8 mi²).

The Lake Pátzcuaro salamander is a relative of the more famous axolotl (both are in the genus Ambystoma), and like the axolotl, it also exhibits neoteny — it becomes sexually mature while still retaining most of their larval traits, such as a flattened tail and external, frilly gills. The Lake Pátzcuaro salamander also retains its superpower-like regenerative abilities, easily able to heal tissues and regrow entire limbs.

Unfortunately, this salamander's regenerative abilities have also made it attractive to humans hoping to share in its "eternal youth" — mostly via consumption. Such as the local P’urhépecha people, who have traditionally made the salamander into a soup.

At the same time, the P’urhépecha have long worshipped this salamander as a twin to the feathered serpent Quetzalcoatl — seemingly their version of the Aztec god Xolotl, typically associated with the axolotl.

In the nearby city of Pátzcuaro, a convent of Dominican nuns heard about the salamander's (dubious) "medicinal properties", and saw an opportunity for a business venture. They cooked the salamanders down into a syrup that they claimed could cure coughs, asthma, and anaemia. It sold so well that it became the convent's main source of income and, more than a hundred years later, they still sell this (very questionable) cough syrup — a bottle costs 200 pesos (about $10) today.

Meanwhile, the population of wild salamanders began to plummet. Untreated sewage oozed into the lake, and invasive carp ate salamander tadpoles and eggs while proliferating ectoparasites infested their gills. Fishermen killed salamanders in droves — 20 tonnes were fished annually In the 1980s. And the lake itself is now disappearing through a combination of deforestation, drought, and illegal water extraction (which have reduced the lake's volume by half since authorities began keeping track).

Fortunately, the salamander-syrup-making nuns noticed the decline in wild salamanders. Instead of raising salamanders solely for cough syrup, they began to breed and raise a captive population for the purposes of conservation. Today they work with experts at Michoacán University and the UK's Chester Zoo to maintain the world's largest population of these salamanders inside their convent, where two large rooms are packed with aquariums which hold around 300 salamanders.

The wild population, however, hasn't fared well. While some estimates place the population at 100 individuals, a few studies suggest that Lake Pátzcuaro might already be devoid of its salamanders. The species is considered 'critically endangered' — one of the rarest amphibians in the world.

With both devotion and expertise, the unconventional partnership between faith and science can hopefully keep the species alive until re-establishment into the wild is possible.