The only known natural habitat of the salamander-like reptile are Mexico City’s Xochimilo network of lakes.
But recent attempts by biologists to net the creatures in the lakes resulted in none being found.
The disturbing news could mean the species of Mexican walking fish is slowly disappearing.
The Xochimilo network of lakes and canals are suffering from pollution and the impact of urban sprawl in Mexico.
Biologists from Mexico’s Natural Autonomous University told reporters that they attempted to net the ‘walking fish’ for over four months in the muddy waters of Xochimilco, sampling ‘zero axolotls’.
Growing up to 30cm long, axolotol’s do survive in various aquariums and research labs around the world, but experts believe these environments do not provide ideal breeding ground and come with certain risks for the reptiles.
While biologists say it is too early to declare the species extinct, numbers of the reptile in the wild have dropped significantly. The Mexican Academy of Sciences 1998 survey recorded 6,000 axolotls for every square kilometre, that number dropped to 1,00 in 2003 and 100 in 2008.
Axolotls have short legs to drag themselves along the bottom of the lakes and tails which enable them to swim. They feed on crustaceans, aquatic insects and small fish.
However, an increase in illegal ‘shantytowns’ and residences in surrounding areas has resulted in untreated sewerage running off into the lakes water stream.
Mexican biologists will attempt another three-month search for the creatures, they hope to find some of what may be the last free roaming axolotol in the world.