The achoque is a critically endangered type of salamander.

There may be as few as 150 adults left in the wild and can only be found in Lake Pátzcuaro in Mexico.

Achoque face several potential threats including overfishing and pollution.

Scientists chipped a total of 80 salamanders - some in the UK at Chester Zoo and others from locations in Mexico, including a colony cared for by Dominican nuns.

The animals were monitored for four months and the chips had stayed in place and caused no long-term health impacts.

"Some species, we know that if we chip them they can be quite prone to just rejecting the chip out of the skin because amphibian skin is permeable so sometimes they can they can just reject things straight out of their skin. And this type of salamander, they can regrow their arms, they've got a very unique biology. So we were thinking well if we chip them, is it not just going to push it back out of its skin or almost like the body reacts like a healing process maybe? So we had to validate it by marking them," says Adam Bland, an amphibians expert at Chester Zoo who authored the study.

Now they have confirmed the technique works, it can be used on the wild population.

That will help answer critical questions about the species.

"It might be that by marking one and recording a location, we find that the salamanders actually move large distances around through the lake, or maybe they don't. We might find that there's a focal area of salamanders within the lake, and that can inform where to focus conservation and efforts for surveying the species. It can also help answer how long they live. Because we know based on in keeping them in zoos how long they can live, but that could be very different to how long a wild animal lives," says Bland.

Steps to protect the achoque salamanders could include banning fishing in areas of the lake where they breed and grow, removing the eggs and rearing them until they are too big to be eaten by invasive species, and improving drainage around the lake to reduce pollution.

But scientists still don't know how many Lake Pátzcuaro could support.

The study was published in JZAR, the Journal of Zoo and Aquarium Research.