The panther chameleon is known for its remarkable ability to shift its skin colour through a rainbow of vibrant reds, greens, blues and yellows.

The range of the lizard's colour palette has bewildered scientists, as it seems too amazing to be possible for a single species.

Now scientists have figured out the chameleon's secret — it isn't a single species. There are actually 11 species of panther chameleon, each with its own unique colour patterns, scientists reported in a recent issue of the journal, Molecular Ecology.

A team of researchers led by Michel Milinkovitch, a professor at the University of Geneva (UNIGE), was trying to understand the genetic key behind the panther chameleon's ability to change through such a vast range of colours. They took photographs of and collected drops of blood from 324 panther chameleons during two expeditions to the northeastern region of Madagascar.

An analysis of DNA collected from the blood samples revealed surprising genetic diversity.

"It was a a mix of something that was [and was] not totally expected. We started these studies because we were thinking there was something interesting there. So it was not completely out of the blue," Milinkovitch says.

Mathematical analysis

The different species of panther chameleon seemed to be restricted to specific geographic locations in Madagascar, indicating that there was not much interbreeding. Milinkovitch and his team wanted to know if there was a link between the colour of each individual lizard and its species, so they looked at the colour photographs to try to detect a pattern.

Mathematical analysis allowed the research team to develop a classification key that associates the combination colours of each panther chameleon's lips, face, vertical bars and body background to one of the 11 species. (Michel Milinkovitch)

"This was not that simple. There is a lot of variation [in colour for each species], so we had to resort to complicated mathematical analysis of colour variation," he says.

The results of the mathematical analysis allowed the research team to develop a classification key that associates the combination colours of each panther chameleon's lips, face, vertical bars and body background to one of the 11 species. According to Milinkovitch, by using the key, they can "correctly assign 85 per cent of the [panther chameleons to their species] simply by looking at the picture" and comparing it to the lizard in nature.

The classification key is important for the conservation of the panther chameleon population as deforestation becomes increasingly problematic for the island's ecosystems and the species' presence on Earth. Human activities are threatening hundreds of animals, thousands of plants and countless invertebrate species on the island. To make matters worse, the panther chameleon, along with 80 to 90 per cent of the flora and fauna in Madagascar exist nowhere else on the planet.

Although the researchers from UNIGE have contributed to the understanding and potential conservation of the colourful panther chameleon species, Milinkovitch says this is only the beginning.

"Now taxonomists have a lot of work."

Scientists will have to look at all of the physical and behavioural traits of the new species, along with genetic information, to confirm the exact number of panther chameleon species.