Fresh Science

Many pet snakes are venomous!

Big trouble for the global pet trade in snakes.

Dr. Bryan Grieg Fry of the Australian Venom Research Unit at the University of Melbourne has discovered that the number of venomous snakes in the world is not around 250 but actually closer to 2700.

In his research into the evolution of snake venom, he discovered that venom goes back much further than previously thought.  ‘Snake venom developed only one time in evolution, a few hundred million years ago,’ he says.

‘The first venomous snake evolved from the heavy bodied swamp monsters similar to the anacondas of today.  They needed a new tool to kill their prey since they were trading in the heavy muscle in order to become quicker and more athletic.  Enter venom. They used this venom to feed on the cute little furry rodents that eventually became us.’

“This origin of venom is so far back, that it occurred before the snake we commonly think of as ‘non-venomous’ even showed up on the tree of life.  I realised that some of the ancient venom may still be produced by them today.  So I started looking at non-venomous snakes. And when I looked at a ratsnake, the archetypal non-venomous snake, I isolated typical cobra-style toxin.”

It’s a stunning discovery that will send shockwaves through the international pet snake trade. Some non-venomous snakes have been previously thought to have only mild ‘toxic saliva’ but Dr. Fry has shown that it is a true venom. Dr. Fry’s research has shown that some of the snakes common in the overseas pet market actually produce highly potent venoms.

The pet trade has had problems with non-venomous snakes actually turning out to be highly venomous.  In the late-70s/early 80s, some of the most popular snakes in the US pet trade were the Asian keelback snakes.  These snakes turned out to be highly venomous. Several children were bitten and became severely ill.

“My research now shows that the vast majority of the snakes commonly kept as pets are actually venomous. Are all these species dangerous?  Certainly not,” Bryan says.

‘Are there highly venomous species lurking in the petshops that we don’t know about?  Definitely. I’ve consulted to two US petshops where employees were paralysed after being bitten snakes thought to be totally harmless.

It’s not a big issue for petshops in Australian where the trade is well regulated, and we know that most Australian snakes are deadly. But the discovery will cause shockwaves and a legislative storm in the United States and Europe.

In the search for further evidence, Bryan has scoured the world for these unique venom samples. “In 2002 alone, I milked over 2,000 snakes from quite a few countries. I caught them by exploring caves, climbing trees and doing ultra-deep scuba dives. It was extreme science at its best and I had a complete blast doing it,” sys Bryan.

However, this dark storm cloud over the pet trade actually has a silver lining – a new resource for biotechnology. The ratsnake venom is an excellent candidate for use as a laboratory tool or even as a scaffold for use in drug design and development.

Bryan Fry

Research Fellow Australian Venom Research Unit

Ancient Venom

Molecular evolution of snake venoms.

Dr. Fry, who is fascinated by venomous snakes and venom evolution, has made the ground breaking discovery of what the very first venomous snake had in its venom. On the side he also found out, sometimes the hard way, that many common ‘non-venomous ‘ pet store snakes are actually as venomous as a cobra!

Project description

“Madagascar is our Galapagos Islands and the snakes are our finches “says Dr. Bryan Grieg Fry from the Australian Venom Research Unit at the University of Melbourne. During a study on the evolution of venoms in Australian snakes, Bryan noticed that the toxin diversity was giving the impression that the venoms had been evolving a lot longer than the snakes themselves. To test this theory he analysed the ‘saliva ‘ of an archetypal ‘non-venomous’snake, the ratsnake, to see how far back venom components started in the evolution of snakes. The ratsnake, which is commonly sold in pet stores, shockingly contained the same toxins as a cobra or death adder, and the toxins were just as potent!

Intrigued, Bryan scoured the world for representatives of the major snake lineages. Being an expert in venomous snake handling, he collected and milked the majority of the snakes studied. In 2002 alone, he milked over 2,000 snakes, was envenomated four times (including a cobra bite) and got bent while diving for sea snakes in the remote South Pacific Islands. The Madagascar snakes, separated from all other snakes for between 40 to 150 million years, proved to be the crown jewel in this story of ancient venom. In comparing the venom from these unique and evolutionarily isolated snakes with all the other major lineages across the world (the ‘non-venomous ‘snakes, the elapids and the vipers) he was able to determine the toxins that they all shared in common. When traced against the tree snake of evolution, he is able to present the venom of the very first venomous snake.

The implications of this study reaches far and wide into the scientific community, with the number of snakes containing venom being increased from 250 to ~2700! Bryan ‘s work has revealed a vast venomous Serengeti of unstudied toxins for toxinologists. The medical community may benefit through using unique, and up until now unknown, toxins to explore actions and reactions in the human body, even potentially leading to new drugs. Biologists and erpetologists also get a shake up as snake taxonomy readjusts itself around the idea of most snakes being venomous and having access to what was in the primal venom.

Personal details

Qualifications: Ph.D. University of Queensland (Institute for Molecular Bioscience/Department of Biochemistry), 2002.

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