Living in a harsh, arid environment also means they must conserve resources, so they likely deliver only a tiny fraction of the contents of their glands each time they bite a prey animal. In nature, taipans need to kill their relatively dangerous rodent prey quickly, before it escapes or has a chance to retaliate. The fact that inland taipans specialise on rodents may partly explain their extreme toxicity to lab mice, but there's probably more to it that that. Why then is the inland taipan so toxic when it targets solely rodents? The precise answer to this question awaits further research, although it is possible to indulge in thought experiments. The evidence suggests that snakes evolve venom that is fine-tuned for the specific context in which it is used. Credit: Stewart MacdonaldĪt the molecular level, individual toxins have been identified that are 100-fold more toxic to natural prey than to laboratory organisms such as rodents. Rough-scaled snakes primarily feed on frogs. As these species are typically generalist feeders, this research has given us little insight into what has shaped the venom in the other species. Some are marine specialists, while others prefer eggs.ĭespite the opportunity this diversity represents to study venom ecology, the majority of venom research has focused on large species that are potentially dangerous to humans. Like all elapid snakes, the common ancestor of modern Australian species would have possessed a sophisticated venom system capable of delivering a complex cocktail of toxins into potential prey animals.Įlapid snakes quickly diversified in their new environment and today Australia is home to approximately 100 terrestrial species and more than 30 marine species – more than a third of the world's elapid snake fauna.Īustralian elapid snakes are extremely diverse in ecology and prey preference: some are general feeders that will tackle any prey, some prefer mammals, others frogs or reptiles. The family, which arrived in Australia some 10 million years ago, includes some of the world's most famous snakes such as the cobras of Asia and Africa and the mambas of Africa. The majority of snakes in this country are members of the Elapidae family, which means they have fixed fangs at the front of their mouths, and all are venomous. In Australia there is a unique opportunity to study the evolution of snake venom. Some snakes simply rely on powerful jaws while others feed on defenceless prey such as eggs, so have no need of any additional deadly method of subjugation. Many snakes use constriction, as dramatically demonstrated in the recent battle between a python and crocodile in Queensland. There are no herbivorous snakes, but venom is not the only way that snakes can subdue their prey. That not all snakes developed sophisticated venom delivery systems suggests that being highly venomous is not always the most efficient way for a snake to secure a meal.

This means that all snakes had an equal evolutionary opportunity to become venomous. We do know that the common ancestor of all snakes possessed a rudimentary venom system. We also do not know how diet influences its composition – the ecology of venom is an almost completely neglected area of research. These are important goals for venom research, but the result of this bias toward human interest is that we still know very little about the ways in which snakes use their venom in nature. This has allowed us to learn more about human physiology and to search for compounds that may be useful in drug design, such as the toxin from the venom of a pit viper from which the blood pressure medication Captopril was developed. Most attention has been given to the development of antivenom and to studying the building blocks of toxic proteins found in snake venoms. Large species of venomous snake, those that are known to be potentially dangerous to humans, have received the lion's share of attention. Historically, the focus of snake venom research worldwide has been anthropocentric – examining the impact the venom has for humans. We know almost nothing about the evolutionary selection pressures that have refined and enhanced the toxins present in the venom of this iconic species of snake. What we don't know, though, is why the inland taipan needs such toxic venom. Effective antivenom also exists for the treatment of bites. The venom of the inland taipan has attracted considerable research interest and the toxins responsible for its extreme toxicity have been identified. Astonishingly, a single bite from an inland taipan is capable of delivering enough venom to kill 250,000 lab mice.

The snake that holds the popular title of ' world's most venomous' is the inland taipan ( Oxyuranus microlepidotus), an inhabitant of Australia's arid interior.

Inland taipan fangs