Australian Marsupials Make Meal of Toxic Toads

A study has revealed that some small carnivorous marsupials in Northern Australia instinctively know how to avoid being poisoned by cane toads – Bufo Marinus. The University of Sydney’s Dr Jonathan Webb and his team have found that red-cheeked dunnarts from the Kimberley in Western Australia are naturally wary of cane toads.

The discovery was made when scientists trapped the dunnarts and filmed their first encounters with toads. The marsupials’ killer bites were aimed at the heads of the toads, avoiding their toxic glands and a likely death by poisoning. The research team found that the dunnarts quickly learn that eating other parts of the toad is dangerous. During subsequent encounters the “toad-educated” dunnarts sniff the toads from a distance before rejecting them. The results support another project being run by the team in the Northern Territory which uses cane toad sausages to teach endangered Northern quolls to avoid eating the poisonous amphibians.

The northern quoll – Dasyurus Hallucatus – is an endangered marsupial predator that was once common throughout Northern Australia. The major threat to northern quolls is the highly toxic cane toad that is currently invading northern Australia. Like other native predators, northern quolls lack physiological resistance to toad toxins, and consequently, most quolls die after attacking large toads. Since cane toads invaded northern Australia, quoll populations have plummeted, and the species faces extinction on the mainland. Cane toads cannot be eradicated, and they will soon invade Western Australia. Read the full article »»»»

Humans: Just Fish Out of Water

A study into the muscle development of several different fish has given insights into the genetic leap that set the scene for the evolution of hind legs in terrestrial animals. This innovation gave rise to the tetrapods — four-legged creatures, and our distant ancestors – that made the first small steps on land some 400 million years ago.

The team of Australian researchers led by Professor Peter Currie, of the Australian Regenerative Medicine Institute at Monash University, and Dr Nicolas Cole, of the University of Sydney, reports that Humans are just modified fish.

“The genome of fish is not vastly different from our own. We have shown that the mechanism of pelvic muscle formation in bony fish is transitional between that in sharks and in our tetrapod ancestors.” said Professor Currie.

Scientists have long known that ancient lungfish species are the ancestors of the tetrapods. These fish could survive on land, breathing air and using their pelvic fins to propel themselves. Australia is home to three species of the few remaining lungfish — two marine species and one inhabiting Queensland’s Mary River basin. Read the full article »»»»