WA's bamboo sharks at US festival

Survival of the Stillest: Predator Avoidance in Embryonic Bamboo Sharks by Ryan Kempster.

A Perth researcher’s short film about embryonic bamboo sharks has been selected to screen at a prestigious US film festival.

Survival of the Stillest: Bamboo Sharks, filmed by University of WA shark biologist Ryan Kempster, includes footage of a shark foetus in an egg case slowing its heartbeat and lying perfectly still to avoid detection by predators.

The three-minute movie was filmed entirely in an aquarium on the UWA campus and also has vision a baby bamboo shark hatching out of an egg case.

Mr Kempster said developing shark embryos were able to detect predators with their electrosensory systems.

“When you present them with an electric field that mimics that of a predator, so a larger fish, the embryos will actually detect this and stop all of their body movements,” he said.

“They stay completely still, stop respiring… this really is their way of minimising being noticed by a predator.”

Mr Kempster compared the shark’s stage of development in the egg case to unborn human babies.

“When they’re growing in the egg, it’s effectively the equivalent of when we’re developing inside our mother,” he said.

“If you think of it in that respect, can you imagine us as a baby actually being able to respond to external stimuli?”

Mr Kempster said bamboo sharks developed in the egg case for up to five months before hatching when the case reached about 12cm long.

He said the embryos were at risk of being eaten by almost “anything that can fit it in their mouth”.

“You generally find large gropers and sharks will predate on the embryos and it’s even possible that the mother could predate on her own young,” Mr Kempster said.

Fully grown bamboo sharks can reach 1-1.2m long.

Mr Kempster said he was very surprised to have his movie selected for the film festival alongside the work of professional documentary makers.

“I really didn’t think I had a chance to be honest,” he said.

The film will be screened at the Beneath the Waves Film Festival in Virginia on Friday and Saturday.