Gilgie survived long walk

The sandpit in forest off the Preston Road is at least a kilometre from the Collie River. It is just off the old road into the former Wyvern and Phoenix underground coal mines, opposite Minninup Pool.

The crustacean’s finder contacted river campaigner Ed Riley about the find. Both said larger marron could travel considerable distances overland but the distance from river to sandpit should have been beyond a small gilgie.

It was dead when found, apparently having perished when the excavated sand heated up and dried in the trailer.

Mr Riley pointed to paperbacks edging the sandpit, as an indication of moisture, and suggested the gilgie might have emigrated via that route during a wetter winter and buried itself to aestivate (like hibernation but in summer instead of winter).

Dan Machin, of Cherax Park Aquaculture, who advised on setting up Collie Valley Marron, said the distance seemed unusual.

Gilgies have gills under their heads and on a moist overcast day they could travel surprisingly long distances, he said. But those long distances could be measured in hundreds of metres, not a kilometre. “I have not heard of distances of that order,” Mr Machin said. “Usually they would be picked off by birds,” he explained.

“Physically it is possible but it was a miracle it avoided birds or desiccation,” he said.

Murdoch University researcher, Dr Stephen Beatty, said there had been no research on how far WA species of crustacean could travel. Most of what he knew was anecdotal reports from marron farmers.

But there were examples in overseas countries of crayfish travelling several kilometres.

Gilgie size was not really an issue because gilgies were generally more hardy than marron, Dr Beatty said. “They live in places that dry up,” he pointed out.

Marron move when their water disappears.

Dr Beatty believed a one-kilometre hike was quite possible for a gilgie. “But you can say it is a record for a gilgie as far as I am concerned.”