It's a cat and mouse game like you've never seen before.
Researchers studying a population of catfish in Western Australia have been caught eating live mice – but no one really knows why.
The team from Murdoch University caught 18 lesser salmon catfish (Neoarius graeffei) from Western Australia’s Ashburton River, as part of an investigation into Australian native catfish populations.
When they opened up the stomachs of the fish to explore their diets, 44 percent of the stomachs contained spinifex hopping mice (Notomys alexis)
A spinifex hopping mouse recovered from the stomach of one of the catfish [Image: Dr Erin Kelly, Murdoch University]
While it’s been reported that certain European catfish deliberately breach themselves to capture land-based prey, it appears that these Aussie catfish are staying in the water – and their prey is sticking to the land. The question of what’s going on has scientists perplexed.
Lead researcher Dr Erin Kelly, from the Centre for Fish and Fisheries Research, said it was likely the catfish were opportunistically gaining access to the mice.
“Dryland rivers experience extreme cycles of drought and flooding, which leads to a great variation in the type and amount of food available at certain times,” said Dr Kelly.
“The catfish may be altering their diets according to what’s available. This mouse species has been reported to construct deep burrow systems in the sand of riverbanks. If a burrow of mice is flooded and collapses into the river, the catfish are likely to be taking advantage.
“Both species are nocturnal, and it is also possible that the catfish are actively hunting mice on the riverbank.”
A paper on Dr Kelly’s research has been published in the Journal of Arid Environments and can be read here.