Cat and Mouse

Australia has long been known for its impressive and deadly array of wildlife. From huge saltwater crocodiles to venomous funnel-web spiders, it seems as though there’s always a surprise lurking in every river and behind every bush. Even the comical-looking platypus hides a fearsome set of venomous spurs on its heels, so it’s safe to say that Australian creatures are best approached with a measure of caution, no matter how harmless they may seem.

Yet scientists were nevertheless surprised when they examined the feeding habits of catfish in Western Australia’s Ashburton River, and discovered that they were helping themselves to far more than the occasional bug or larva. After studying the stomach contents of a number of Blue Salmon Catfish (Neoarius graeffei), the scientists were amazed to find that nearly half of them contained the remains of Hopping Mice – a common resident of Western Australia’s arid regions. What’s more, the stomachs they examined were over 90% full of nothing but mice, showing that the fish had well and truly helped themselves to a proper rodent feast.

While it was previously theorised that freshwater fish in the region might occasionally predate on mammals, it was thought to be an infrequent, opportunistic behaviour. However, this latest evidence has proved beyond a doubt that rather than just being an occasional catfish snack, the unfortunate mice are in fact a significant, deliberate and important part of the catfishes’ diet.

It’s not yet known just how the catfish manage to hunt mice so successfully, but scientists currently believe that no matter how they do it, they’ve found a way to make use of an important and readily available source of energy. One thing that is very clear though, is that mice can never seem to catch a break and that cats will be cats the world over – even when they’re fish...