Catfish Gotta Catch Them All
Great. First we found out catfish were eating pigeons. Now they're eating mice. Who's next? Us? Remember that scene in the shark attack classic DEEP BLUE SEA, when Samuel L. Jackson's making a big speech next to a pool and then a shark leaps out and swallows him whole? I don't know if sharks can really do that… but catfish sure can, according to a recent study in the “Journal of Arid Environments.” Catfish in Australia have been consuming mice. A lot of mice. And no one knows how. We're specifically talking about the lesser salmon catfish here, in the Ashburton river in northern Australia. When researchers cut open 18 of these bad boys, half of them had Spinifex hopping mice in their bellies.
This is the first report of Australian catfish eating land-based mammals at this high of a rate, though previous studies had found similar mammals to be about 4% of the catfish's diet. These “lesser” salmon catfish are common in north-western Australia and can weigh just over 3 pounds and measure more than one and a half feet. 44% of the 18 fish sampled here had mice in them. And of those, mice made up 95% of what was in their tummies. Two of them had three mice each inside! But they usually eat insects, crustaceans and plants. Fish eating terrestrial mammals is possible, but usually infrequent.
The hopping mice getting eaten don't usually hang out by the water, and they're good at jumping… so how are they getting eaten by catfish? Well, one possibility is the catfish are actively hunting mice on a riverbank. It sounds crazy, but a 2012 study showed that a larger catfish species was beaching itself so it could attack and eat pigeons, even though this stunt risked it being trapped on land. Similarly, African tigerfish will jump up and pull other birds underwater for a meal. In the case of the pigeons, researchers thought it resulted from the catfish adapting to a new environment to survive. Maybe the same thing's happening here? Another possibility, and the researchers' best guess, is that last year's extreme summer rainfall flooded the burrows of these mice, pushing them into the river. Since these floods could be throwing the local ecosystem off balance, the team wants to investigate further to find out exactly what's happening. While the findings suggest that lesser salmon catfish will consume large quantities of land mammals whenever available, thankfully we can't fit down their mouths.
This is the first report of Australian catfish eating land-based mammals at this high of a rate, though previous studies had found similar mammals to be about 4% of the catfish's diet. These “lesser” salmon catfish are common in north-western Australia and can weigh just over 3 pounds and measure more than one and a half feet. 44% of the 18 fish sampled here had mice in them. And of those, mice made up 95% of what was in their tummies. Two of them had three mice each inside! But they usually eat insects, crustaceans and plants. Fish eating terrestrial mammals is possible, but usually infrequent.
The hopping mice getting eaten don't usually hang out by the water, and they're good at jumping… so how are they getting eaten by catfish? Well, one possibility is the catfish are actively hunting mice on a riverbank. It sounds crazy, but a 2012 study showed that a larger catfish species was beaching itself so it could attack and eat pigeons, even though this stunt risked it being trapped on land. Similarly, African tigerfish will jump up and pull other birds underwater for a meal. In the case of the pigeons, researchers thought it resulted from the catfish adapting to a new environment to survive. Maybe the same thing's happening here? Another possibility, and the researchers' best guess, is that last year's extreme summer rainfall flooded the burrows of these mice, pushing them into the river. Since these floods could be throwing the local ecosystem off balance, the team wants to investigate further to find out exactly what's happening. While the findings suggest that lesser salmon catfish will consume large quantities of land mammals whenever available, thankfully we can't fit down their mouths.
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