It’s news that’s likely to send arachnophobes running for the hills: spiders have been observed eating fish. Don’t fret, they’re not working their way up the food chain. Although spiders are typically thought of as predators of insects, a team at the University of Basel, Switzerland and University of Western Australia has catalogued five families of spider that hunt fish in the wild.
“The finding of such a large diversity of spiders engaging in fish predation is novel. Our evidence suggests that fish might be an occasional prey item of substantial nutritional importance,” says study co-author Martin Nyffeler.
“Fish meat is high quality in terms of protein content and caloric value,” adds Nyffeler. “Feeding on fish may be particularly advantageous during the mating period, when the elevated energy and protein requirements of pregnant female spiders require increased food intake, or at times of limited availability of invertebrate prey.”
These semi-aquatic, fish-eating spiders typically live around the edges of shallow freshwater streams, ponds or swamps. A number of them are also capable of swimming, diving or walking across the water surface itself. They use potent neurotoxins to disable the fish and have powerful enzymes that enable them to digest fish up to twice their own size. The feeding process usually lasts several hours, researchers say.
But fear not: although fish-eating spiders can be found on all continents save for Antarctica, they are most prevalent in north America, particularly in the wetlands of Florida.