Most people worry about spiders biting but it turns out that some spiders think about bites too – not by other spiders or nervous humans but by fish. A new study has found that a few species of spiders like to go fishing and fish-eating arachnids are trolling the waterways of every continent except Antarctica.
Arachnologist Martin Nyffeler of the University of Basel in Switzerland and fish ecologist Brad Pusey of the University of Western Australia recently completed a census of spiders that feed on fish. Their total – 89 – and their interesting findings are published in the journal PLOS ONE. Nyffeler is an expert on arachnids with unusual non-insect diets, having previously published studies on spiders eating earthworms, slugs and bats.
Using eyewitness reports, photos and research, Nyffeler and Pusey counted at least 18 different spider species from five families (Pisauridae, Trechaleidae, Lycosidae, Ctenidae and Liocranidae) that were observed catching fish in the wild and six species (including ones from the Cybaeidae, Desidae and Sparassidae families) seen snacking on seafood in a lab.
Most live in warm climates and all limit themselves to freshwater fish, such as catfish in Ecuador, killifish in Cameroon and mosquitofish in Florida. While found everywhere but Antarctica, the highest concentrations of fish-eating spiders are in Florida and Central and South America.
How exactly do they catch the fish? Pusey explains:
The spider typically assumes a position near the water's edge, with the rear pair of legs anchored to some vegetation or wood or rock, and their three front pairs of legs out of the water's surface.
When the spider feels a fish touch a leg, it jumps in and bites it, injecting neurotoxins to kill or stun it. It then drags the fish out of the water and eats it raw – no need for tartar sauce or wasabi.
Unfortunately, many of these fish-eating spiders are endangered because of disappearing wetlands.
No word on whether too many weekend fishing trips is a reason why black widows eat their mates.