These Astounding Spiders Actually Catch and Eat Fish
Sat, 21 Jun 2014 10:05:42 PDT
By now we know that spiders aren’t to be trifled with—and not just because their eight eyes or spindly fuzzy legs can give anyone the creeps. Now we can add another bullet point to the arachnid’s ever-growing skillset: capturing and eating fish twice their size.
A new study published in PLOS ONE reports that spiders have been preying on fish two to six centimeters in length—roughly 2.2 times the arachnids’ size—to boost their diet of small insects.
The predators’ MO? Sit on a rock or a plant and dip their front legs in the water. When an unwitting fish’s fin touches a leg, the spider lunges to bite the cold-blooded vertebrate (usually at the base of the head). Once the fish dies from venom, it’s dragged to a dry place and then eaten.
"You would think that there was a much higher risk of a spider being damaged in that ensuing conflict, but there's a really significant payoff,” explained Bradley Pusey, a co-author of the study, to ABC Science. “It's a big-ticket food item with lots of protein and flesh to consume, whereas an invertebrate has lots of hard material that the spider discards."
“This requires a lot of flexibility in hunting strategy,” he said.
But the behavior, though discovered to be more widespread than previously thought, didn’t exactly shock the scientists.
“Despite the widespread assumption of spiders primarily being insectivores, piscivory [fish eating] is not all together surprising,” wrote the study’s authors, “considering that a number of spiders… occasionally supplement their arthropod diet with small vertebrates including frogs, toads, salamanders, lizards, snakes, mice, rats, bats, and birds.”
These types aren’t rare either. The fish-munching semi-aquatic group includes eight spider families that have been known to live in shallow waters on every continent except Antarctica. The arachnids are very common on the eastern coast of the United States, especially in Florida’s freshwater wetlands. Researchers have also recorded the predatory behavior in garden ponds in Australia.
Scared? Besides scientists who observe spider behavior, few witnesses have documented fish-eating incidences. (Other than photographs, no video evidence could be unearthed as of this writing.) Plus, it’s all part of the ecosystem. Spiders may sound more menacing with each new research, but they also serve as a major food source to birds, lizards, and other critters. Species of hummingbirds and caterpillars rely on arachnid silk to build nests. And, unfortunately, deforestation and agriculture threaten the arthropods along with many invertebrates.
“There are lots of other things that would be riskier for your goldfish,” Pusey told ABC Science, “but you never know.”
Related stories on TakePart:
• Mixing Spider DNA and Goat Embryos Produces Milk With a Side of Silk
• What’s Smarter Than Google? Oh, Just Your Average Ant Colony
Original article from TakePart
