A new research paper just published in the scientific journal Plos One brings us new fuel for nightmares: Spiders not only eat other insects but also kill and eat fish often much larger than them. And it's not only one or two species but many species at a global scale.
More than 80 incidences of fish predation by semi-aquatic spiders -- observed at the fringes of shallow freshwater streams, rivers, lakes, ponds, swamps, and fens -- are reviewed. We provide evidence that fish predation by semi-aquatic spiders is geographically widespread, occurring on all continents except Antarctica.
Spiders wait on the edge of the water, with a couple of legs on firm ground and the rest resting on the water thanks to its surface tension. They wait for a fish to pass, attack, inject a powerful venom that paralyses them, and then drag them to dry land and start to process them.
Most of the cases have been observed in North America, especially in the wetlands of Florida.