The little spiders I find hiding in the corners of a room or hanging out among the plants outside my front door are usually fascinating little creatures — and nothing to be frightened of. Those spiders are usually insectivores and not interested in anything with a backbone, let alone a full-grown human.
But insect eaters aren’t the only kinds of spiders out in the wild. There’s a whole category of spiders that hunt for their meals rather than sit and wait for something to get caught in a web. And I will admit that a new review of hunting spiders that eat fish creeped me out. (Weird, I know.)
Spiders are mostly thought of as land dwellers that build webs to catch flying insects. However, there are actually a number of amazing spiders species that have adapted to aquatic environments and feed on fish and other water creatures.
These semi-aquatic spiders employ clever hunting techniques to prey on animals much larger than themselves. Their specialized adaptations allow them to walk on water, detect vibrations, dive and swim after prey.
Here are 8 of the most fascinating fish-eating spiders from around the world and how they manage to catch their unlikely victims
1. Fishing Spiders
Fishing spiders belong to the genus Dolomedes, with over 100 species found globally. They live along the edges of ponds, streams, swamps and other calm freshwater.
These spiders have water-repellent hairs on their legs that enable them to sprint across the water’s surface to ambush insect prey or pursue small fish and tadpoles. They sense vibrations through their legs to pinpoint potential prey movements. Some species will dive below the surface or swim short distances to catch food.
The dark fishing spider Dolomedes tenebrosus is one of the more common fishing spiders in North America. Females can grow up to 1 inch long and will fiercely defend their egg sacs from predators.
2. Giant Fishing Spider
The giant fishing spider Dolomedes okefinokensis, found in Florida wetlands, is one of the largest fishing spider species. The body length of mature females reaches over 1 inch.
These huge spiders prey on aquatic insects, frogs, turtles and small fish. Their legs allow them to sprint rapidly across the water to seize vertebrate prey at the surface. They inject venom to subdue the animal before carrying it to land to eat.
3. Diving Bell Spider
The diving bell spider, Argyroneta aquatica, is the only truly aquatic spider. It lives its entire life underwater, only surfacing briefly to replenish its air supply.
This spider spins an underwater web shaped like a diving bell, filled with air. The spider will rest, mate, lay eggs and hibernate inside its diving bell. It emerges to hunt for fish, tadpoles and aquatic invertebrates.
The diving bell provides oxygen for the spider to breathe while remaining submerged for up to 24 hours. Some spiders construct underwater silken “air tubes” leading to the surface.
4. Fishing Huntsman Spider
Huntsman spiders in the Heteropoda genus, found in Asia, also exhibit fishing behaviors. Their speed and venom make them adept at seizing fish and other small aquatic animals.
Heteropoda natans is a tropical species that hunts around the edges of freshwater ponds and streams. These aggressive spiders will plunge beneath the surface to catch tadpoles, but also feed on many insects.
5. Ancylometes Fishing Spiders
The Ancylometes genus contains around 70 species found in tropical regions of the Americas. These wandering spiders can walk and run across the water’s surface thanks to water-repellent hairs.
Ancylometes rufus is known to eat small fish in addition to insects, scorpions, lizards and frogs. They can remain submerged underwater for up to 20 minutes by trapping air in the hairs on their abdomen.
6. White-Flanked Fishing Spider
Nilus albocinctus is a fishing spider found across Asia in freshwater habitats. The distinctive white bands on its otherwise dark body make it easy to identify.
This spider anchors itself in vegetation at the water’s edge. It spreads its front legs across the surface to detect vibrations of potential prey. It can swim down to catch small fish and tadpoles.
7. Raft Spiders
Raft spiders in the genus Dolomedes are widespread in Europe and noted for their ability to travel across wide stretches of water. Their buoyant bodies enable them to float on the surface if swept away from shore.
Dolomedes fimbriatus hunts tadpoles and small fish in addition to insects. It will dive below the surface to catch prey but carries it back to dry land before feeding. Raft spiders can run rapidly across the water without breaking the surface tension.
8. Fishing Huntsman Spiders
The giant fishing spider Ancylometes bogotensis, ranging from Central America to Brazil, grows up to 4 inches long. Despite their scary appearance, these spiders are not aggressive toward humans.
They inhabit rainforest streams and rivers, preying on aquatic insects, small crustaceans, fish and frogs. Their diving abilities allow them to remain underwater for up to 35 minutes while hunting.
Hunting Adaptations
Fish-eating spiders employ incredible adaptations and strategies to hunt prey larger than themselves in an aquatic environment. These include:
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Water-repellent hairs that allow them to sprint across the water’s surface.
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Sensitive leg hairs that detect the slightest vibrations from swimming prey.
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Excellent underwater vision to spot prey while diving.
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Ability to dive and swim short distances below the surface.
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Injecting venom to quickly immobilize aquatic prey.
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Carrying fish to dry land before feeding to avoid water dilution of venom.
So while we don’t typically think of spiders and fish as interacting, there are clearly some remarkable spiders species that have mastered the art of piscivory! Their ingenious techniques demonstrate how evolution shapes animal behavior.
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Scientists have come across fish-eating spiders from time to time. The review, published June 18 in PLOS ONE, tallies up these arachnids for the first time. For their study, Martin Nyffeler of the University of Basel in Switzerland and Bradley Pusey the University of Western Australia in Albany searched through the scientific literature, perused the Internet and asked biologists about any unpublished findings to get as full a census as possible.
They found that fish-eating spiders come from several different families and genuses and can be found on every continent but Antarctica. But they’re more common between 40 degrees north and south latitude. Most are semi-aquatic and live on the edge of water bodies, like streams, lakes and swamps. There was one exception: the world’s only known completely aquatic water spider, Argyroneta aquatica.
Exactly how the spiders catch the fish isn’t quite clear. But some of the fish may simply be unlucky — they get close enough to brush by a spider’s leg and trigger an attack. Death comes through venom, injected through large, piercing chelicerae, usually at the base of the head. Most die within a few seconds to minutes. Larger fish can linger for nearly an hour. To consume its meal, the spider has to find a dry spot (the aquatic arachnids find a pocket of air among underwater vegetation) where it can pump their prey full of enzymes that will digest it.
These spiders are usually going after the most common fish found in their neighborhood, and they aren’t just attacking the small fry. On average, a spider’s prey is 2.2 times as long as the arachnid. (And this is where my nightmares started — some of these spiders are huge: The South American Ancylometes rufus, for example, has a leg span of 20 centimeters and is bigger than my hand.) And spiders in the genera Dolomedes and Nilus have been spotted catching fish that are 4.5 times heavier than themselves.
But none of these spiders would seem to be a threat to vertebrates as large as us. Even so, and even though I consider myself to be pretty low on the arachnophobia spectrum, there’s something about fish-eating spiders that I fear might make its way into my dreams.
This Terrifying Spider Hunts Fish Underwater
FAQ
What kind of spiders eat fish?
Dolomedes /dɒləˈmiːdiːz/ is a genus of large spiders of the family Dolomedidae. They are also known as fishing spiders, raft spiders, dock spiders or wharf spiders.
Why is a fishing spider in my house?
Habitat: Prefers wooded areas. Lives in and around swimming pools, entering homes through cracks in damaged foundations.
Are fisher spiders poisonous?
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Not a Significant Threat:Fishing spider bites can cause temporary pain and discomfort, but they are not medically significant.
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Venom:Fishing spiders do have venom, but it’s not strong enough to pose a serious threat to humans.
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Bites:They rarely bite, and when they do, the bites are typically no more severe than a bee or wasp sting.
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Avoidance:Fishing spiders tend to avoid humans and will flee at the slightest movement.
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Ecological Role:They play an important role in controlling aquatic insects.
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Appearance:Fishing spiders are large, fast, and can even dive underwater to catch small fish.
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Habitat:They are often found near water or in wooded areas.
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This species is more frequently associated with wooded areas and is a common household invader in those locations.
Do spiders eat fish?
Yes, spiders do eat fish. Some spiders can consume prey that is several times their size. In this article, we’ll explore how spiders hunt and eat fish, and highlight some of the most interesting species of fish-eating spiders.
What else do fishing spiders eat besides insects?
Fishing spiders mainly prey on insects but also seizes tadpoles and small fish. From its vantage point above the water, it senses underwater prey swimming close by, and grabs it with its powerful front legs.
Where have fish-eating spiders been observed?
At least 18 species have now been observed catching fish, including six-spotted fishing spiders (Dolomedes triton) in the United States, pond wolf spiders (Pardosa peudoannulata) in India, and great raft spiders (Dolomedes plantarius) in the United Kingdom.
What eats fishing spiders?
The main predators of fishing spiders are birds and snakes. Dragonflies have also been observed catching young spiders. Species parasitic on the spiders include a wasp of the Pompilidae family, commonly called the Spider Wasp, that stings the spider to paralyze it before carrying it off and laying an egg in its abdomen.
Do spiders catch fish?
Yes, there are spiders that catch fish. At least 18 species have been observed catching fish, including six-spotted fishing spiders in the United States, pond wolf spiders in India, and great raft spiders in the United Kingdom.
Are there fish-eating spiders in the world?
Yes, you read that right, there are fish-eating spiders in the world. In this article, you’ll get to know all about these fascinating arachnids and their unique hunting habits. These spiders belong to a group known as fishing spiders, with most of them belonging to the genus Dolomedes.