Spiders That Eat Fish: Unveiling Aquatic Predators

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Did you know that some spiders are capable of catching and eating fish? 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. They live near water and are known to catch small fish and aquatic insects as they walk on the water’s surface. One interesting species you might come across is the dark fishing spider (Dolomedes tenebrosus), which is more frequently found around wooded habitats.

So, how do these spiders catch their prey? Fishing spiders have good vision, and they’re quite aggressive hunters. They use their specialized legs to walk on the water’s surface, sensing vibrations of potential prey, and then swiftly attacking. Some species are even capable of diving underwater to catch their meal. In the next sections, we’ll dive deeper into the fascinating world of fish-eating spiders and their unique abilities.

Spiders That Eat Fish: A General Overview

Fishing Spiders

Fishing spiders, specifically species in the genus Dolomedes, are known for their water-dwelling habits. These spiders live near water and are capable of catching small fish and aquatic insects. They are often large and similar in size, shape, and coloration to wolf spiders.

Hunting Techniques

These spiders have unique hunting techniques, such as running across the water’s surface. Although some build webs, others, like the spotted fishing spider, do not use webs and prefer to rely on their agility and speed to catch prey.

Habitat and Behavior

You can usually find fishing spiders near water sources, such as ponds or docks. Their peak activity occurs from May through September in certain regions, and they are known to hibernate during colder months.

Features of Fishing Spiders:

  • Live near water
  • Catch small fish and aquatic insects
  • Similar to wolf spiders in appearance
  • Run across water’s surface
  • May build webs or not, depending on the species
  • Hibernate during colder months
  • Active during warm months (May through September)

Lastly, remember that while these spiders can catch and eat fish, they are not dangerous to humans. Approach them with curiosity and respect, and you’ll have a fascinating learning opportunity.

Geographical Distribution of The Fishing Spider

Fishing spiders, belonging to the genus Dolomedes, can be found in various parts of the world. They usually live near water, making locations like the wetlands of Florida suitable habitats. These spiders can be found on all continents, except for Antarctica.

For example, in the US, you can spot fishing spiders near lakes, rivers, or ponds. Similarly, in Australia, they reside near water bodies where they can find small fish, insects, and other prey. In warmer climates, you are more likely to encounter these spiders, whereas in colder regions such as Switzerland, their presence may be less common.

Fishing spiders prefer living in environments with diverse ecosystems. South America and Asia offer such habitats, giving them the opportunity to thrive in these areas. Wetlands, forest edges, and pond margins are some common places where you can find them. However, you are unlikely to spot them in Antarctica, as this region does not provide the suitable conditions they need for survival.

To give you more clarity on where to find fishing spiders, here’s a brief overview:

  • US: Common near water bodies
  • Australia: Found near lakes, rivers, and ponds
  • South America & Asia: Thrive in diverse ecosystems near water
  • Switzerland: Less common due to colder climate
  • Antarctica: Not found due to unsuitable conditions

In conclusion, if you’re searching for fishing spiders, focus on areas near water bodies with warmer climates and diverse ecosystems. Remember to respect their natural habitats and observe them from a safe distance.

Understanding the Predation Process

The Hunt

Fishing spiders are arachnids that exhibit a unique hunting technique when it comes to capturing small fish. Unlike many other spider species, they do not rely on webs to catch their prey. Instead, fishing spiders use their keen senses of vision and vibrations to detect any potential targets. They primarily hunt near the surface of the water, where small fish swim close by.

While you might be familiar with most spiders being land predators, these arachnids excel at underwater pursuits as well. Fishing spiders display great agility and can even dive below the water’s surface to chase their prey.

The Catch

When a fishing spider identifies a potential meal, it will make use of its specialized legs to swiftly ambush the unsuspecting fish. They can expertly balance on the water surface, using their legs to propel themselves across it. This allows them to firmly grab the fish, sinking their fangs with precision. By injecting venom filled with neurotoxins and digestive enzymes, they immobilize their victims and start the digestion process.

The Digestion

The digestive process for fishing spiders begins with the venom breaking down the fish’s tissue, making it easier to consume. Over time, the enzymes continue to soften the fish, with the spider consuming the liquefied tissue. The spider does not swallow or chew the fish but instead absorbs its nutrients directly.

Though these fish-eating spiders are not a danger to humans, their hunting techniques and predation process showcase the versatility of arachnids as predators. As you can see, they have adapted to various environments, including underwater ones, to satisfy their dietary needs.

Species of Fish-Eating Spiders


Dolomedes, also known as fishing spiders, belong to the family Pisauridae. These spiders are usually found near water and catch small fish and aquatic insects. Some common species include:

  • Dolomedes tenebrosus: more frequently found away from water
  • Dolomedes triton: the spotted fishing spider, living in aquatic habitats

Fishing spiders have impressive features such as:

  • Large size, similar to wolf spiders
  • Ability to run across the water’s surface
  • Front legs reaching out to detect vibrations from prey

Their diet consists of more than just fish, as they also feed on:

  • Dragonflies
  • Mosquitofish
  • Other insects

Females of this genus are known for their bold behavior and predation abilities.


Ancylometes is another genus of fish-eating spiders belonging to the family Ctenidae. They are commonly found in:

  • South America
  • Central America

These water spiders are known to prey on small fish, such as goldfish and nilus. Ancylometes spiders exhibit unique features like:

  • Powerful front legs for grasping prey
  • Impressive underwater hunting skills

Below is a comparison table of Dolomedes and Ancylometes:

Feature Dolomedes Ancylometes
Family Pisauridae Ctenidae
Diet Fish, insects, and aquatic creatures Fish, aquatic creatures
Size Large (similar to wolf spiders) Large
Localization Mostly in North America South and Central America
Water Near water and aquatic habitats Near water and in water

As you learn about Dolomedes and Ancylometes, you’ll discover fascinating information about these incredible fish-eating spider species. Embrace your curiosity and delve into the world of these amazing arachnids!

Spider Adaptations for a Fish Diet

Adaptive Hunting

Fishing spiders have developed unique hunting techniques to catch small fish. They mainly inhabit areas near water, like ponds, wetlands, swamps, rivers, and lakes. These spiders are widespread across the continents with diverse habitats. They wait patiently near the water’s edge until they sense vibrations signaling potential prey. Some fishing spider species can even swim and dive to pursue their prey underwater.

Using their front legs, they grab hold of their aquatic prey and pull it out of the water. They have been observed catching fish larger than themselves. Their hunting prowess allows them to thrive in various body of waters like rivers, lakes, and swamps.

Physical Modifications

Fishing spiders have developed several physical adaptations to facilitate their specialized diet. Here are some of their important features:

  • Size: These spiders are usually larger than other spider species, giving them the strength to catch and handle fish.
  • Legs: Their legs are equipped with specialized hairs that allow them to walk on water and maintain balance while hunting.
  • Swimming abilities: Some fishing spider species can swim and even dive underwater to catch their prey.

Fishing spiders are related to the larger wolf spiders in size, shape, and coloration. However, their unique hunting skills and physical adaptations make them distinct from their terrestrial counterparts. The fishing spider’s success can be attributed to their ability to catch prey both in and around the water, making them a fascinating subject of study.

Scientific Studies and Research

You may wonder about the scientific research behind spiders that eat fish. Well, researchers Martin Nyffeler from the University of Basel and Bradley Pusey from the University of Western Australia conducted a study on this topic. Their findings were published in a reputable scientific journal called PLOS ONE.

Their research provided evidence that fish predation by semi-aquatic spiders is geographically widespread, occurring on all continents except Antarctica. Interestingly, it appears to be more common in warmer areas between 40° S and 40° N. Some features of fish predation by spiders include:

  • Fish typically range from 2-6 cm in length
  • Captured fish are among the most common fish taxa

A key takeaway from their work is that fish-eating spiders are a fascinating part of nature. They serve as examples of the incredible adaptability and diversity found within the world of arachnids. So, whenever you encounter fishing spiders near water bodies, remember the amazing facts and research you’ve learned here today.

Spiders, Fish, and the Environment

Fishing spiders are large spiders often found near water and are known to catch small fish and aquatic insects. They typically live in freshwater environments, such as ponds, lakes, rivers, and wetlands.

You might have seen these spiders walking on the surface of the water near ponds or wetlands in areas like South America or the wetlands of Florida. Interestingly, some fishing spiders are able to run across the water’s surface to catch their prey and avoid predators.

Fishing spiders contribute to the balance of nature in these environments. They help control the populations of insects and small fish, which in turn keeps the food chain balanced and fosters biodiversity in aquatic ecosystems. In freshwater streams and wetlands, for example, the presence of fishing spiders helps maintain the health of the ecosystem.

While fishing spiders are often associated with wetlands and other aquatic environments, they are also found in terrestrial habitats. In comparison to their aquatic counterparts, terrestrial fishing spiders typically hunt insects and other arthropods rather than fish.

Here are some key features of fishing spiders:

  • Large size
  • Found near water
  • Catch small fish and insects
  • Contribute to the balance of aquatic ecosystems
  • Can walk on the water’s surface

In conclusion, fishing spiders play a crucial role in maintaining the ecological balance in freshwater environments. So, next time you find yourself near a pond, lake, river, or wetland, keep an eye out for these fascinating creatures and appreciate the important part they play in our ecosystems.

Fish Spiders in Popular Culture

You might have come across mentions of fish spiders in various forms of media. These fascinating creatures have piqued the interest of many due to their unique ability to catch small fish and aquatic insects. In this section, we’ll take a brief look at how fish spiders have appeared in popular culture.

Fishing spiders belong to the genus Dolomedes and are known for their large size and presence around water bodies. Their fascinating hunting methods have been featured in documentaries showcasing the wonders of nature. TV shows like BBC’s “The Hunt” and National Geographic’s “World’s Weirdest Animals” have highlighted the prowess of these spiders in catching their prey.

In literature, some authors use fish spiders as a symbol of resilience and adaptability. These spiders are often portrayed as characters that possess the unique ability to live both on land and water, opening up opportunities for exciting plot points and intricate world-building.

In the world of merchandising and art, fish spiders have also made their mark. Enthusiasts of these creatures can find various items adorned with fish spider imagery, ranging from T-shirts to art prints. Additionally, they can be found as subjects of photography or as inspiration for tattoo designs.

A few examples of how fish spiders are incorporated in popular culture:

  • Documentary features such as BBC’s “The Hunt”
  • Nature-based television shows like National Geographic’s “World’s Weirdest Animals”
  • Symbolic representation of resilience and adaptability in literature
  • Custom-made merchandise and artwork inspired by these fascinating creatures

As you explore the world of fish spiders in popular culture, you’ll discover their unique characteristics and behaviors that continue to captivate audiences and spark creativity.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Fishing Spider with Egg Sac and Spiderlings, and Funnel Web Spider


nursery web spider vs. funnel web spider
You recently identified a large spider carrying a big egg sack to a funnel nest as a nursery web. I think it is a funnel web…because of the striped legs…and the funnel in a tree location..somewhere around Durham NC. I believe that the nursery web spiders have a drabber appearance…but i just thought you might want to check it out. Tell me if I am wrong because I find these spiders all the time, and I’d love to know exactly what it was. Best,
mary Sonis

Followup: crittercam
This is my funnel web spider…I think…the egg sac she is carrying is the size of a shooter marble. her eggs hatched…that’s a lot of spiderlings she was near her mate in this funnel…note the striped legs on both … so what do you think it is? I’m not convinced this girl is a fishing spider By the way , I love your site! Best,
Mary Sonis

Hi Mary,
We were having some trouble making sense out of your multiple letters and referred back to the posting on our site that you cited from September 18, 2005 which is on our Spiders 5 page. Terry wrote: “Both were originally just outside the hole in a hollow tree” but he makes no mention of a web. Your letter included three of your own photos, two of the female with egg sac and hatchlings, and another photo. You wrote “she was near her mate in this funnel.” We are identifying your female spider with the egg sac and her hatchlings as a Dolomedes Fishing Spider, one of the Nursery Web Spiders. You can look at the photos posted to BugGuide and see that many have the striped legs you are using to identify Funnel Web Spiders. You can also see from the images on BugGuide, that Funnel Web Spiders in the family Agelenidae also have striped legs. They are not as big as the Dolomedes Fishing Spiders, and they spin funnel webs, unlike the hunting Dolomedes that don’t spin webs. Your mistake is in thinking that you have photos of one species when you have actually photographed two species. We are most thrilled with your photo of the female Dolomedes with her hatchlings.

Dear Daniel,
Thank you for all the help with this. Ok, I have 2 species..I am curious why my Dolomedes would build her nursery web 6 inches from a funnel spider…and actually within the webbing of the funnel. I would think the funnel spider would think she had won the lottery as far as dinner is concerned! As far as I can see the funnel web has eaten none of our spiderlings…who are slowly dispersing along my back wall. i really appreciate all your effort on this…your site is just dynamite. Sincerely,
Mary Sonis

Followup: (08/14/2008)
Hi again Mary,
One more thought for you to ponder is that though many spiders are maternal and protective of their eggs and young, including Fishing Spiders, Wolf Spiders, and Lynx Spiders, we do not know of a single case where the female spider wants anything to do with her mate once she has mated, unless she wants to eat him like a Black Widow. Why the Fishing Spider would choose to deposit her spiderlings near a Funnel Web Spider is a very good question.

Letter 2 – Fishing Spider with Spiderlings


Fishing Spider?
Location:  Ellsworth, Maine
July 24, 2010 9:11 pm
We were vacationing in northern Maine and after a few days, this spider appeared on the dock with an eggsack. The eggsack then hatched and there were probably around 50-100 little spiders running around. A few days later, Mom and her babies had all disappeared. I looked through your website and it looks like a fishing spider, but I just wanted to check. She was rather large – her body was probably two inches long. In the picture you can sort of see all the babies in the web. We never actually saw her go in the water or leave the web.

Fishing Spider with Spiderlings

Hi Nyle,
This photo is wonderful documentation of the maternal behavior of a Fishing Spider in the genus
Dolomedes.  The female begins by carrying her egg sac around in her chelicerae or fangs.  She will then weave her nursery web in a protected location and continue to guard the egg sac and the newly hatched spiderlings until they begin to disperse.  We believe the species is Dolomedes tenebrosus, though we would not rule out Dolomedes scriptus.

Letter 3 – Fishing Spiders and Male Crevice Weavers


Dark Fishing Spiders- Very helpful in the house
June 14, 2011 4:25 am
You might be interested to know that dark fishing spiders absolutely love to hunt and eat brown recluses. I got rid of an infestation using my girl. (girl because she has probably more than 100 babies that I released.) If people knew about her kind eating the dangerous spiders, maybe fewer would be killed! She may be big and intimidating, but she sure helped with that problem before I got bit by a recluse a second time!
My wolf spider hunted them a bit too, but went after crickets more. Now those are spiders to have around the house! Especially because most pesticides don’t effect recluses!
Another thing about spiders-
Recluses like moisture and can climb through pipes. I had several come out of an unused sink drain and one came up through the toilet! Watch out so you don’t get your butt bit.
Signature: Cassie Bryan

Cassie’s Fishing Spider

Dear Cassie,
Thanks so much for your email.  We hope the advice you offer will prevent the Unnecessary Carnage of large and scary, though harmless Fishing Spiders.  We are illustrating your email posting with photos from our archives of a Fishing Spider and a Brown Recluse.




Male Crevice Weever from the archives

Ed. Note: June 23, 2011
Cassie just provided us with another account of raising Fishing Spiders and them feeding on Brown Recluse Spiders.  We were able to replace the Fishing Spider image from our archives with one of Cassie’s own photos.





Letter 4 – Fishing Spider


Subject: Spider identification please
Location: SW WI, USA, bluffs near river
January 4, 2017 2:42 pm
This is a picture I took in Mid fall 2016.
It was taken in SW WISCONSIN USA. Vernon County.
It was found on a house (doorjam leading into house) that is built on the bluffs which surround the banks of the MISSIPPI RIVER.
Please help identify.
Signature: Angela Zitzner Karwoski

Fishing Spider

Dear Angela,
Your Spider is a member of the genus
Dolomedes in the Nursery Web Spider family.  Dolomedes species are commonly called Fishing Spiders or Dock Spiders because they are generally found near bodies of water, and though fish do not constitute their primary source of food, Fishing Spiders are capable of walking on the surface of water and then diving below the surface for protection or to capture aquatic prey, including small fish.

Letter 5 – Fishing Spider


Subject:  cave spider
Geographic location of the bug:  west tennessee usa
Date: 09/12/2017
Time: 10:21 AM EDT
A gew friends and i went hiking and found a cave. We went inside and found some big spiders! I took some video of it and svreen shot a spider. Searched google for the spider and could not find. So i figured i would try to submit it and maybe find out what kind it is.
How you want your letter signed:  Tony Hill

Fishing Spider

Dear Tony,
Was the cave near a stream or other body of water?  This is a Fishing Spider in the genus

Yes it was! Fishing spider eh? Thank you so much. Was really hoping to find a new species, but its ok. Thank you so much for your help!

Letter 6 – Fishing Spider


Subject:  What kind of spider?
Geographic location of the bug:  Rhode Island -Kingston
Date: 06/14/2018
Time: 04:40 PM EDT
Your letter to the bugman:  I think this is a Carolina Wolf Spider or maybe a fishing spider but not sure.  She is a beauty though
How you want your letter signed:  Cynthia Holt

Fishing Spider

Dear Cynthia,
This impressive spider is one of the Fishing Spiders in the genus
Dolomedes, most likely Dolomedes tenebrosus which you can read about on BugGuide.

Letter 7 – Fishing Spider


Subject:  Huge spider
Geographic location of the bug:  Canonsburg pa
Date: 07/09/2018
Time: 03:36 AM EDT
Your letter to the bugman:  I keep finding these and others similar. They are tearing up the woods behind my home for a new complex.
How you want your letter signed:  Thanks

Fishing Spider

This is a Fishing Spider in the genus Dolomedes, and they are not considered dangerous.  We are always sad to hear about habitat destruction in the name of progress.

Letter 8 – Fishing Spider with Egg Sac


Subject:  some type of wolf spider
Geographic location of the bug:  arvada,co
Date: 07/10/2018
Time: 11:32 PM EDT
Your letter to the bugman:  i found this at a creek in arvada.i believe it is some type of wolf spider but id lile a more detailed identification. you might notice the egg sac shes holding in her fangs, she laid it ahout a week after i found her. ive had her for around three weeks.
How you want your letter signed:  Alex

Female Fishing Spider with Egg Sac

Dear Alex,
This is a Fishing Spider in the genus
Dolomedes, not a Wolf Spider.  Both Fishing Spiders and Wolf Spiders have well documented maternal behavior, and both transport an egg sac after producing it.  The Wolf Spiders drag the egg sac from the spinnerets, and when the spiderlings hatch, they crawl on the body of the female for several days before eventually dispersing.  Fishing Spiders carry the egg sac in the chelicerae or fangs as your image illustrates, and like other Nursery Web Spiders, they will eventually construct a nursery web that they guard when they find a location that is appropriate.  Dolomedes scriptus is reported from Colorado according to BugGuide, and the individual in this BugGuide image has markings very much like your Spider, so we believe that species is correct.   Fishing Spiders are often found near water, and adult Fishing Spiders are capable of capturing aquatic prey, including small fish.

Fishing Spider

thank you SO much! this was very helpful and I am very impressed in how quickly you got back to me. have a wonderful day!

Fishing Spider


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

    View all posts
  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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