Fishing spiders, from the genus Dolomedes, are known for their impressive size and unique hunting methods.
They can be found near water sources, such as streams or ponds, where they lie in ambush for their prey.
Interestingly, fishing spiders can also “skate” across water surfaces and dive under to capture their prey, which includes small fish and aquatic insects.
While these spiders may seem intimidating due to their size and hunting techniques, their venom is not medically significant to humans.
This means that even if a fishing spider were to bite a person, the effects would likely be mild, such as localized pain and swelling.
However, it’s important to note that fishing spiders are generally non-aggressive and rarely bite unless provoked.
Fishing Spiders Overview
Fishing spiders belong to the Dolomedes genus, which comprises several different species.
These spiders are known for their remarkable ability to “skate” across water surfaces and dive underneath to catch prey, such as small fish and aquatic insects1.
They can be found in various parts of the world, including North America, Europe, Asia, Africa, South America, and New Zealand2.
- North America (USA and Canada): Dark fishing spider, Dolomedes tenebrosus
- Europe: Dolomedes fimbriatus
- Asia: Dolomedes raptor
- Africa: Dolomedes orion
Fishing spiders are part of the Pisauridae family, which also includes other large, terrestrial spiders like wolf spiders7. Members of this family share some common characteristics:
- Size: Large body size (around 1 inch long, sometimes larger). Females are larger in size.
- Appearance: Brown or grayish color, with white markings8
- Habitat: Usually associated with water sources, such as rivers, lakes, and ponds
For example, the dark fishing spider (Dolomedes tenebrosus) found in the USA and Canada is considered one of the largest spiders, reaching over an inch in length (not including legs) and having a leg span of up to 3 inches.
|Feature||Dolomedes Species||Pisauridae Family|
|Size||Large (around 1-inch)||Large (around 1-inch)|
|Appearance||Brown/gray, white markings||Brown/gray, white markings|
|Habitat||Near water sources||Terrestrial|
Physical Characteristics and Behavior
Size and Color
Fishing spiders are quite large, with some species having a body length of about 1 inch.
Their coloration typically ranges from brown to black, helping them blend in with their surroundings.
For example, the dark fishing spider (Dolomedes tenebrosus) has a black and brown pattern on its abdomen.
Legs and Eyes
These spiders possess eight legs, which are long and strong. Their legs allow them to move quickly and efficiently on the water’s surface.
Fishing spiders also have eight eyes, arranged in two rows on the front part of their cephalothorax.
Their good vision helps them locate prey and avoid predators.
Fishing spiders have hydrophobic hairs on their legs, which repel water and enable them to walk on water surfaces.
This characteristic feature allows them to hunt for their aquatic prey more effectively.
- Fishing spiders are ambush predators
- They wait for prey near water surfaces
- They can catch small fish and aquatic insects
Fishing spiders’ hunting strategy usually involves waiting patiently near the water’s surface, where they can detect the vibrations and movements of their prey.
Once they locate their target, they quickly strike to capture it.
- Not aggressive toward humans
- They are not venomous to people, but they can bite if threatened
- Bite symptoms usually include localized pain and swelling
Habitat and Diet
Aquatic and Semi-Aquatic Environments
These spiders are adapted for life on and around water. They can be found in relatively calm and undisturbed places like:
These environments support a variety of trees and vegetation that fishing spiders use as shelter.
Typical Prey and Predators
Some of their typical prey include:
- Small fish
- Aquatic insects
Occasionally, they also hunt other insects and small invertebrates found in their habitat. Fishing spiders are themselves preyed upon by larger predators like birds, amphibians, and bigger spiders.
Key features of the fishing spider’s diet:
- Mainly aquatic based
- Hunting on water surfaces
- Variety of prey that includes small fish and insects
Characteristics of their habitat:
- Calm and undisturbed places
- Presence of water bodies
- Availability of trees and vegetation for shelter
|Aquatic||Found near water bodies||Ponds, streams|
|Semi-Aquatic||Found in areas with a mix of water and land||Swamps, marshes|
Are Fishing Spiders Poisonous or Venomous?
Poisonous or Venomous?
- Poisonous: Causing harm when ingested, inhaled, or touched
- Venomous: Causing harm through injection of venom, such as through a bite or sting
Fishing spiders, specifically the Dolomedes tenebrosus, are venomous, as they inject venom through their bites.
However, their venom is not significantly dangerous to humans1.
Effects on Humans
Fishing spider bites are rare, as these spiders typically only bite when threatened.
Comparing Spider Bites:
|Spider||Bite Severity||Common Symptoms|
|Fishing Spider||Mild||Mild pain, redness|
|Brown Recluse||Moderate||Ulcers, tissue damage|
|Black Widow||Severe||Muscle cramps, nausea|
Symptoms and Treatments
Symptoms of a fishing spider bite may include:
- Mild pain or discomfort
- Minor redness and swelling around the bite site
If bitten, you should:
- Clean the wound with soap and water
- Apply ice to reduce swelling
- Seek medical attention if symptoms don’t improve within a few days1
Overall, while fishing spiders are venomous, their bites are rarely dangerous to humans. The symptoms associated with their bites are generally mild and easily treatable.
Life Cycle and Reproduction
Mating and Egg Laying
Fishing spiders belong to the Pisauridae family and have a unique mating and egg-laying process. Males initiate mating by offering a gift, such as a wrapped prey item, to the females.
This helps in preventing them from becoming the females’ next meal. Females then produce egg sacs.
- Females: Larger and more dominant than males
- Males: Smaller and offer gifts to initiate mating
Examples of gifts males may offer:
- Other small prey
Nursery Web and Spiderlings
After egg-laying, females create a nursery web to protect their eggs and newly hatched spiderlings. These webs serve as temporary homes for the young until they are ready to venture out independently.
Benefits of nursery webs:
- Protection from predators like birds and wolves
- Ensures optimal conditions for growth
Possible predators of fishing spiders:
- Larger spiders
Upon hatching, spiderlings are ready to begin their lives, using their instincts to hunt, avoid predators, and ultimately reproduce.
Comparison of fishing spider life stages:
|Life Stage||Main Characteristics|
|Egg sac||Containing eggs, protected by the mother|
|Spiderlings||Hatch from egg sacs; reside in nursery web|
|Juveniles||Grow and molt through various stages|
|Adults||Males offer gifts to females for mating; short lifespan|
Prevalence and Identification
North American Species
Fishing spiders are commonly found across North America, including the USA, Canada, and even in states like Florida and Texas. They can be spotted near water sources, especially during spring.
Identifying fishing spiders can be simple if you know their key features:
- Alternating brown/black bands on legs
- Long legs relative to body size
- Often found near water
For example, the Dock spider (Dolomedes species), also known as the Fishing spider, is prevalent in North America.
Fishing spiders have a wide global distribution, including continents like Asia, Africa, Europe, South America, and even countries like New Zealand. Here is a comparison of fishing spiders in different regions:
|Region||Fishing Spider Features|
|North America||Long legs, brown/black bands|
|Asia||Similar to North American species|
|Europe||Varying sizes and color patterns|
|South America||Diverse habitats, leg patterns|
Additional Interesting Facts
The dock spider, also known as the fishing spider, is found near water bodies and is known for its unique hunting tactics. Although they are not venomous to humans, their bite might cause mild irritation.
- Lifespan: Dock spiders have a relatively short life span.
- Wily Hunters: They use their agility to catch small fish and aquatic insects by walking on the water’s surface.
Wharf spiders are another type of fishing spider that thrives near docks and piers. They are predators of small aquatic animals as well as insects.
- Deceitful: Wharf spiders are known to be deceitful in their hunting approach, using stealth to capture their prey.
- Not Harmful to Humans: Like dock spiders, they are not venomous to humans, but a bite can still be uncomfortable.
Raft spiders are semi-aquatic species of fishing spiders that live near freshwater bodies. They have similar habits to the dock and wharf spiders.
- Special Adaptation: Raft spiders can “skate” on the water surface thanks to the hydrophobic hairs on their legs.
- Fishing Technique: They use their legs to detect vibrations in the water, helping them locate and capture prey.
|Spider Type||Hunting Technique||Lifespan||Dangerous to Humans|
|Dock Spider||Walking on water||Short||No|
|Raft Spider||Skating on water||Short||No|
Overall, these fishing spiders, while wily and deceitful in their hunting techniques, are not venomous or harmful to humans. Their unique adaptations and hunting methods make them fascinating creatures in the world of spiders.
In conclusion, Fishing spiders are known for their size, hunting prowess, and unique behaviors.
Their appearance and ability to “skate” on water and capture aquatic prey, may sound scary but they are not harmful to humans.
Yes, they are venomous in nature, however, the venom is generally mild and rarely poses a serious threat to our well-being.
However, understanding more about these creatures can help us to stay safe from them and to minimize injuries.
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about fishing spiders. Scroll down to have a look at some of them.
Letter 1 – Fishing Spider
Wolf or Fishing Spider?
Location: Southeastern, Ontario
September 18, 2011 6:58 am
Dear Bugman, I keep finding these large spiders around my backyard, usually around the pool or the deck. This one was around the patio doors. I would just like to have it identified and find out if they would harm a child if bitten.
This is most assuredly a Fishing Spider in the genus Dolomedes, and in our opinion, it is Dolomedes tenebrosus based on information posted to BugGuide.
According to the information that is available, this is a harmless species, though we would not discount the possibility that one of these shy and docile Fishing Spiders might be provoked into biting a person.
Letter 2 – Fishing Spider
Giant Spider in the bathroom
Location: Weymouth Massachusetts
May 24, 2011 2:45 pm
Dear Bugman, Last night I found this spider in my bathroom. We live in Weymouth Massachusetts and our backyard is all forest.
I have young children and want to ensure that they are safe. Please advise. Thank you!!
Signature: Concerned Mom
Dear Concerned Mom,
Fishing Spiders in the genus Dolomedes are large and though they may appear to be quite frightening, they are harmless.
Letter 3 – Fishing Spider
I found this guy on the wall of my bike shed. We found the same sort of spider, only even bigger, on the floor in our basement a few months ago. They don’t seem to be associated with webs, and they don’t seem to be great climbers. They’re clearly more comfortable on the ground.
And they’re INCREDIBLY fast. This — with the two sets of front legs together — seems to be a common resting position.
This one was 2.5-3″ from leg tip to leg tip. (The one in the basement was 3.5-4″) We live in Saint Paul, MN. We’ve been in our house for years, and we’ve never seen them before. What ARE these guys?
Thanks for your help.
Beautiful photo of a Fishing Spider, genus Dolomedes, probably Dolomedes tenebrosus. It is found in wooded areas, often near water but it can also stray far from ponds and streams.
If disturbed, it can dive below the surface of the water and remain submerged for 30 minutes or longer. It can catch small fish, hence the common name. Though fearsome appearing, they are harmless.
Letter 4 – Fishing Spider
Could you please identify this for me?
I found this spider in my bathroom. I live in North Bay, Ontario, Canada in a mixed deciduous forest, predominately Maple trees. My house is located near but not on a lake. If you could identify it for me I would greatly appreciate it.
I guess your Fishing Spider, Dolomedes species, found itself too far from the lake and decided to try fishing in the bathroom.
Letter 5 – Fishing Spider
Fishing Spiders…nowhere near fish or water?
Hello Lisa and Daniel,
I’ll start by saying that you run a wonderful site, because although I know you get a lot of complimentory emails, you deserve many, many more.
I’ve always loved bugs, mostly because my dad loved them, and I remember whole afternoons spent hunting for them with him, with the wonders and discoveries that I thought only a child could experience when seeing some strange multi-legged thing for the first time.
Your site has proved me wrong, however, as I find myself browsing your images and explanations for whole afternoons…and loving every minute of it.
What a wealth of information! I’m here every time I find a bug I’ve never seen, and then I stay even after identifying it because I know there are many more I haven’t seen in here. So first, KUDOS!
Now second. I’ve attached two pictures of what I believe to be ‘fishing spiders’, or at least spiders of the Dolomedes genus. We get these every year, and when I say these, I mean spiders galore, in the basement.
And they are BIG! They don’t really bother me, I think they’re pretty cool actually, but I’m wondering about one thing: I live in Québec, Canada, and nowhere near water.
I’m in the city and although there are woods behind the house, there is no pond, or stagnant water pool, or anything. Yet every year, they ‘appear’, full grown – I’ve never even seen spiderlings.
One day there’s nothing, and the next, they’re everywhere. They don’t travel upstairs, but I find them more often than not in the litter box. Well camouflaged, too, I don’t see them until I scoop them up.
So I guess my question is: are they really fishing spiders? Or are they something else? And if they are, what are they eating in my basement? And how do they get there?? The ones in the pictures are about the size of a credit card, but we’ve gotten bigger ones.
I tend to release them in the wilderness because although their venom might not be very strong, I have four cats and would not want spiders as part of their diet. My husband thinks they come up through the drain…Is that even possible?
Anyway, I know you’re pretty busy with a lot of emails, and you might not get to answer me quickly – or at all, but I thought you might like the pictures for the site – although you have a lot of them already.
In any case, thanks for all the great work, it really is appreciated!
Your kind letter just made our day. This is a Dolomedes species, the genus of spiders commonly called Fishing Spiders. Not all species, nor even all individuals are found near water. Dolomedes albineus is arboreal. T
he nearby woods are probably responsible for your spider population. At any rate, basements and cellars are generally damp dark places, and that is an ideal habitat for many spiders.
They might be eating one another and they are probably doing a very good job of keeping your home free of other less desirable visitors. We suspect this is Dolomedes tenebrosus, which according to Wikipedia, exhibits female giganticism.
Letter 6 – Fishing Spider
LARGE HUNTING SPIDER: Say Hello to my Little Friend
This girl showed upon my kitchen wall yesterday afternoon, here in Mooresville, NC. She gave me quite a fright. I am 99.9% sure she is a Dark Dolomedes or Dolomedes tenebrosus.
I literally hyperventilated removing her from the wall. But by this afternoon when we released her she had grown on me. I hope she will be ok by the termite and beetle filled log we released her onto.
Most of the info I have found on them, has them much nearer a water source than we are, as well as farther north. Thanks for your time,
This is most definitely a Dolomedes Fishing Spider. Glad to hear it was relocated outdoors.
Letter 7 – Fishing Spider
Possible fisher spider in odd location
Sat, Jun 20, 2009, at 8:16 PM
My friend sent me these pictures of a spider. We think it’s a fisher spider but we’d like confirmation since it was found in a rather atypical location — namely, on her stove in her kitchen!
She lives in southern New York State. It’s mid-June, warm, but not overly hot. There are no bodies of water really close to her home (although there’s a creek down the street).
The spider was non-agressive so she put it on a paper plate and took some photos of it. She took it in a container to work and someone identified it as “a really big spider”.
Obviously, the spider is nearly 2 1/2″ inches (legs included).
She took it to the woods near her home and released it into the wild where she got more fabulous photos of it.
Could you please confirm if it is indeed a fisher spider?
Thanks so much!
Southern New York State
Your identification of a Fishing Spider, Dolomedes tenebrosus, is correct. Fishing Spiders do not build snare webs, and they are a wandering mobile species. Perhaps your friend’s stove was just a warm stop on the way to a new hunting ground. We love the photo on the paper plate.
Letter 8 – Fishing Spider
Monstrous brown spotted spider
June 13, 2009
We were shocked to discover this spider in a forest preserve outside Chicago. The picture actually underestimates its size because the hand shown is in front of the spider. Spider leg span was 3-3.5 inches, and total body size was about two inches. Spider had some fur but wasn’t as hairy as say a tarantula. The hand is small-average male hand.
Lou and Bethany
Just outside of Chicago
Dear Lou and Bethany,
What a wonderful image of a Fishing Spider, probably Dolomedes tenebrosus. Fishing Spiders generally live near water and they have been known to dive beneath the surface and remain there to escape enemies and to fish for prey. They can actually catch fish underwater.
Letter 9 – Fishing Spider
Huntsman Spider or Fishing Spider?
August 26, 2009
Hello. I live in Charleston, SC, and noticed this spider crawling up the side of the house. Biggest spider that I have ever seen around here, hands down. At first, I thought it was a wolf spider, then thought it might be a Fishing Spider.
Now wonder if its not a Huntsman Spider. Can you tell me for sure what it is? And is it aggressive? Poisonous? Thanks in advance.
Your spider is a Fishing Spider in the genus Dolomedes, most likely Dolomedes tenebrosus. You may compare your photo to the ones posted on BugGuide.
Letter 10 – Fishing Spider
What kind of spider is this hideous, and horrifying thing…
June 3, 2010
I work at an animal shelter in SW Michigan. Its the beginning of summer, and we came across a VERY large and dead one of these about 3 weeks ago.
SInce then, an officer has spotted another one in our garage in the same area we found the dead one, and then we found this bugger also in the same location within this last week.
Most of our employees, myself included, are terrified of spiders. I would truthfully rather be face to face with a vicious dog than face one of these bad boys. We are all wondering what kind it is.
We first thought it was a Wolf Spider, but a friend suggested your website and said it could be a Huntsman.
Thank You! Julie Barber
Kalamazoo, MI – Kalamazoo County Animal Services
We believe your spider is a harmless Fishing Spider.
Harmless you say? Perhaps I will continue to go to work afterall…
Thanks! Our staff will be quite relieved!
Letter 11 – Fishing Spider
What kind of spider is this?
June 11, 2010
In southern Wisconsin, June, near a wooded area. This spider is hanging out on my grill cover and creating long strings to the house, (3 feet or so). Seems to be not afraid of me. Is about 2 inches overall tip to tip when standing normally. Hope you can help! Thanks!!
We believe this is Dolomedes tenebrosus, one of the Fishing Spiders. You can compare your images to ones posted to BugGuide.
Letter 12 – Fishing Spider
What’s This Creature?
Location: Hot & Humid Columbia, SC
July 19, 2011 10:05 am
I found this creature (at least 7”) on the side of my house (no web), outside my front door last week. After a short storm, this creature was gone. We’ve been trying to figure out what this is and haven’t had any luck. Thank you.
This is a Fishing Spider in the genus Dolomedes.
Letter 13 – Fishing Spider
AAARGGHH! We hope there aren’t more of them under the dock.
Location: Southeast Wisconsin, Lac La Belle Oconomowoc
August 17, 2011, 9:35 pm
This REALLY big scary-looking spider is the first of its kind ever noticed at this location – on the dock at Lac La Belle in Oconomowoc, WI. It waited all day near what we think is its web, seen in one photo with a finger pointing at. egg sack vs. dinner?
We lake people are used to daddy-long-legs and other spider varieties and bugs of all kinds, but this specimen seems awfully exotic. Any ideas?
Signature: Delahunt Clan
Dear Delahunt Clan,
This magnificent specimen is a female Fishing Spider in the genus Dolomedes. Many species are found near water and some species actively hunt aquatic prey, diving beneath the surface of the water, remaining under for extended periods of time and catching small fish or tadpoles.
Fishing Spiders are hunting spiders that do not build a web to snare prey, however, they are in the Nursery Web Spider family, and they build a web in a suitable location after carrying around the egg sack in their chelicerae or fangs.
When she finds a suitable location for her Nursery Web, the female spider will guard the eggs. Thanks for sending us this wonderful documentation. Fishing Spiders are not considered to be dangerous to humans, though we concede that they might bite, though we have never received a report of a person being bitten by a Fishing Spider.
Thanks so much for your prompt reply!
Our family has had a good time with this new adventure.
And as magnificent as this “specimen” truly is, we really really hope there aren’t more of them under the dock.
But now we know there probably are. : )
Fishing Spiders are also known as Dock Spiders as indicated in this University of Minnesota Extension website posting.
Letter 14 – Fishing Spider
Giant River Spiders
Location: Downingtown, Pennsylvania
September 3, 2011 9:23 am
A friend and I went hiking and wanted to rest and sit on some big stones in the middle of the river. I saw these two long twigs resting on the rock and bent to move them, only to see that those long ”twigs” were legs belonging to a spider the size of my face.
I’ve lived in PA all my life, but I have never seen a spider this big – and it wasn’t the only one. We saw a couple more in the same area. All I know is that they blended really well against the surface, there were only one or two spiders on each rock, and I didn’t see any spiders webs.
I’d like to know if they are poisonous and if they are particularly aggressive. Either way, I’m arachnophobic so I won’t be trekking through creeks and rivers again any time soon.
Signature: ”Why spider god, why?”
We absolutely love your letter and we hope we can dispel your fears. This is a Fishing Spider in the genus Dolomedes, and though we wish your photo had more detail, there is no shortage on our site of excellent images of Fishing Spiders.
Fishing Spiders are large spiders that are often associated with aquatic habitats. They are capable of walking on the surface of the water and even diving beneath the water to escape predators or to capture prey, occasionally small fish, tadpoles and other aquatic creatures.
Like most spiders, they have venom, but they are not considered a species that is harmful to humans. Here is what the Penn State University Entomology website has to say about Fishing Spiders:
“Although a large spider such as D. tenebrosus is able to bite humans, it is a shy spider that will run from people. Bites are typically no more severe than a bee or wasp sting. Exceptions do occur for individuals who are sensitive to spider venoms.”
We have never received a report from anyone that they were bitten by a Fishing Spider.
These are magnificent creatures and we hope you are able to overcome your fears so that you are able to continue to enjoy the wonders of nature in Pennsylvania’s amazing streams, creeks, and other bodies of water.
Letter 15 – Fishing Spider
Location: NE Ohio
May 5, 2012, 9:58 am
Based on other photos on the site, I’m thinking this is a fisher spider. We caught her in the basement and liberated her out by our little pond. She’s a beauty!
We agree that this is a Fishing Spider in the genus Dolomedes. These are large spiders and many people are frightened by their fierce appearance, but we have never received a report of anyone being bitten by a Fishing Spider and they are not considered to be dangerous.
We are tagging your email with our Bug Humanitarian Award thanks to your decision to catch and release rather than stomp or swat. We hope your letter will help to increase our readership’s awareness of the beneficial species that often fall prey to irrational human fears.
Letter 16 – Fishing Spider
Subject: Possible Fishing spider? Please help!
Location: Rome, Maine
May 24, 2012 7:20 am
Dear Bugman, We found this large furry spider hiding under a pillow on our outdoor bench. He has rather long banded legs that seem to have white on them underneath, but he is mostly black and brown. He is about 2 1/2 inches leg to leg and really fast.
Signature: A bug-loving family, in the woods of Maine
Dear bug loving family,
This is indeed a Fishing Spider and we believe it is most likely Dolomedes tenebrosus which you will find described on BugGuide.