Are Fishing Spiders Poisonous? Debunking Common Myths

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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.

 

Are Fishing Spiders Poisonous
White-Banded Fishing Spider

Fishing Spiders Overview

Dolomedes Species

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.

Distribution Differences:

  • North America (USA and Canada): Dark fishing spider, Dolomedes tenebrosus
  • Europe: Dolomedes fimbriatus
  • Asia: Dolomedes raptor
  • Africa: Dolomedes orion

Pisauridae Family

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.

 

Fishing Spider we believe

 

Comparison Table

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.

Hydrophobic Abilities

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.

Hunting Behavior

  • 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.

Quick Facts:

  • 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:

  • Ponds
  • Streams
  • Swamps

These environments support a variety of trees and vegetation that fishing spiders use as shelter.

 

Fishing Spider

Typical Prey and Predators

Fishing spiders mainly eat small fish and aquatic insects. Their hunting method includes catching their prey from the water’s surface.

Some of their typical prey include:

  • Small fish
  • Aquatic insects
  • Tadpoles

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

Comparison table:

Environment Description Example
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.

The effects of a fishing spider bite on humans are considerably less severe than bites from more dangerous spiders, like the brown recluse or black widow.

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:

  1. Clean the wound with soap and water
  2. Apply ice to reduce swelling
  3. 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:

  • Insects
  • 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:

  • Birds
  • Wolves
  • 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.

Global Distribution

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

Dock Spider

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

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

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.

Comparison Table

Spider Type Hunting Technique Lifespan Dangerous to Humans
Dock Spider Walking on water Short No
Wharf Spider Stealth 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.

Conclusion

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.

Footnotes

  1. Spiders | UMN Extension 2 3

  2. Fishing Spider – Penn State Extension 2

  3. Fishing spiders – MSU Extension

  4. Fishing Spiders of Europe – Eurospiders

  5. Asian Dolomedes Species – Asian Arachnids

  6. African Dolomedes Species – African Spider Database

  7. Fishing Spiders and Wolf Spiders – NC State Extension Publications

  8. Spiders | UMN Extension

  9. Fishing spiders – MSU Extension

 

Fishing Spider

Fishing Spider

Fishing Spider


Authors

  • 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.

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  • 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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Tags: Fishing Spider

Related Posts

11 Comments. Leave new

  • Dolomedes indeed!

    Reply
  • Hi there,
    Saw this one in my sister’s back yard in Lancaster County, PA. I think it might be a Fishing Spider, but it seems to have lighter coloration than most pictures that I’ve seen.
    https://fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-ash4/200171_10200389279553017_7717627_n.jpg

    Reply
  • Frank Kurczewski
    July 18, 2014 12:13 pm

    Why not Dolomedes albineus, an grayish colored argboreal species?

    Reply
  • Just took a pic tonight of a giant fishing spider at Marsh Creek lake. Awesome!

    Reply
  • I live in Franklin, TN. I was fishing on the Harpeth river casting across and noticed a huge (relative to what I normally see) spider on a tree trunk growing out of the water. It was only a few inches from the water and I noticed it as it moved when my lure (a floating jig) hit the water about a foot from where it was perched. It was brownish-gray and seemed to match the tree bark closely. It had a round, flat abdomen about the size of a silver dollar. Total length was about 2.5 – 3.5 inches. I assume it is either a Huntsman or Fishing spider?

    Reply
  • Thank you. I appreciate it. How big can they get when fully mature?

    Reply
  • Gladys V-Riojas
    January 21, 2017 10:05 pm

    We took a pic of one fishing spider. My kids were freaking out of course seeing spiders would scare anyone especially me! But we did the research when we got home. Thanks for the info! San Antonio Tx
    Crescent Nature Park in Schertz

    Reply
  • Gladys V-Riojas
    January 21, 2017 10:05 pm

    We took a pic of one fishing spider. My kids were freaking out of course seeing spiders would scare anyone especially me! But we did the research when we got home. Thanks for the info! San Antonio Tx
    Crescent Nature Park in Schertz

    Reply

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