dark fishing spider

(Dolomedes tenebrosus)

Conservation Status
dark fishing spider
Photo by Brian Johnson
  IUCN Red List

not listed

     
  NatureServe

NNR - Unranked

     
  Minnesota

not listed

     
           
           
           
           
           
           
           
 
Description
 
 

Dark fishing spider is a large, robust, nursery web spider. It is the largest fishing spider, the second largest spider in North America, and the largest spider in Minnesota.

The adult female body is to 1 long. It is light brown with light and dark brownish-gray markings.

The front part of the body (cephalothorax) is about the same size as the rear part (abdomen). The covering (carapace) of the cephalothorax has dark markings that resemble the face of an ant. On the front on the cephalothorax there are eight eyes in two rows of four each. Both rows of eyes are moderately curved. The inner eyes in the back row are only slightly larger than the outer eyes.

The abdomen is rounded in the front, widest in the middle, and tapers toward the rear. On the rear half of the abdomen there are three conspicuous, dark, “W” shaped markings, each mark ending in a light brown mark. The “W” marks may be somewhat outlined in white but the outline will be broken and incomplete.

Each leg is conspicuously banded and has long black spines. The femur is light brown with black bands and the tibia are reddish-brown with black bands. The last leg segment (tarsus) has 3 claws. The legs are very long in proportion to the body size. The legspan of the female can be over 3.

The male is similar to the female but only about half the size, ¼ to ½ long, and one-fourteenth the weight.

 
     
 

Size

 
 

Male: ¼ to ½
Female: to 1

 
     
 

Similar Species

 
 

Striped fishing spider (Dolomedes scriptus) is similar but smaller. The “W” markings on the rear of the abdomen are outlined in white all across the abdomen. The legs appear longitudinally striped, not horizontally banded.

Wolf spiders (family Lycosidae) have three rows of eyes, including a pair of very large posterior median eyes. The anterior median eyes are not visible from the front. Wolf spiders are most often seen perched horizontally.

 
     
 
Habitat
 
 

Deciduous forests, often far from water; human houses near deciduous forests.

 
     
 
Biology
 
 

Season

 
 

Early May through September

 
     
 

Behavior

 
 

Dark fishing spider is most often seen perched vertically. It hunts for prey mostly at night, remaining motionless on a tree trunk, wall, or other vertical surface.

 
     
 

Life Cycle

 
 

Dark fishing spider reproduces in mid-summer. A 2013 study shows that the male never survives the mating process. The male is monogamous, not out of loyalty, but because it spontaneously dies after mating while still attached to the female. The female then eats the dead male. In June the female produces a large egg sac into which she begins laying eggs. She carries the egg sac around with her mouth as she wanders about. The egg sac will eventually contain up to almost 1,400 eggs and be up to in diameter. When the eggs are about the hatch she attaches the sac to foliage well above the ground, builds a nursery web around it, and stands guard near it. The newly hatched spiderlings remain in the nursery web until they molt, and then they disperse.

Immature adults hibernate under stones, under loose bark, in tree cavities, and in human dwellings. Males mature and mate in the spring of the first year. Females mature in two years.

 
     
 

Food

 
 

Large insects and small vertebrates

 
     
 
Distribution
 
 

Distribution Map

 

Sources

24, 29, 30.
 
  9/9/2021      
         
 

Occurrence

 
 

Regularly occurring

 
         
 
Taxonomy
 
  Class Arachnida (arachnids)  
 

Order

Araneae (spiders)  
 

Suborder

Araneomorphae (true spiders)  
  Infraorder Entelegynae (eight-eyed spiders)  
 

Superfamily

Lycosoidea (wolf spiders and allies)  
 

Family

Pisauridae (nursery web spiders)  
 

Genus

Dolomedes (fishing spiders)  
       
 

Synonyms

 
 

 

 
       
 

Common Names

 
 

brownish-gray fishing spider

dark fishing spider

 
       

 

 

 

 

 

 

 

Glossary

Carapace

The hard, upper (dorsal), shell-like covering (exoskeleton) of the body or at least the thorax of many arthropods and of turtles and tortoises.

 

Cephalothorax

The front part of a spider’s body, composed of the head region and the thoracic area fused together. Eyes, legs, and antennae are attached to this part.

 

Femur

On insects and arachnids, the third, largest, most robust segment of the leg, coming immediately before the tibia. On humans, the thigh bone.

 

Tarsus

The last two to five subdivisions of an insect’s leg, attached to the tibia; the foot. Plural: tarsi.

 

 
 
Visitor Photos
 
           
 

Share your photo of this arachnid.

 
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Simply email us at info@MinnesotaSeasons.com.
Attach one or more photos and, if you like, a caption.
 
 

Dave Bellmont

 
    dark fishing spider      
 

Mary Gaines

 
 

Dark fishing spider

This was on our screen in St. Louis Park MN yesterday.

I saw other people posting pics on your site so thought I’d share mine.

  dark fishing spider  
 

Twiztedtiff1488

 
 

I found him on my deck one night and was thinking he was huge so I grabbed a cup and captured him to take pictures and then released him

  dark fishing spider  
           
    dark fishing spider   dark fishing spider  
           
    dark fishing spider      
 

KSIvan

 
 

May 28, 2021

 
    dark fishing spider      
 

Beth

 
    dark fishing spider   dark fishing spider  
 

NorthernMNmom

 
    dark fishing spider      
 

Jason Halverson

 
 

found it under the grill cover outside.

 
    dark fishing spider   dark fishing spider  
 

Benjamin Merk

 
  We have a lot of these in our house up in Lindstrom MN. Is it a fishing spider?   dark fishing spider  
 

Jordan Plotz

 
 

Caught in Pelican Rapids MN in Ottertail County

 
    dark fishing spider   dark fishing spider  
           
    dark fishing spider   dark fishing spider  
 

Marie Erickson

 
  It zipped across the kitchen floor! Sucked it up in my Dyson. A friend had one the next day near her foundation. Both at cabins near the lake!   dark fishing spider  
 

Anonymous 3

 
 

Hit my arm, scared me half to death!

 
    dark fishing spider   dark fishing spider  
 

Jamie Miller

 
    dark fishing spider      
 

Steve Marquardt

 
 

on driveway apron, outside of garage.

  dark fishing spider  
 

Annette Pallesen

 
    dark fishing spider   dark fishing spider  
 

Michele Lloyd

 
  On the inside of the screen of our sliding glass door. I am assuming that is her egg sac.   dark fishing spider  
 

Brian Johnson

 
  This spider was in the tall grass. The span of the legs was close to 90 mm. The body close to 30 mm.   dark fishing spider  
           
 
MinnesotaSeasons.com Photos
 
 

 

 
           
           

 

Camera

     
 
Slideshows
 
  Dolomedes tenebrosus (Dark Fishing Spider)
Allen Chartier
 
  Dolomedes tenebrosus (Dark Fishing Spider)  
     

 

slideshow

       
 
Visitor Videos
 
       
 

Share your video of this arachnid.

 
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Other Videos
 
  Video S1
Royal Society journal supplements
 
   
 
About

Published on Jun 19, 2013

Spontaneous male death in the dark fishing spider, Dolomedes tenebrosus. (1) Male is introduced into the mating arena. (2) D. tenebrosus courtship behaviour. (3) Copulation and spontaneous male death. (4) Male is detached from the female and removed from the mating arena. Video by Steven K. Schwartz. This research was published in the journal Biology Letters in the paper: Spontaneous male death and monogyny in the dark fishing spider by Steven K. Schwartz, William E. Wagner Jr and Eileen A. Hebets. The doi link for the article is http://rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2013.0113

 
  Dolomedes Tenebrosus Mating
Silka Buns
 
   
 
About

Uploaded on Jun 3, 2010

I believe it is the hemoglobin pressure that was released which shocked/killed the male. However, I could be wrong. Cheers!

Please enjoy this video of Dolomedes Tenebrosus giving eachother some lovi

 
  Dolomedes Tenebrosus - Brownish Grey Fishing Spider HD
trumansnare
 
   
 
About

Uploaded on Jan 20, 2011

Brownish-Grey Fishing Spider (Dolomedes Tenebrosus)
Feeding video and hand held pictures.
All video and Pictures were shot by me.

Makes for an awesome pet. Much different than holding a tarantula, these may not be AS big. But they are big, and extremely fast. Let this thing run up your arm :)

Video Cam:
Panasonic SD60

Camera D-SLR:
Canon 450D Rebel Xsi

 
  Dark Fishing Spider (Pisauridae: Dolomedes tenebrosus) on Fence
Carl Barrentine
 
   
 
About

Uploaded on Aug 8, 2011

Photographed at the Turtle River State Park, North Dakota (07 August 2011). Thank you to Lynette Schimming (@Bugguide.net) for confirming the identity of this specimen!

 
  The Dark Fishing spider’s Deadly Mating Game - ScienceTake | The New York Times
The New York Times
 
   
 
About

Published on Oct 1, 2013

For male spiders, mating with a larger, hungry female can be a risky business. But for the dark fishing spider, sex is guaranteed death sentence.

Subscribe to the Times Video newsletter for free and get a handpicked selection of the best videos from The New York Times every week: http://bit.ly/timesvideonewsletter

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The Dark Fishing spider’s Deadly Mating Game - ScienceTake
http://www.youtube.com/user/TheNewYorkTimes

 
       

 

Camcorder

 
 
Visitor Sightings
 
           
 

Report a sighting of this arachnid.

 
  This button not working for you?
Simply email us at info@MinnesotaSeasons.com.
Be sure to include a location.
 
  Dave Bellmont
9/7/2021

Location: near Lake Shamineau, Motley, MN, USA

dark fishing spider

 
  Mary Gaines
8/26/2021

Location: St. Louis Park, MN

This was on our screen in St. Louis Park MN yesterday.

I saw other people posting pics on your site so thought I’d share mine.

dark fishing spider

 
  Twiztedtiff1488
7/19/2021

Location: Rochester MN

I found him on my deck one night and was thinking he was huge so I grabbed a cup and captured him to take pictures and then released him

dark fishing spider

 
  Mark Carroll
7/11/2021

Location: BWCAW Tofte Region

Saw one on a lily pad, one of a rock near the water and one swimming in a lake

 
  KSIvan
5/28/2021

Location: Chisholm, MN

May 28, 2021

dark fishing spider

 
  Beth
5/6/2021

Location: Greenwood Lake, Gunflint Trail

dark fishing spider

 
  Mike Saunders
7/1/2020

Location: Caribou Lake (Lutsen)

male and female on the dock

 

 
  NorthernMNmom
6/23/2020

Location: St. Louis County

dark fishing spider

 
  Jason Halverson
6/21/2020

Location: Leech Lake, MN

found it under the grill cover outside.

dark fishing spider

 
  Benjamin Merk
6/10/2020

Location: Lindstrom MN

We have a lot of these in our house up in Lindstrom MN. Is it a fishing spider?

dark fishing spider

 
  Jordan Plotz
6/4/2020

Location: Pelican Rapids MN in Ottertail County

dark fishing spider

 
  Marie Erickson
6/2/2020

Location: Side Lake, MN

It zipped across the kitchen floor! Sucked it up in my Dyson. A friend had one the next day near her foundation. Both at cabins near the lake!

dark fishing spider

 
  Anonymous 3
5/27/2020

Location: Bathroom wall in my house, Winona, Mn, in town

Hit my arm, scared me half to death!

dark fishing spider

 
  Steve Marquardt
9/25/2018

Location: Kandiyohi County

on driveway apron, outside of garage.

dark fishing spider

 
  Annette Pallesen
9/2/2018

Location: Pine City, Canyon Way

dark fishing spider

 
  Michele Lloyd
7/16/2017

Location: Bloomington, MN

On the inside of the screen of our sliding glass door. I am assuming that is her egg sac.

dark fishing spider

 
  Kimberly Anderson
6/9/2017

Location: At the edge of St. Croix State Forest, just south of Highway 48.

Nearest body of water was at least 200 feet away.  Found one the weekend before in an outhouse in the same general area

 
  Brian Johnson
6/18/2015

Location: Northern St. Louis County near a small lake.

This spider was in the tall grass. The span of the legs was close to 90 mm. The body close to 30 mm.

dark fishing spider

 
           
 
MinnesotaSeasons.com Sightings
 
 

 

 

 

 

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