dark fishing spider

(Dolomedes tenebrosus)

Conservation Status

IUCN Red List

not yet assessed

dark fishing spider


NNR - Unranked


not listed


Regularly occurring


Early May through September


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


Male: ¼ to ½
Female: to 1



          Photo by Brian Johnson


This is a large, robust, nursery web spider. It is the largest fishing spider.

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.


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.


Large insects and small vertebrates

Life Cycle

These spiders reproduce 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.


These spiders are most often seen perched vertically. They hunt for prey mostly at night, remaining motionless on a tree trunk, wall, or other vertical surface.

Distribution Distribution Map   Sources: 24, 29, 30.





Araneae (spiders)





No Rank:

Entelegynae (eight-eyed spiders)


No Rank:

RTA clade






Pisauridae (nursery web spiders)




a fishing spider

brownish-gray fishing spider

dark fishing spider

fishing spider










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



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.



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



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.

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






  Fishing Spider (Dolomedes tenebrosus)
Bill Keim
  Fishing Spider (Dolomedes tenebrosus)  
  Dolomedes tenebrosus (Dark Fishing Spider)
Allen Chartier
  Dolomedes tenebrosus (Dark Fishing Spider)  




Visitor Videos

Share your video of this arachnid.


Other Videos

  Video S1
Royal Society journal supplements

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

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

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

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

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.

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The Dark Fishing spider’s Deadly Mating Game - ScienceTake





Visitor Sightings

Report a sighting of this arachnid.

Steve Marquardt

Location: Kandiyohi County

on driveway apron, outside of garage.

dark fishing spider

Annette Pallesen

Location: Pine City, Canyon Way

dark fishing spider

Michele Lloyd

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

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

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


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