(Dolomedes tenebrosus)
Conservation Status | IUCN Red List |
not yet assessed |
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NatureServe |
NNR - Unranked |
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Minnesota |
not listed |
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Occurrence | Regularly occurring |
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Season | Early May through September |
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Habitat | Deciduous forests, often far from water; human houses near deciduous forests. |
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Size | Male: ¼″ to ½″ |
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Photo by Brian Johnson | |||||||
Identification | This is a large, robust, nursery web spider. It is the largest fishing spider. The adult female body is ⅝″ 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. |
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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. |
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Food | Large insects and small vertebrates |
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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 ⅝″ 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. |
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Behavior | 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. |
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Distribution | ![]() |
Sources: 24, 29, 30. | |||||
Comments |
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Taxonomy | Order: |
Araneae (spiders) |
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Suborder: |
Araneomorphae |
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No Rank: |
Entelegynae (eight-eyed spiders) |
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No Rank: |
RTA clade |
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Superfamily: |
Lycosoidea |
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Family: |
Pisauridae (nursery web spiders) |
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Synonyms |
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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 | |||
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NorthernMNmom | |||
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Jason Halverson | |||
found it under the grill cover outside. |
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Benjamin Merk | |||
We have a lot of these in our house up in Lindstrom MN. Is it a fishing spider? |
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Jordan Plotz | |||
Caught in Pelican Rapids MN in Ottertail County |
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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! |
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Anonymous 3 | |||
Hit my arm, scared me half to death! |
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Jamie Miller | |||
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Steve Marquardt | |||
on driveway apron, outside of garage. |
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Annette Pallesen | |||
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Michele Lloyd | |||
On the inside of the screen of our sliding glass door. I am assuming that is her egg sac. |
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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. |
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MinnesotaSeasons.com Photos | |||
Slideshows | ||
Fishing Spider (Dolomedes tenebrosus) Bill Keim |
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Dolomedes tenebrosus (Dark Fishing Spider) Allen Chartier |
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Visitor Videos | |||
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Other Videos | |||
Video S1 Royal Society journal supplements |
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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 |
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Dolomedes Tenebrosus Mating Silka Buns |
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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 |
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Dolomedes Tenebrosus - Brownish Grey Fishing Spider HD trumansnare |
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About
Uploaded on Jan 20, 2011 Brownish-Grey Fishing Spider (Dolomedes Tenebrosus) 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: Camera D-SLR: |
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Dark Fishing Spider (Pisauridae: Dolomedes tenebrosus) on Fence Carl Barrentine |
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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! |
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The Dark Fishing spider’s Deadly Mating Game - ScienceTake | The New York Times The New York Times |
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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 Subscribe on YouTube: http://bit.ly/U8Ys7n Watch more videos at: http://nytimes.com/video --------------------------------------------------------------- Want more from The New York Times? Twitter: https://twitter.com/nytvideo Instagram: http://instagram.com/nytvideo Facebook: https://www.facebook.com/nytimes Google+: https://plus.google.com/+nytimes Whether it's reporting on conflicts abroad and political divisions at home, or covering the latest style trends and scientific developments, New York Times video journalists provide a revealing and unforgettable view of the world. It's all the news that's fit to watch. On YouTube. The Dark Fishing spider’s Deadly Mating Game - ScienceTake |
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Visitor Sightings | ||||
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This button not working for you? Simply email us at info@MinnesotaSeasons.com. Be sure to include a location. |
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Mike Saunders 7/1/2020 |
Location: Caribou Lake (Lutsen) male and female on the dock |
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NorthernMNmom 6/23/2020 |
Location: St. Louis County |
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Jason Halverson 6/21/2020 |
Location: Leech Lake, MN found it under the grill cover outside. |
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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? |
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Jordan Plotz 6/4/2020 |
Location: Pelican Rapids MN in Ottertail County |
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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! |
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Anonymous 3 5/27/2020 |
Location: Bathroom wall in my house, Winona, Mn, in town Hit my arm, scared me half to death! |
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Steve Marquardt 9/25/2018 |
Location: Kandiyohi County on driveway apron, outside of garage. |
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Annette Pallesen 9/2/2018 |
Location: Pine City, Canyon Way |
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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. |
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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 |
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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. |
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MinnesotaSeasons.com Sightings | ||||
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