Fishing Spider: Molting or Mating???

Fishing Spider – Dolomedes scriptus?
May 25, 2010
Searched tons of images and dolomedes scriptus is the closest I can find. It appears the 2 spiders mated and the female consumed the male. The 2 of them were hanging from the flagstone at the edge of our pond. I also have a short 10 second video I shot of them.
R. Kitchen
Angus, Ontario

Molting Fishing Spider

Dear R. Kitchen,
Wow, these photos are awesome.  We believe you have correctly identified these Fishing Spiders as Dolomedes scriptus based on images and information on BugGuide.  At first we ran with your mating and cannibalism scenario, but upon closer inspection, we believe you have documented the aftermath of a Fishing Spider molting.  Spiders do not mate like insects do.  Rather, a male spider transfers his spermatazoa to the female with his pedipalps.  We would really love to get feedback from an arachnologist regarding your documentation.  We have yet to post any videos to our website, and if you would like to submit your video, we will discuss the matter with our webmaster as to how best to showcase it on our site.  Thank you again for submitting these phenomenal images.

Molting Fishing Spider

Thanks to everyone who corrected our error.  In our haste to post this letter and photos, we incorrectly indicated that the male transfers his spermatozoa with chelicera rather than his pedipalps.  We have made the correction.

Very cool!  Yes, a molting Dolomedes species….By the way, males transfer sperm with their “pedipalps,” not their jaws!

Thanks Daniel for the quick response. It makes a lot more sense and explains why what looked like the other spiders head was on it’s back. The husk was just skin when I inspected it. I also lifted a rock and found a smaller, older husk.
Wish I had more water striders in my pond for it to feed on (ther’s only one). It’s sitting there just waiting for something to pass by.
How should I get the video in and would you have a preferred format?
I’m also taking some more shots of it if you’re interested.

Hi Richard,
Our website traffic has suddenly spiked, and there are many unanswered letters in our mailbox right now.  If the photos you take are awesome, try sending them, and hopefully we will be able to post them.

Fishing Spider

Attached are 2 additional images showing the spider head on.

Fishing Spider

2 thoughts on “Fishing Spider: Molting or Mating???”

  1. I have no doubts: is a molting spider, the position of the hanging old exoskeleton is typical. You can see clearly the old carapace still on the spider`s abdomen.
    And a little explanation: male spiders don`t use chelicera to copulate, they use the palps (they are leglike but smaller and with its tip enlarged in males) to transfer sperm. I believe the spider is a male, you can see one palp with its enlarged tip, just in front of the head and between the first pair of legs
    The pictures are great!!


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