Readers’ wildlife photos

February 9, 2021 • 8:00 am

I have a bad feeling about running out of photos, so now is the time to send them in!

Today we have the second part of Mark Sturtevant’s February 4 post on a spider that lives on water lilies and eats fish. Have a look at the earlier post first, then this one. Mark’s notes are indented, and you can enlarge the photos by clicking on them.

I had recently introduced the six-spotted fishing spider (Dolomedes triton). This species is widespread, and can be found on floating vegetation on lakes and ponds or on river areas with minimal current. From there they will hunt a variety of prey, including small fish. This will be a special post since it is that latter talent that you will see today.

I had brought home a fishing spider, and she was kept for a time in a glass-bottomed aquarium with water and some lily pads. Here she is again. For scale, her leg span was a bit over 2 inches. They do get larger.

The aquarium was put in my backyard for a time, and I could park myself underneath it to photograph activities from below. One tries not to imagine what the neighbors were thinking. Minnows (fishing spider food) were introduced, and I really had no idea if she would even go hunting for one. But from time to time she would extend her legs out onto the water. As I understand it, this is how they monitor for moving prey below, so that was encouraging.

By the way, all of these pictures from the underside were extensively processed since I had put a screen cover over the aquarium to keep her inside while I was directly below. The screen was plainly visible in the pictures, though, so it had to be digitally removed. That was a lot of work!

Anyway, it took a little while, but then something started to happen. At this point I was freaking out!

The actual attack was very fast, and these are among the few pictures that I have of it. What I saw was that the spider strode out onto the water, and suddenly “clawed down” to gather up the fish before retreating quickly back to the lily pad.

The shadow tells the tale.

Here she is again up top. The photographs were taken through glass which was by now rather steamy with the summer heat, and so the pictures required some de-hazing treatments in post-processing to rescue them.

She was deftly turning her prey over and over with her chelicerae and pedipalps, working in the venom. In just a few minutes the tissue dissolving effect of spider venom was very obvious.

Fishing spider hunting has been captured in video. Here are two examples. They really seem to go after fish! [JAC: don’t miss these videos!]

and

Thanks for looking!

21 thoughts on “Readers’ wildlife photos

  1. I know how the lighting would trash a photo like those – and how beautiful these came out, with the footprints – beautiful! Worthwhile effort!

  2. Your photos and explanations are wonderful! Yet another reason to look forward to summer! But oi — the narration, music, and sound effects on that Smithsonian Channel clip were painful!

    1. Smithsonian was most anti educational with their scare tactics. Heaven only knows what they wold do with a seriously harmful creature.

    1. Mainly Gimp, which is free but powerful. To remove the screen I did a Gaussian blur to obliterate all details in a picture. The focused parts and the floaty things in the water were then put back in from an original picture from a different layer with the help of a layer mask. Lots of touching up followed with cloning and healing brushes. This took a couple hours for each picture. To de-haze, I used Photoshop Elements. Breathed a sigh of relief when I saw it was doing the trick.

  3. I had brought home a fishing spider…

    My daughter is an arachnophobe, probably clinically certifiable Stage 4 (like in cancer, if they have those kind of ratings). Just reading that phrase would probably put her in a cold sweat. She once ran screaming out of the house when a friend of hers showed her some mummified spiders in webs in the back of a grandfather clock. It is so sad to my bio-oriented self. I used to send her posts like these to try to de-sensitize her but finally gave up.

    Astonishing how gorilla-face-like that last one is. Aposematic? Convergent evolution? Pareidolia?

    1. Well, she definitely won’t like the descriptions planned for the 3rd post coming up later. Photographing the spider in the dark on my dining room table! I was a bit scared, even.
      The fishing spider has these prominent brow ridges over their lateral eyes, which you can sort of see in the last picture.

      Try small jumping spiders. The are adorable, and they really cannot bite you even if they wanted to (and I promise they won’t want to).

      1. Thx. She’d be gone at “jumping spider”.

        Meanwhile, I’m a big fan of the Spider Silk book. There’s one whose description near/at the end of the book (copy of which not presently at hand) fascinated me. It glues its silk to the bottom substrate, puts some goo on the silk, goes overhead, pulls the silk taut, and waits until a prey ambles past, gets glued to the silk, and Thwang! the silk breaks flinging the prey into the clutches of the spider. Just in case you have any pix of such spiders.

  4. I was looking forward to these, and they were not a disappointment. Far from it! Magnificent series.

    “In just a few minutes the tissue dissolving effect of spider venom was very obvious.“ Indeed. 😳

  5. Just a wonderful series and very inspiring. I’ve been wanting to set up some dioramas for behaviour shots. Great work on the post processing too. I know how tedious and rewarding it can be.

  6. So you were outdoors, lying under an aquarium with a glass bottom, photographing this magnificent spider, which you captured, and which you supplied with appropriate minnows — in natural light. Is that right? Well done!

    I feel sorry for the vertebrates in these cross-phylum combats. Call it phylism or phylophobia. I please guilty.

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