Those Eyes

Could a greater miracle take place than for us to look through each other’s eyes for an instant?

~Henry David Thoreau

On any woodland walk in the warm months, you will run into a variety of spider silk across your path. And so it was recently on a walk in our woods. It was mostly webs of small orb web weavers strung across the trail, but at one point I found myself staring at a spider dangling at eye level. I reached for it and realized the spider was no longer there, just its last set of clothes – a shed exoskeleton.
spider shed

Spider shed that was hanging by a thread along the trail (click photos to enlarge)

I am always fascinated by the remains of insect and spider sheds. The lighter-than-air remains cause them to dance in the slightest breeze, but the detail of their former inhabitants are so revealing and beautiful. In spiders, they have a pop-top shedding style so the cephalothorax is removed like a can lid so the “new” spider can pull itself out of the tangle of old leggings.

spider shed on moss

The eye coverings remain on the shed head seen on the left in photo

When I touched it for a closer look, the shed dropped to the ground and landed on a mossy rock. It looked as if the spider was ready to run off again, but with its head oddly trailing behind.

As we approached the house, I checked the small pawpaw patch out back and noticed something disappear under the broad leaves of a small sapling. I eased my hand under the leaf and a spider popped back out on the upper surface.

Magnolia green jumper male 2

Magnolia green jumper on pawpaw leaf

And what a spider it was! I have photographed the female of this species, a magnolia green jumper, but had never seen a male. They are characterized by the two huge eyes in front and their insanely long chelicerae.

Magnolia green jumper male under leaf

The magnolia green jumper under the leaf

This little guy was quite active and bold. I had to coax it out from under a leaf at first, but then it tended to move toward the camera and even jumped on the lens a few times. I would then ease it back onto a leaf and start the photography dance all over again.

Magnolia green jumper male eye arrangement

There are four rows of two eyes each, with the two in front being very large

Both sexes have a raised “eye mound” with 8 eyes surrounded by orange. These spiders can scan the area in front of them by moving the rear of their lens (the actual “eyeball” is fixed since it is built into the carapace). Because the rear of the lens is the darkest part of the eye and it moves around, you can often see a jumping spider’s eye changing color as in the photos below. When it is darkest, the spider is looking straight at you, because then you are looking down into its retina.

 

Magnolia green jumper male eye closeup 1

The retina sweeping side to side in the eye

This series of photos also shows the chelicerae (jaws) – the brownish orange appendages coming out beneath the eyes. Coming down on either side of those are the pedipalps (or palps).

Magnolia green jumper male eye closeup

One eye dark, one lighter

Pedipalps resemble small legs, but, in males, they serve a reproductive function.

Magnolia green jumper male eye closeup 2

Here’s looking at you…

The tips of male pedipalps are modified with small swellings (that look like small boxing gloves) that contain a complex copulatory organ. Males deposit sperm from under their abdomen into a small sperm web and the then suck it up into the palpal organ. When he finds a receptive female, he inserts the palpal organ into a slit on her abdomen and squeezes out the sperm. I suppose it is safer that way considering she might want to make a meal of him. Probably another reason to have a lot of eyes if you are a spider.

 

6 thoughts on “Those Eyes

  1. Mike, you are full of fascinating information I would probably never have cause to look up and would otherwise never know. Thanks you for sharing! I sometimes see these spiders and note they look different, but both me and the spiders move on. You help fill an information void I didn’t realize was there.

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