Optical illusion no longer an illusion?

[Domanating]

So today I lost a male Reliosa, or more precisely currently losing. It's death came really fast from perfectly fine this morning, to collapsing in the early afternoon and finally almost dead right when I'm writing this post. As i was watching him in the early death stages I noticed the famous black spot illusion actually moving all by itself. I quickly picked up the camera and filmed the event.

Now I'm not a professional and i do not know much about the internal anatomy of the mantis but I do know that compound eyes are complex fixed structures right? They shouldn't move...

Pay close attention to the mantis' black spot in the right eye.

 

[sueb4653]

the video dosnt work for me just a white screen

 

[brancsikia339]

I've noticed that before. It is as if the eye moves with the jaw. It is similar to a kind of mental disconnection with the brain

 

[fleurdejoo]

Hhhm wow. They shouldn't move?

I have no idea. See this is why I like a large mantis.

Dude... I can barely see them at all much less their eyeballs!

But I am curious about this.

 

[Domanating]

the video dosnt work for me just a white screen

I just uploaded it so it might not work straight away. Try posting this link and see if it works.

www.youtube.com/watch?v=rELsNdNGStM&feature=youtu.be

 

[Domanating]

Hhhm wow. They shouldn't move?

I have no idea. See this is why I like a large mantis.

Dude... I can barely see them at all much less their eyeballs!

But I am curious about this.

The compound eyes basically are made of very tiny fixed eyes that together form the entire eye. In the video it looks like there's a moving eye in the compound eye.

 

[angelofdeathzz]

Yes its called the false pupil, but I've never seen it move without me in motion before. Do you have a blinking light on your camera, that may explain it?

 

[ismart]

Is there water dropplet on the eye?

 

[Domanating]

Yes its called the false pupil, but I've never seen it move without me in motion before. Do you have a blinking light on your camera, that may explain it?

The camera has no light source, except for the flash. And even if it had, I'm pretty sure that my eyes don't emit light, because that's how I spotted the pupil moving in the 1st place. Before picking up the camera I kept changing my viewing angle to see if the mind was tricking me but i still noticed the black spot twitching.

Is there water dropplet on the eye?

No water In the eye but I put a droplet in his mouth parts and that's what you see in his mouth

Edit:

And i just noticed what brancsikia339 said. The eye only twitches when the jaws are moving. It would make more sense to me if both eyes started to twitch instead of one.

 

[hopefoot]

I've got a video that clearly shows the false pupil movement. Talked to my entomologist friend and he said that compound eyes are not fully understood. My video, according to youtube, will take 170 minutes to upload and I'm going to sleep now. Will upload soon.

 

[Rick]

Your camera is moving slightly and the mantids head is moving as well. The pseudo pupil shows up at the exact pinpoint spot the viewer is looking at the eye. Since the mantids head and the camera are moving the spot appears to be moving by itself.

 

[Domanating]

Your camera is moving slightly and the mantids head is moving as well. The pseudo pupil shows up at the exact pinpoint spot the viewer is looking at the eye. Since the mantids head and the camera are moving the spot appears to be moving by itself.

The mantis only moved for 2 brief moments while I shot the footage (one at 28 seconds and another at 46). Other than that his head was perfectly still. And the camera needed to make a much more pronounced change of angle to make the pupil move that much. By the way, the shaking camera does not coincide with the pupil movements when they are more pronounced. Plus, before using the camera I was using my eyes and neither me or the mantis were moving except for his mouth parts.

When i first glimpsed this it took me a minute to get the camera. When i got back the twitching pupil stopped and so did the mouth parts. So I gave him another water droplet. As soon as the jaws started to move again, so did the pupil. There's no issue with the camera shake or the mantis moving. But there seems to be a connection between the moving mouth parts and the pupil.

 

[patrickfraser]

I think the key word is moving. Moving mouthparts? That could cause other motion in the head of the mantis. Also, unless you;re a tripod, you will have slight movement too. Even if you are completely still.

 

[Domanating]

Your skepticism is disturbing, lol.

Ok, well here's another thing I saw but this time with my female Religiosa with the prosthetic claw. I just took pics, though. No proof to post here, yet.

After witnessing the event of yesterday, I started paying more attention to the false pupil and while I watched my female eat a grasshopper, even with all the head and body motions, I could see her right eye's pupil twitching a little bit less than the male, but still jumping around. But what was intriguing was that the pupil of the left eye was perfectly still. It didn't jump around like the right pupil. I changed angles to see if there was a position that could enable me to see the left pupil moving, but i could never see it move. Only the right one did, just like the male

 

[Rick]

The head is moving or the camera is moving which changes the viewers angle of the eye, making it appear the pseudopupil is moving. The camera is anything but steady, I can clearly see it moving.

 

[MandellaMandy123]

Your camera is definitely moving, however there are no large movements of the camera which correlate with the movement of the pseudopupil. I couldn't even see the mantis' other pupil in the video. Was it moving too?

 

[Domanating]

The head is moving or the camera is moving which changes the viewers angle of the eye, making it appear the pseudopupil is moving. The camera is anything but steady, I can clearly see it moving.

Again, the camera shake is too little compared to pupil erratic movement... I guess I'll have to wait for my next mantis death to convince you people

Your camera is definitely moving, however there are no large movements of the camera which correlate with the movement of the pseudopupil. I couldn't even see the mantis' other pupil in the video. Was it moving too?

Thank you! Finally someone agrees with something!

The other pupil was not moving at all. That's why I never bothered filming it but i guess that was a mistake. If I had filmed both pupils at the same time, head movements and camera shake wouldn't even be discussed here. If these two situations were the culprits then both pupils should be moving but they weren't. Unfortunately I have no visual proof... Again.

 

[angelofdeathzz]

I think its a nervous twitch, or maybe its possessed, you may need a exorcist bud?

 

[Digger]

As I understand it, the pseudopupil illusion is created when we look directly (that is, line-of-sight), at one of the ommatidium (sing. "ommatidia"). As we shift position, of the insect does, our view down the shaft of one ommatidia cell changes to another cell, and thus that cell shaft appears dark to us. Thus, no matter how we change viewing position, as long as we have a line-of-sight view of any single ommatidia, the pseudopupil will appear to follow us. This article gives details: