æʃliŋ, purrepurrocessor @aescling@cat.family

That moment when you and the cat take turns slow blinking at each other

VictoriaCat_027

A fluffy belly #caturday #chamedi

also if you don't like xenia being my t4t girlfriend and linux being inherently transgender, i'm sorry to say, but the moon is also my wife

1134324726465

Tiny tater. Ca. 1935. #CatsOfYore #Cat #Cats #History #catsodon #catsofmastodon #catcontent #ilovecats #vintage #kitten https://www.artsy.net/artwork/dora-maar-savoie-cat-chat-savoie-iii-1

🚨🚨🚨

​

Your timeline has been placed under a Kitten Warning. A kitn has been sighted in your area. Please take necessary preparations.

Your timeline has been placed under a Kitten Watch. Be alert! Conditions are favorable for a kitn to appear.

so, i saw some really good spider pics recently, which i'll link to here:
https://toot.community/@Rihilism/110985643620069696
https://toot.community/@Rihilism/110985674599670068

and i wanna talk about one of my favorite things about jumping spiders (which i'll be calling salticids in the rest of this post), which is their distinct eye pattern. You may know already that their front eyes are two big ones, then two little ones on the outside of that. but spiders usually have 8 eyes, and it begs the question: where are the other 4?

well! let's dig in.
first of all, the big front eyes are called the anterior medial eyes. these are the real powerhouse in terms of active sight - they have a tight vision cone and tetrachromatic vision (they can probably see into the UV range!) with a second lens inside the eye. The eyes are too close together for useful depth perception, so they *defocus their eyes* to figure out depth because the light receptors in their eyes are deeper for different colors. Rather than moving the externally facing eye, they move the retina to track things - There are salticids with translucent carapaces where you can actually see the interior of the eye moving when they're tracking prey!

That second pair of eyes you've probably seen are the anterior *lateral* eyes! These have good enough vision to recognize shapes, and are far enough apart for depth perception - there are salticids in a study who were able to stalk and catch flies with only the use of their anterior lateral eyes. Their low detail vision comes with a very wide vision cone, which helps with that stalking!

now, on to the crops i've attached to this post with permission (thanks again @Rihilism !!!) - Here, you can see the anterior medial and lateral eyes very clearly, but then, the *posterior* lateral and medial eyes. The posterior medial eye is that smaller, partly obscured by fur black shiny spot in the first image. Frequently, this one's vestigial, but in some species it is bigger and is used to sense motion!

but the big kicker, the thing that gives salticids their near-360 degree lateral vision, is the posterior lateral eyes, the big chunky ones near the back. if you've ever tried to like, catch a jumping spider or shoo it onto some paper, you'll know that they Can Tell When Something Is Moving Behind Them - these eyes are basically motion detectors, like the PMEs when they're not vestigial. i presume that JoJo's Bizarre Adventure characters also have posterior lateral eyes, honestly.

the posterior eyes are frequently (from what i've seen!) placed such that the wide angle vision also benefits them in 3d space - you can see on this specimen that the PLEs are facing backward and upward, so it's not just 360 degree vision, you could probably map it onto a sphere. (i'm... now extremely curious if someone's already done this)

now you know where the other 4 eyes are!! and why they're so cool! there's a Reason salticids have things like complex mating behaviors, bright color patterns, hunting over web-building, etc. i like to think of them like birds and cats, they're v v neat.

#spiders #arachnids

Snow leopard!

*does not have a single thought in its head* ​