The eyes of cats

W

water

the sea
Registered Senior Member
I am curious: How come that big cats (tigers, lions, panthers, cheethas, ...) have round eye pupils, while domestic cats have pupils in the shape of a slit?

How closely are domestic cats related to big cats then?

If they had a common ancestor -- what shape of the eye pupil did that animal have? And why the different evolution?
 
I would think that the big cats have round pupils because they tend to hunt at night as well as day and to hunt in the dark there pupils must be bigger than a domesticated cat seeing as they dont usually have to hunt for there food, let alone at night.
 
When a house kitty is angry/interested/sits in the dark, his pupils dilate and turn into circles, gradually.
 
Animals that have pupils that go verticle are nocturnal. Horizontal and round pupils desidnate diurnal creatures.
 
Enigma'07 said:
Animals that have pupils that go verticle are nocturnal. Horizontal and round pupils desidnate diurnal creatures.
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Not necessarily. As far as I know, all rodents have round pupils, and some rodents are nocturnal animals. Owls have round pupils. Also even some of the big cats are active in the night.
There must be some other explanation.
 
J.C. is right most big cats are more active at night(discovery ch.) , i would think thats why they have round pupils. Isnt it the rounder the pupils the more light gets in which nocturnal animals need to see in the dark?
 
Never mind what I said above. It appplies only to reptiles and amphibians. sorry for the confusion.
 
RosaMagika said:
I am curious: How come that big cats (tigers, lions, panthers, cheethas, ...) have round eye pupils, while domestic cats have pupils in the shape of a slit?

How closely are domestic cats related to big cats then?

If they had a common ancestor -- what shape of the eye pupil did that animal have? And why the different evolution?
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Felis cattus is most closely related to the other species in the genus Felis. That includes mostly small cats like the African wild cat (that looks almost like a domestic tabby) but also the American mountain lion, Felis concolor. Go figure!

The biggest cats are in genus Panthera, which is more distantly related to Felis. The lion is Panthera leo and the tiger is Panthera tigris. The other felines are scattered throughout several other genera such as Leopardus, which includes both the leopard and the ocelot, and Lynx, which includes the lynx and the bobcat.

What I don't understand is that the definition of a genus has changed since I was in high school 45 years ago. Back then it meant a group of species that could interbreed. Well, domestic cats and ocelots interbreed readily. You can find ocicats in the classified ads of any big city newspaper. (So if you're having trouble with a mean dog in your neighborhood. . . .) So how can they be in two different species? In my youth, even lions and tigers were classified in genus Felis. DNA analysis has made it possible to classify species more precisely, but it has blown the nice neat definitions that we used to work with.

The common ancestor of all the cats was actually a doglike creature. The first carnivores were primitive dogs. The other families of carnivores -- the cats, hyenas, bears, etc. -- all split off from the dog family along the way.

I'll leave the pupil thing to you folks. I always thought lions had slitted pupils too.
 
It seems to me that the house kitty goes more along with the master's sleep cycle. However, I had a non-neutered kitty once, and he slept during the day and tortured the house all night long.

Yes, the round pupil lets in more light than the skinny oval one.
 
Thanks for the replies, folks. :)

As far as I know, a round pupil is just as effective as a pupil in the shape of a slit when it comes to the amount of light that passes through the eye lense.

It could be that the shape of the pupil is yet another variable thing -- like the the number of heart parts or something like that. But we need a biologist on that.


Fraggle Rocker,

What pupils do ocicats have?
 
and goats have rectangular pupils, I wonder why?

Here a good sight answer the cat question at least:
http://ebiomedia.com/gall/eyes/nocturnal.html
But by day, the circular pupil is inefficient at blocking light. Instead, a variety of pupil shapes have evolved that limit incoming light, the most advanced being the vertical slit. The slit pupil can shut out all light except a narrow band. Its vertical orientation is of significance too, as it works well with eyelids. As an animal squints, partially closing its lids at right angles to the vertical slit pupil, it further reduces the amount of light entering its eye. Perhaps the most noteworthy of all pupils is the stenopeic pupil of the gecko, a vertical slit lined with notches on each margin. When the pupil is entirely closed, tiny pinholes allow light to pass through to the retina creating sharp overlapping images.
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I mean it is strange: Goats and sheep don't seem to be that far from cows -- but their eyes are so different.
 
It seems to me that the house kitty goes more along with the master's sleep cycle. However, I had a non-neutered kitty once, and he slept during the day and tortured the house all night long.
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I have a house cat that is fixed and the thing is wild! It sleeps all day long, and the when I'm ready to go to bed it thinks it's play time, as in time for an all night long party running up and down the halls and climbing on the counter tops.
 
Many well-domesticated cats don't have regular sleeping schedules, neither do they have a regular place where they like to sleep.

I would know. By now, I am as trained as a circus animal.
 
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