Interesting info. Thanks for sharing.

Hey FNP, THx for the info. Im keenly interested in this topic. Is there a source for your info that I can read more from? Thx in advance.

Doc,

I remember some good stuff from my Marine Bio. days back in college about squid and octopus eyes, especially how close they are to ours. Any interesting stuff to tell about them?

Fish on...

Todd.

John B, there is a book called "What Fish See" by Kageyama its published by Amato Publication.

Rgards

IB

Thx IB, I agree, the Kegeyama book the definitive source!

There just doesnt seem to be much else around. Was hoping to read some new stuff.

PNG stuff above is good - would like to read more. thx

Interesting facts. Thanks for sharing.

A true pupil of the game....no pun intended.

Interesting enough. Thanks. But how do they taste?

Interesting. I like the fact about how they look down since most people say that fish look up.

cut plug: You might want to try resizing you avatar with photo shop or something.

edit: I see you where one step ahead of me cut pug.

My dad's only reference to fish eye's was simple....."Fish don't have eyelids." reminding me, as a kid, to pay more attention to shady spots than those in sunlight.

Personal observation.....fish may have the ability to look downward, but if you have ever watched fish, they almost always turn on their side to watch things beneath them. The other option they use frequently in the salt is to stand on their head.

Those gill plate rakings on bottom-feeding chinook also show that they will dig out their prey (candle fish) after lying on their side observing them.

Here's another thing to think about - fish eyes do not iris, and though they can see much better in the dark than we can, they can only adapt their eyes to changes in light by chemically activating or deactivating rods and cones in their eyes, and do so at about the speed that the sun rises and sets. Think of this as stepping into a darkened theater and taking an hour for your eyes to adjust enough to find a seat. This has implications for escape from predators in the unnatural situations we build for them - like continuous pier aprons in our industrial waterways. Why do those Green River fish runs seem to be failing? Well, picture this, downstream come the smolts and they run into a pier. They can't see under it so they go around it. They are then in deep water where diving ducks can attack them from all sides and push them against that black hole that is the unnatural shadow under the pier where they can't see and the diving ducks, who's eyes iris, can. Same for returning adults, this time it's the seals who bottle them up against vertical riprapped shorelines and pier aprons and feed away. The fish don't have anywhere to run or hide and they don't have a chance. All the harvest and hatchery impacts pale in comparison to the habitat impacts in this situation

Spawnout

Are you sure about that last post? Sounds a little far fetched to me, but I honestly can't say with certainty.

One thing is for sure, though.... salmonids have an iris. It may not be blue or brown like yours and mine, but it's there. Kind of a silvery gold color but sometimes a darker gold. If this piece of eye anatomy is present, it must serve some useful purpose.... namely as a diaphragm to control the absolute amount of light allowed to pass thru the pupil (the dark hole in the middle of the iris), just like in our own eyes.

I have never examined a living piscine patient's pupillary reaction before (never had a reason to) but I can assure you that the pupil has the ability to constrict.... just look at any dead fish photo for proof. The pupil in a living fish almost has a fat tear-drop or watermelon-seed appearance. The pupil in a dead fish is perfectly round, very small and beady, accentuating its lifeless appearance.

The real question is whether the pupil constricts in a living specimen. Will have to check that one out. Problem is I have to catch a fish first... been on a long drought for far longer than I care to admit.

Here's a couple pic's to illustrate some of the points above..

Dead dink with small pupil.



Compare that with this live hawg with normal pupil.


Big difference, huh!? BTW the buck in the top pic weighed just shy of 10# while the one on the bottom was estimated at 45#.

Good thread FNP