How do fish see and navigate in murky water?

[Arbutis]

This is a subject that has been bugging me lately. After doing a bit of my own internet research I have come up with a lot of dead ends. Maybe someone here has other information about this subject.

I do some spearfishing from time to time as well as some underwater video. I frequently encounter murky (dirty, dingy, muddy, silty - whatever you want to call it) water in our lovely state of New Jersey. This obviously cuts a spearfishing outing or video session quite short. However, I know from my fishing experiences that they are still quite active and able to be caught in these types of water conditions.

A lot of the internet research turned up information about the lateral line, the sense of smell, electro-receptors, rods and cones, the different wavelengths of light and how it penetrates below the surface of the water and at depth, etc, etc - but that's not exactly what I'm looking for.

I may be searching for something that is unknown to us but what I'm trying to figure out is how fish can navigate and live their lives in water that is virtually opaque to the human eye. The bays and rivers in our area (and even the nearshore ocean most of the time) are perpetually murky - yet they are loaded with all kinds of fish an sea life. I shot some video the other day and could barely see a lure as it passed within 6 inches from my camera. Yet the fish can see, navigate, forage for food and live in this environment - day and night. It's got me thinking that their eyes must be specifically evolved to see through this murk. But how? and what do they actually see?

Well, just curious - in case anyone out there can shed some light on this perplexing question.

[spyro]

same ay they do in clear water ....

[arat]

In response to your lure passing the camera comment. The fish can probably feel the water that water is pushing and hear the disturbance it cause. Probably don't need to see it. The other question I can't answer

[Jigman13]

1.) diff eyes, evolved over millions of yrs, absorb light much differently than the human eye. Larger pupils, etc etc.
2.) lateral line: helps fish detect movement and vibration while under water
3.) neuromasts: part of the lateral line--help detect changes in the water
4.) smell: just like sight, evolution plays a major part in how fish "smell" underwater, too.

Research the functions on the lateral line system in fish and it should give you an idea of how fish detect, cope, and feed in waters lacking clarity.

[makokeith]

Fish see UV in low light conditions too.

[Arbutis]

Originally Posted by Jigman13

1.) diff eyes, evolved over millions of yrs, absorb light much differently than the human eye. Larger pupils, etc etc.
2.) lateral line: helps fish detect movement and vibration while under water
3.) neuromasts: part of the lateral line--help detect changes in the water
4.) smell: just like sight, evolution plays a major part in how fish "smell" underwater, too.

Research the functions on the lateral line system in fish and it should give you an idea of how fish detect, cope, and feed in waters lacking clarity.

I agree with 1.) - makes sense. I mean, they breathe underwater too - we just accept that because it's obvious and we have a basic understanding of how their gills work differently from our lungs. Their eyes have evolved differently than ours as well and without actually "seeing" what they see, I don't think we can do anything but guess about this question.

Maybe they see like The Predator (from the movie) - something different all together outside the visible light spectrum. Seems odd in a liquid and murky environment - but what's odder than breathing water? They live there so they must have some ability to navigate without bumping into dock pilings and rocks all the time when the water is murky.

[tjd24]

Lateral Line and sense of smell!
Think about how the blind cave fish survives.

[DarkSkies]

Originally Posted by Arbutis

I may be searching for something that is unknown to us but what I'm trying to figure out is how fish can navigate and live their lives in water that is virtually opaque to the human eye. The bays and rivers in our area (and even the nearshore ocean most of the time) are perpetually murky - yet they are loaded with all kinds of fish an sea life. I shot some video the other day and could barely see a lure as it passed within 6 inches from my camera. Yet the fish can see, navigate, forage for food and live in this environment - day and night. It's got me thinking that their eyes must be specifically evolved to see through this murk. But how? and what do they actually see?

Well, just curious - in case anyone out there can shed some light on this perplexing question.

Doug, some of this may be helpful. A while back I started a thread on striped bass sense of smell, olfactory ability. Do a google search for:

"Striped bass: Sense of smell, olfactory ability


As for the vision of the bass and the coloreceptor theory, a friend of mine was talking about that......
Do a google search for:

"Striped bass: Sense of vision, Vision ability"

Hope that answers some of your questions.

BTW, the handle "Arbutis"......you don't live in Staten Island by any chance, do ya? Ever fish down by Arbutis Ave?