How do you tell what kind of fish they are?

Discussion in 'Fish Finder Review and Study' started by spoonfish, Feb 12, 2008.

  1. spoonfish

    spoonfish New Member

    Messages:
    3,780
    State:
    Warsaw, Mo.
    Ok, I know a lot of guys say they can tell on there electronics the difference in fish species. I'm intrested in hearing everyones opinions. What are you looking for, different colors on color finders, echos, relationship of depth, size, structure, ect.
     
  2. spoonfish

    spoonfish New Member

    Messages:
    3,780
    State:
    Warsaw, Mo.
    Also would like to hear from anyone who is useing the new hummingbird si units. Is there a way to tell while useing the side image or are all the images the same except for the size?
     

  3. Mr.T

    Mr.T Active Member

    Messages:
    2,554
    State:
    MO
    Well, on my color fish finder, the blue cats are blue, the yellow cats are yellow, the brown trout are brown and the rainbow trout are all different colors... :roll_eyes:

    Bottom line is, you can't tell much about what specific kind of fish you're seeing, based *solely* on the echo painted on your screen. You can take the location and size of the echo and make an educated guess, but that's all it is -- a guess. Even the size of the echo is misleading - when the boat is moving slowly, past a fish, the echo will be bigger than when the boat is moving more quickly, often leading you to the (wrong) conclusion that you're seeing a bigger fish.

    Some folks swear they can tell the difference between scaled vs. smooth skinned fish based on the shape and size of the echo. Personally, I doubt it: Sonar works by bouncing sound waves off of "things" that are of a different density than the water they're in. Nearly all of the echo that we call "a fish" results from the sound waves bouncing off of the air bladder in the fish, not the skin, scales or bones -- all of which are very close to the same density as water and thus won't create much of an echo. The air in the air bladder is radically different in density than the water around it, and thus makes for a stronger echo.
     
  4. TDawgNOk

    TDawgNOk Gathering Monitor (Instigator)

    Messages:
    3,365
    State:
    Tulsa, Oklahoma
    Troy, the way it was explained to me, and from the images that I saw is:

    If a color unit is finely tuned, you can tell the differance in scaled fish vs non scaled by the color. Scaled fish will be more of a reddish tone, where non scaled have a more yellow color. This was shown to me on images where there was a school of bait fish, below that some scaled fish, and then below that, some non scaled. This information comes from a long time guide who is extremely knowledgeable. He took this information to lowrance, and they are pooring over the data that he has collected over the past few years.
     
  5. BKS72

    BKS72 New Member

    Messages:
    3,361
    State:
    East of KC
    Troy I can't tell what kind of fish is what on the side image, other than by educated guesses. If I'm in slack water behind a dyke and see a lot of big returns in the water column, I'll bet my next paycheck they're probably Asian carp. On Smithville every now and then I'll see fish hovering around a submerged tree. Not sure if they're bass or crappie, but you get the idea, you can kind of make an educated guess about what they are by the location and structure. But then again they could be suspended blues around that tree for all I know. I have yet to see a fish sucked tight to the bottom, but last summer was my first season with it, I think I'll get better at reading it the more I use it. Last summer was more figuring out the buttons and settings, I'll devote a lot more time this year to interpreting the images.

    Side image for me comes into play by allowing me to see structure as it really is - I can tell the top of a tree layed over on it's side in the river from the rootball and get a distance and heading to it from my cursor. I can see the ripples in a sandbar, or rocks/stumps/humps on a sandbar and be 95% sure they are what I think they are based on the shape and intensity or brightness of the return.

    I'll drop you a line when I get the boat back on the water and maybe I'll meet up with you down on Truman or we can hit the river and you can get an idea of what they will and won't do (if you don't have one already by then:smile2:)
     
  6. Stubby

    Stubby New Member

    Messages:
    208
    State:
    Kansas, Ar
    Brandon at what depth do you feel that it is helping you read the structure. 5-10-20 feet. You do have the 797 right? Some of the guys say they are reading a kind of echo off of the scale fish and none off of the skin fish.
     
  7. rspd507

    rspd507 New Member

    Messages:
    729
    State:
    Rising Sun,IN
    Troy,
    Here is a thread posted by Eric (Deerhunter01) explaining how he could tell the difference between scaled and non scaled fish on his old unit. I just bought this unit the x-135 and it helped me tremendously. I really believe at least with this unit you can tell the difference. Here is the link to the article.

    rspd507

    http://www.catfish1.com/forums/showthread.php?t=69177
     
  8. biga

    biga Well-Known Member

    Messages:
    2,112
    State:
    evansville
    i agree with ross and dh on this... on my x135 most of the fish you see suspended show the longer - thinner bow echos [[probably carp or stripper ]] and abigol fatcat laying on the bottom thicker more defined arch and may have a fish 5 foot from him with that longer echo so i dont see it being related to the depth of the fish... the air bladder thing just doesnt add up to me.... i would need to hear an educated agrument because thats sure not how sonar was ever explained to me...
     
  9. Seth

    Seth Active Member

    Messages:
    1,807
    State:
    Owensville, MO
    What would cause the scaled fish to have a pencil line coming off of the fish arch? I always thought that if it had a sharp drop off that the fish was just swimming away from the transducer area quickly.