Originally Posted by
Douglas
As you know, I target wild barramundi and king threadfin. Fitzroy is a notoriously dirty water river and I've been looking at what I could find about barra and king eyesight and lateral line sensors.
Barra have always been a bit of a mystery with their pinky/red eyes. Some believe its infrared sight.
Its not infrared but simply the result of colour given off as light is reflected back through the eye twice.
Barra do this to make up for the effects of dirty water or other low light conditions.
But that only works when they can actually get within visible range which is usually very close in this river.
So there must be another mechanism that gets them within vision range.
It has to be the result of lateral line data sent to the brain.
The more I searched for info on lateral lines, I began to understand how predator fish rely on lateral lines.
The sensors in the lateral lines (called neuromasts) process incoming vibrations in the water and tell the brain the direction of the source.
A bit like a "steer left or right" signal which allows the fish to home in on food that produces vibrations in the water.
The steering direction brings the fish into vision range to the point where the eyes then take over for the strike.
That explained a few things to me like barra preference for live bait (fish or prawns) because they produce vibrations by movement which the lateral lines pick up. Very seldom do you catch a barra on a dead prawn or dead fish bait. No movement therefore no vibrations unless you provide some movement. I'll come back to that.
That meant that attracting a barra strike was a two stage process. The lateral line role and then the eyesight role.
I've had a bit of a play around with what I consider to be those two processes over the last few weeks.
Anybody had a look at this subject at all?