A day in the Fitzroy

[BR65]

Interesting, your second post expanded on what I thought was going to be a rehash of old news.
Bit of a believer on specific sonic signatures working better than others myself.
Colours, Im undecided, tho I find myself reaching for fluro green in dirtier water 9 times out of 10, throw back to being flogged by NT guides moto of the only good lure is a 3 mt chartruese scorpion I suspect.
And yes, just when you think you have them figured out...

[Douglas]

Just sticking with vibrations in the water detected by the lateral line for a minute.

I started thinking about what actually were the vibrations that a lure makes.

With a soft plastic, that's easy. On a squidgy or hollowbelly (or any swimbait) for example, its the flapping tail. It flaps so many times per sec as its drawn through the water. But its a slow beat and not a fast beat. Low frequency of maybe 5 times a sec or less? If you want it to flap faster then speed up the retrieve.

And that's the only vibration that the lateral line can pick up of a swimbait soft plastic. Small flapping tail means that the strength of vibration available to be detected is less. The bigger the tail flapper, the stronger the vibration which means easier and more reliable the detection process.

I noticed that plastics called wedgetails and thumper tails were very successful although they didn't seem to have much action. I realised that the lack of action was made up for by the bulbous nature of the tail. Much thicker than the traditional flat tailed squidgy or hollowbelly so the stronger the vibration. Nice and simple with the lesson being the strength/magnitude of the vibration of the bulbous tail as compared to the flat tail.

So that was lesson 1 for me with the question being:

... how can I increase the strength/magnitude of the vibration coming from a swimbait soft plastic without interfering with its action?

After several unsuccessful experiments I finally realised that I'd have to use a separate vibration source. I thought of a spinner blade positioned just above the lure connection. Spinnerbaits work OK on barra. So why not just put a spinner blade on the leader about 100mm or so above the lure.

Like so...P1030005.jpg

That spinner blade produces many many times the vibration strength that the flat tail on that little squidgy. Just look at the difference in surface areas. Plus the spinner blade is spinning around a ball bearing with little friction AND at a much slower retrieve speed that barra like.

The result?... a barra 2nd cast.

The only thing that said to me was that such a rig basically shouting " here I am...here I am.." didn't deter anything. The spinner blade wasn't detrimental to the action and it didn't deter the barra.

But does it attract more strikes ?

One session isn't sufficient to draw any conclusions from so that'll take a while yet. But its encouraging so far for the lateral line theory. Maybe its a piscatorial version of cricket's bodyline.

[Douglas]

Soft vibes are dead certain candidates for a similarly mounted spinner blade.

A normal soft vibe doesn't have to swim anywhere really. Its just raised up and allowed to fall back down again with parts of the lure providing vibration (basically just the forked tail).

However, with a spinner blade, As its raised from the bottom that blade spins like crazy and the vibrations are huge. The vibrations are also maintained on the drop.

To me a similarly rigged spinner blade on a soft vibe is a bit of a no-brainer.

P1030009.jpg

Be interested to hear results if somebody had a go at that method. I've got to concentrate on the plastic swimbait testing for a little while yet.

Its simple to make up.

P1030010.jpg

That's 80lb leader with the brown float stop and no split ring on the connection to the leader. Simply straight through the bearing swivel hole with the leader. With no splitring the spinner blade is held out from the leader so as not to hit it when spinning.

[tackle_buster]

I think at the end of the day, an overall synopsis of the function of the lateral line needs to be understood. Detection of vibration is one aspect of the function, which has many uses, from the ability to school, we have all seen underwater footage of schooled up fish moving as one, detection of prey, detecting predators etc. It also detects changes in water pressure. How do these pressures change, from the gravitational pull on the earth's surface, e.g. the moon, Barometric pressure e.g. high and low. It's these changes in water pressure I believe that determines when a fish will feed and when a fish won't. READ LINK I PUT UP EARLIER TO UNDERSTAND EFFECT ON LATERAL LINE

I think we have all had the trips where we catch a fish a cast, regardless of what we throw, they just eat it. I believe this is due to STABLE high pressure weather. Then there are the trips that we would rather forget, because it didn't matter what we threw, they wouldn't bite. I believe UNSTABLE low pressure. Then you have that 10% of the anglers that catch 90% of the fish, regardless.

Why do the 10% catch more fish. Because they are the thinkers and tinkerers. It's how they catch fish when people can't. It's gaining an understanding of how a fish works, observing their behavior, how a fish reacts to their surroundings and what they can do to get shut down fish to bite. Adapting lures to produce more flash, more vibration, a wider sway, a tighter sway, slower/faster retrieve.

Thanks Douglas for bringing this up again, we need to be reminded every now and again that it's not just about throwing a line in the water and hoping, it's about how we can better understand a fish's behaviour and catch more fish.

There are many and varied uses a fish has for the lateral line and I don't think anyone can fully understand it all, but I do believe that in regards to a fish's behaviour, vibration and water pressure has a lot to do with it.

[Ducksta]

Betts spins for smaller species have been around and catching fish forever. Bigger ones are available in alternate brands, too.
Fishing a betts spin on a polycarb vibe lure was popular in bass comps when I was around them - so that was a good while ago.
More recently jigheads with the blades built on (rev-heads, underspins, whatever your preferred brand likes to call them) have been dominating.

My concern with your rigging Douglas is that a fish hits the blade and the leader is compromised.
This can be before the main strike, or while you're fighting a fish and that little blade looks like an escaping bit of prey that someone else comes for a look at.
Any benefit I'm not seeing over opting for larger Betts type rigs?

[Ducksta]

In the same vein, I actually had a play recently with an umbrella rig for the first time.
(I intended to use it in Brazil but never got round to it.)
The way I rigged it was with 4 2.5" spoons - painted one side and chrome one side with the main/middle arm holding a Happy Rock paddle tail.
I'm not sure if anyone up North has really given them a big run on barra but rigged that way they look like they would be dynamite!

[Douglas]

Thanks for the tips. Ducksta.

In the experimental phase I only want to use simple tools. Hence the spinner blade on the leader. if I was mucking around trying to catch things with teeth, I would certainly think twice about attracting something to the spinner blade and leader.

However, neither barra nor king have teeth (but I'm aware that a barra can give a really nasty suck).

so I'm happy to play around with a spinner blade straight onto 80 lb leader.

Didn't know about the jigs you mentioned Ducksta but I've now had a look. My initial gut reaction is that the blade is too close to the lure but I'm happy to look at that again.

By Betts lures do you mean the ones that look like a small coathanger being dragged by the hook with a spinner blade on one side and a hook/lure on the other? If so, then I've caught barra on them here. But they are undergunned for me plus too bulky.

I've seen videos of the umbrella rigged set-ups. Look a bit like an electrofishing boat with the electrodes in the water?

I also have another innovation in mind with the spinner blade. I'm not convinced that its the flash of a spinner adds to the lure's visual attraction. I look at those things as 2 separate subjects.

Am aware about the atmospheric pressure changes being transferred through the water column and the effect that apparently has on fish behaviour. Water can't be compressed so any pressure changes are simply transferred though the water to act on the fish's body. A ever-so-slowly changing pressure.

I'm simply talking about the extra pressure variations caused by movement within the water column and superimposed on the constant or slowly changing pressure from the atmosphere.

If the fish can detect relatively slow changing atmospheric pressure, that means that it has a response to low frequency changes.

That means its response curve is better at low frequencies than high frequencies. That means that the high pitched rattle of 2 steel balls is getting beyond the range of their lateral line frequency response curve.

Probably sounds a bit goobledygook but they're some of the conclusions I'm coming to.

So my experimenting is to do with producing pressure variations that fall within the fish's pressure frequency response curve.

A spinner blade produces lower frequency vibrations and I happen to have some handy. So that's what I've used.

In respect of colors we're talking about fish that operate within mainly dirty water which results in low light environment.

As you know different colours fade at different depths in clear water as the light diminishes. But in dirty water they fade much faster to the stage that they all fade out in the extremely low light environment of 1m or so of our good old muddy Fitzroy water.

That being the case, it stands to reason that barramundi don't have much in way of colour detectors in their eyes, Cones.

To make up for that they have more grey scale detectors. Rods).

So barra see mainly in grey scales unless they're in extremely clear water when there is more light level and then a limited colour ability is available. Maybe some really clear impoundments offer more light.

Somebody has suggested that its not so much the colour of the lures but more the contrast between grey scales that the differing colours represent in low light conditions.

Bit like an eyechart that only has varying shades of grey to pick from.

The surest way to attract your attention is the rapidly flick from darker grey to lighter grey. Similarly with barra. If the top of the lure is dark grey and bottom half is light grey, then a decent body roll with produce that venetian blind opening and closing effect.

I'm exhausted.

I'm probably not right in any of my conclusions but I'm determined to test them out.

At the same time I hope that it causes some of you guys to think a bit.


I've got a way to go yet.

[Ducksta]

Hey I was just referring to "Betts style" spinners in the same sense that people call vacuums, hoovers.
The actual Betts branded ones would be much too small - but others around have made bigger ones. The last ones I bought were from a BassPro shop in the USA.
Just showing the idea of the detachable arm that has a spinner blade on one end and a clip for your lure on the other.
Umbrella rigs certainly look unwieldy - and I definitely don't think I'd ever load them up with hooks on all the prongs - but nothing else I've seen looks/moves like a school of bait like they do.

[Douglas]

I guess that the above gives a window into why I'm thinking the way that I am.

Must be a hang-on from my old legal/engineering days where I feel that I have to prove things to an acceptable level.

I didn't know if Bretts was a particular brand or a generic term. Shows my naïvety to the industry jargon, I guess. I'm just a simple country lad who doesn't know enough to even ask the right questions.

Meanwhile, I've moved on a bit and am into hardbody lures.

Now THAT'S an interesting subject.

Anybody got any views on what I've rambled on about so far?

[Douglas]

Here's the result of the recent barramundi spawning at the mouth of the Fitzroy.

90mm and this little fella is about 1 month old and has travelled about 60km up river under his own steam.

There'll be thousands more of these and their survival will depend upon some timely followup flow in the river to enable these little guys to escape predation in the river by getting up into the safety of the floodplain lagoons.

DSC_0274.jpg