View Full Version : Barra Strains

20-06-2003, 04:19 PM
Are there 2 different strains of Barra being stocked in Qld?And is 1 slower growing? Im curious why Lenthalls isnt producing the same results as Awonga.Thanks if you can help ne1. Matt Q

20-06-2003, 07:38 PM
To the best of my knowlege, there are 3 strains of barra being stocking in Qld. Southern, Northern & Gulf. Pretty much most of the barra in Lenthalls went over the wall after an initial trial stocking. I actually fished downstream of the dam & happily caught stacks of rat bass & barra that came from the dam.
The wowsers conveniently overlooked the AWOL barra & used the lack of them in the lake as an excuse to not stock them any more.
However, Lenthalls being a shallow dam, is prone to a sharp temp drop in the evenings (more than the much deeper & more constant water temps of lakes of Awoonga, Faust, Monduran, Tinaroo etc). Constant lower temps dont hurt barra IMHO (have seen barra feeding in 17 degree C water & living in 13 C), it's the sharp temp drops in a short period of time that can kill them real quick.
You also need to look at the food webs for comparative lakes to get an idea on growth rates etc and also look at stocknig densities. Awoonga has had a couple of million barra liberated into it.

Southern barra do appear to be slower growing than their northern cousins. Whether this is due to a shorter period of high water temps & therefore longer high intensity feeding season of the southern species loactions, I don't know.


21-06-2003, 06:11 AM
Water temp makes a significant difference to feeding patterns and therefore growth rates.

We at Mackay Area Fish Stocking Association recently ran an experiment in our hatchery. We placed barra fingerlings into our grow out tanks where the water temp was about 24 -25 degrees and then placed some into another tank which was heated and the temp was 27 - 28 degrees. The barra in the cooler tank would not feed consistently or with any "gusto". Those in the warmer tank would feed actively whenever food was available and were a more active fish. They grew at twice the rate of the cooler tank.

For larger fish the issue is that they will feed in cooler temps (the old story - if you don't eat, you don't #@$%, you die) however it is how much food is required. Fish in cooler waters are much less active and therefore require much less to keep them swimming.

In all the material I have read about the different strains of Barra (around Australia I think there are 7 or 8) I have not seen anything that would indicate that the different strains grow at different rates (only where they are living and therefore what the water temp is and what food sources are available).

Fitzys comments about the depth of the water and the changes to temp are very relevant. His comment regarding the shorter high intensity feeding period (eg shorter period of high water temps) hold true.

The water Temp in Teemburra Dam last summer was cool (due to the cool dry nights bought on by the lack of rain and humidity) when compared to the previous year and hence the catch rates were also down.

Hope some of this helps.


22-06-2003, 05:34 AM
Following on from Fitzy and DRJ. This is just a guess but with fish being water temperature dependant, I wouldn't be surprised to find that the higher the temperature the faster the metabolism/digestion. This makes sense, if its body is hotter the digestion is able to quickly and efficiently empty the gut. They would explain why they seem to want to eat more in warmer water.

I'm sure I've something similar on crocs/snakes/reptiles. One of the croc keepers at a SEQ wildlife park said its bad to overfeed them in winter in Sth Qld because they don't digest the food quickly over winter because of lower body temperature (something about food sitting around in the guts for a long time is bad for them). Thus they grow slower because they can't eat as much food as crocs in NQ (same crocs). There is something about snakes using warm to help digest the food rattling around in my brain too, something about the Tiger Snakes in Islands north of Tassie being pitch black because they heat up being black that helps them digest their food quicker which is good for their short mutton bird season that keeps the snakes going for a year.

25-06-2003, 04:47 AM
Does is also relate to the available food source. I know most of the dams mentioned have healthy populations of boney bream / redclaw etc. I know if i was a fish a slow moving redclaw takes much less energy to inhale than a crazy boney.

25-06-2003, 04:58 AM
If the water temp is very low it doesn't matter how much food is available they just won't feed any where near as much. It is as lordy has said, the metabolism rate is much slower. They are also not as active so do not need to feed as often as they use up less energy.

If the water temp was high and there was a lack of food supply then you would have an impact on growth rate.


25-06-2003, 04:26 PM
Have seen the growth rates from several barra lakes & they all have a hiatus in winter.
Although an available food source is necessary to get optimal growth rates.
In some of the bass lakes in SEQ, there are some that produce big bass in short time (eg Big W, Somerset, BP, Boondooma) & others that rarely if ever produce a big fish (eg Hinze, Maroon, Clarrie Hall, Toonumbah etc) . It's all about the food web in the said location. Is also handy to be familiar with the local food web to be better able to target the desirable predator species anywhere. Barra, bass, cod, sooties etc etc.