Dusky Flathead

[Trapper Tom]

G'day Raiders.

I always love targeting these big buggers, awesomely satisfying to set up a specific area and tactics to succeed in that area. Had good succes this Jan. But I always try to seek an edge to gain that litle extra info to maybe increase options and chances.

So I sometimes trawl some of the scientific reports to try to glean that little edge, better understanding of the relevent target species.

Did the Dusky Flathead today.

WAIT FOR THIS BIT!!!!

Department of Primary Industrys report into sustainability of the Dusky Flathead, July 2008 Report No 101 fully funded scientific report.

It Sampled 7783 dusky flathead of varing sizes from estuaries up and down the coast of NSW during the recognized spawning period Sept - March.

Excerpt (and not taken out of context).

"Overian and Testicular tissue was never once observed together in the SAME gonad", that being of the sampled specimin group.

For those unitiated with the term or the processes, in laymens terms, it means:-

Dusky Flathead do not change sex and turn into females as they get larger.

They are either born Male or Female and remain that way for their life span.

Yes FR's unfortunately its a myth that all the bigger ones are the female breeders.

I was absolutely flabbergasted reading it. It does explain however why some of the bigger ones I have caught have been male, it was puzzling at the time but I put it down to maybe environmental inhibitors that prevented the sex change (as does happen with Barra).

Interesting to note though that the females for the same age of that of a male, were slightly bigger.

Hence that is where I think the myth has anecdotal substance ie its origin.

Also interesting and don't quote me, but I am sure the sample specimens were 75% male and 25% female and this would be normal for most fish species for obvious reasons.

That does dot necessarliy mean that you keep all the big ones, in fact you should not, I practice not just sustainabilty but a "Moral" approach to fishing, and that is if you catch a large very long lived slower growing species (bream incl here) it is treated with respect always and goes back into the drink with the blessings of the fishing gods to live its life to its natural end.

I am now really interested to find out if there is ANY way to determine a larger male as opposed to female by suttle external physical examination.

Keep you all posted on this as it really is astounding. If any FR can tell the diff externally betweeen male and female please post as it would ensure a even higher release rate for the important bigger females.

Also on a side note saw some studies on mortality catch and release rates.

Those sampled a couple of the fishing tournos. Findings were 10% mortality and surprisingly attributed to poor water quality in the holding tank and the use of notted landing nets and not the enviro ones.

Hey fishraiders this is only one scientific report looked at so if anyone has accessed another that debunks this please post to assist other FR's.

Oh and great info for myself and others trying to crack the 1m flatty mark. "Kailola 1993" reported and confirmed a 1.2 metre dusky.

Cheers Fr's

Trapper Tom

[Trapper Tom]

Hey Fishraiders.

Wow I thought this thread might have generated some significant debate and a HOO Bra Haa!!!

None the less, Played on the computer last night and I cannot come across any external markings etc that would differentiate a male flathead from a female one. Keeping in mind that the males by forming 75% of the population are in fact unimportant to the the continued propagation of the species and can be kept with no discernable impact, its the 25% of the big females that ARE important.

Have been mulling it over and have just thought of one common sense discernable aspect that could assist in ID.

In the breeding seeson with the males if you turn them upside down and apply a slight/soft pressure to the middle abdomen and then slide down towards the anal area it will visably produce Milt (sperm). Those ones you can happily keep. If not, its a female breeder and back into the drink she goes.

Also note that the same procedure will, if a females eggs are very ripe, cause those to be extruded and provide a positive ID there as well.

Yes and I know that the response from many catch and release people will be "If their big just let them go".

But in reality, the majority of fisherpersons are not a catch and release and they will keep their wonderfully large prized flathead that they worked so hard for and deserve to keep. If additional info can be provided so that they are aware of how to maybe ID a female they may just release that most important female.

Hey Mods/Stewy I Reackon this is a actual very important piece of info for the species and your site, it could assist all FR's in releasing a higher proportion of the breeding females and thereby doing our bit. A bit of support here if you are able would be appreciated, I also understand it if you cannot for all the obvious reasons.

And now I am going fishing!

Regards

Trapper Tom

[cut_loose]

That's an interesting read.

One thing i hate about when i hear people catching big Flatties is 'it was over a meter long etc' yet i have never seen one on a ruler that was over a meter, anyone got photo proof of a Flathead a meter or over on a ruler ?

[spaners]

Top stuff Trapper,great report.Im all into CPR fishing but I do take as well.

Its good to know now that I can take the large boys and it is doing the system some good.

One question,,how many fish would a large flattie eat every day? Lets say one large boy eats half a dozen Yakka size fish per day,thats 2190 fish taken out of a system every year by one fish..

In theory we should be taking more flatties as the result will be a healthier system.

Regards.

[Anti-Carp]

Hey Fishraiders.

Wow I thought this thread might have generated some significant debate and a HOO Bra Haa!!!

None the less, Played on the computer last night and I cannot come across any external markings etc that would differentiate a male flathead from a female one. Keeping in mind that the males by forming 75% of the population are in fact unimportant to the the continued propagation of the species and can be kept with no discernable impact, its the 25% of the big females that ARE important.

Have been mulling it over and have just thought of one common sense discernable aspect that could assist in ID.

In the breeding seeson with the males if you turn them upside down and apply a slight/soft pressure to the middle abdomen and then slide down towards the anal area it will visably produce Milt (sperm). Those ones you can happily keep. If not, its a female breeder and back into the drink she goes.

Also note that the same procedure will, if a females eggs are very ripe, cause those to be extruded and provide a positive ID there as well.

Yes and I know that the response from many catch and release people will be "If their big just let them go".

But in reality, the majority of fisherpersons are not a catch and release and they will keep their wonderfully large prized flathead that they worked so hard for and deserve to keep. If additional info can be provided so that they are aware of how to maybe ID a female they may just release that most important female.

Hey Mods/Stewy I Reackon this is a actual very important piece of info for the species and your site, it could assist all FR's in releasing a higher proportion of the breeding females and thereby doing our bit. A bit of support here if you are able would be appreciated, I also understand it if you cannot for all the obvious reasons.

And now I am going fishing!

Regards

Trapper Tom

Thought provoking and a great post Trapper Tom !!

There's a lot of emotivity around large flathead and they ain't exactly rare if you know where to target them. The idea of large flathead being breeders is a myth. When it comes to fertility, it's a bell curve with an optimum age & size. Therefore fish younger or older than the peak will be less fertile.

People who advocate the "big breeder" myth need to look @ the facts DNA Decay's and you only have to walk to your local suburban mall and see who are the more fertile.

I would dare say it would be better for the flathead fishery overall to release or limit the mid-sized fish in the 45 to 60 cm bracket as they would be closer to this reproductive peak.

Generally I release the vast majority of my fish not because I appreciate and respect the fish.