Flathead fans a MUST READ!!!

[Jeremy87]

thx for the post.

how can u tell whether its a male female (without cutting them up)? I always put the big ones back thinking they are females.

Dan

I have a theory based on head shape, but thats for my honours project. If you run with the big ones are girls and the others go nicely with a bit of butter in the pan then it's enough for most.

Yeh Chris you've summed it up well. It's just an assumption alot of people have made and run with, though if you flick through the forums and magazines you'll find that there have been a few who have questioned the belief due to lack of evidence. I think starlo might be one. Clever bloke ,while he does all the usual fishing personality things he also seems to have a good scientific knowledge of alot of fish aswell. Anyway the next time someone says to me they swap sex over i'll be saying that the evidence suggests otherwise.

[jackson4300]

yea thats an eye opener, have had more people tell me they change sex then those who say they don't. Hes done his research and written it up in a good way for all to read and understand which shows that he actually does know a thing or too (as he should if hes doing a PHD)

Even though its not going to change or affect what we do as we already do realese the larger flatties which are females it is still something interesting to know.

[RayDeR]

G'day!

Just a thought: If we assumed that all "survivors" became females after a certain size, and were wrong in that assumption, do we need to work out a way to protect smaller females? That is, those in the 40 to 70cm range?

Ray De R

[Jeremy87]

G'day!

Just a thought: If we assumed that all "survivors" became females after a certain size, and were wrong in that assumption, do we need to work out a way to protect smaller females? That is, those in the 40 to 70cm range?

Ray De R

Not a bad point but if you look at it from the new perspective it also means that you know have a higher proportion of the population being females than previously assumed, while the big girls are the major contributors to recruitment you'd have to think the plain numbers of smaller specimens would have to also make a significant imput.

I suppose idealy you would try to limit the removal of females but unfortunatly atm the only way you can tell the difference between the 2 sexes in similar sized specimens is to open them up and have a look inside (possibly leading to higher release mortality rate ).

[Lovey80]

G'day!

Just a thought: If we assumed that all "survivors" became females after a certain size, and were wrong in that assumption, do we need to work out a way to protect smaller females? That is, those in the 40 to 70cm range?

Ray De R

I think Jeremy has a good answer to that one but I think we have it right as far as protection is concerned. These big girls must be doing something right. There is pleantly of Flatties around in most area's. While they aren't as prolific as bream I don't think they ever could be. The amount of times Iv'e thrown a cast net and caught reall small ones lets me know they are breeding fine. (Before the green brigade get on thier horses, the baby flatties go back before I worry about the live bait).

At the end of the day the flatty definitely has made a resurgance and am glad fisheries brought in the rules about the big flatties.

Cheers Chris

[RayDeR]

G'day!

If it takes a PhD candidate to tell us that flathead do not change sex, I was really wondering if anyone has really looked for sex differences in the physical appearance of flathead.

Jeremy alluded to head shape in a previous post.

Ray De R

[Jeremy87]

G'day!

If it takes a PhD candidate to tell us that flathead do not change sex, I was really wondering if anyone has really looked for sex differences in the physical appearance of flathead.

Jeremy alluded to head shape in a previous post.

Ray De R

Just a theory, not based on anything as yet. I just noticed out of personal experience that all the big girls have a characteristic round head, and yet in smaller specimens you get this squarer more even tapered head shape. I always assumed that this was a male female thing and when the mature their heads change into this rounder head shape. But since this thread was brought up it doesn't make sense and reflecting i can also recall smaller specimens with the rounder head shapes. It might be nothing but if it turns out to be females have a round head and males have a square head then just remember who came up with it.

anyway heres 2 photo's one is of a 45cm job i caught a couple of days ago and the other is of a 61cm fish that my mate caught a few years ago which sought of show what i'm going on about, please tell me you see it aswell and i'm not just going crazy.

[reidy]

Good day Jeremy87,
Good call about head shape.Do alot of off shore flattie fishing in Tas. and have noticed a similar trend,Smaller flatties on the Bell Bay mud flats (1000s of 100-250mm models) have the same rounded head shape as the larger (much larger) off shore critters.The exeption appears to be tigers who all have the narrower head.I do agree with the WA study that our flatties are not hermafradites (poor spelling David) as I have caught a number of large 700mm + models during the spawn that are def. males (they release their milk at the side off the boat).
A very interesting topic
Cheers
Reidy

[Lovey80]

Bump for those reading the other flatty thread.

[reel scream]

. The females and males of the Yellowtail Flathead attain a maximum length of 615mm and 374mm respectively.[/B]Cheers Chris

Thanks for the info Chris. Trawled off WA and would have to ?? those max lengths mate. Yellows out of 45mtrs go well over the 70.

Cheers Scott

[rando]

How many of you have filleted a maximum legal size male.Something to look out for when you are at the filleting table in future.

[Lovey80]

Scott, I think they were only refering to the estuary version of the fish. I'm guessing those figures were of ones caught inshore only. But going on those figures it would be safe again to assume that the ones offshore well over the 70cm mark are also females.

Cheers

Chris

[Lovey80]

bump again for another flatty sex change thread

[gr hilly]

yea and if we take all the males there will be nothing to bang the females and you know how stroppy a sheila gets when she gets nothing,hahaha
Hilly

[bondy99]

G'day Jeremy87,

Maybe run this via Ian Tibbetts back at CMS, it would be interesting to see if a project could be done on this but dont think anyone would be giving up a nice tasty flattie for science.

Off topic.

From what I gather from a researcher there appears to be two species of snapper on the coast. DNA is to be done but Fisheries are not keen.

The two species of snapper have slightly different morphometrics at the head and another section from what was said. I cant eloborate any further as that's all I Know of.

Happy fishing, Peter