Sex Ratio

[imported_n/a]

Hi all, IngMing here, trying to 'take advantage' of the 'open house' !! Great idea, good job guys!

Have heard talking about pH/temperature affecting male/female fries ratio, anyone has anything to share?

- Is pH/temp high/low produce more/less male/female?
(putting the age & factor of the parents aside)
- When does this temp/pH factors affect the sex of the fries
= Before hatch
= after hatch, and if so, how long?

thks,
IngMing

[Samuel Phan]

Hi Ing Ming,

Welcome ...

I have moved your posting to this new category. Also this topic have been discussed under the "General" category.

You can try to refer back to our old discussions for more info ...

I have heard of the PH effects on the sex ratio of the spawn.
I was told that excessive use of ketapang will cause the spawns to have higher % of females ... but this has yet to be confirmed.

This is a topic that requires some in-depth understanding which I will reserve to pple like Dr Hsu or Foo Hong to elaborate.

With Best Regards,
Samuel Phan

quote:
Hi all, IngMing here, trying to 'take advantage' of the 'open house' !! Great idea, good job guys!

Have heard talking about pH/temperature affecting male/female fries ratio, anyone has anything to share?

- Is pH/temp high/low produce more/less male/female?
(putting the age & factor of the parents aside)
- When does this temp/pH factors affect the sex of the fries
= Before hatch
= after hatch, and if so, how long?

thks,
IngMing






Samuel Phan **** Chiat
(Creator Of Sam's Betta Colour Rendezvous)

[imported_n/a]

Haha, so you are the mouse who move my cheese !!
No wonder I come back search high and low, and couuld not find my posting again...'am I screwing up the whole forum'or what?? haha'...sorry that you need to do this clean-up & thks.

Hope to see if anyone has any further insights to this topic

rgds,
IngMIng

[Samuel Phan]

Hey ... no problem ... this is the job of the administrator and moderators.

And how come you know I am a mouse??? (born in the year of rat)

As for more insights ... please feel free to look around.

With Best Regards,
Samuel Phan

quote:
Haha, so you are the mouse who move my cheese !!
No wonder I come back search high and low, and couuld not find my posting again...'am I screwing up the whole forum'or what?? haha'...sorry that you need to do this clean-up & thks.

Hope to see if anyone has any further insights to this topic

rgds,
IngMIng





Samuel Phan **** Chiat
(Creator Of Sam's Betta Colour Rendezvous)

[Chris Yew]

Hi IngMing,

Welcome here! Since you're the 1st non-member making a post here, you'll get a present from me;

In humans, sex determination is by the chromosomes. A woman has two X chromosomes, while a man has an X and a Y. As such, the mother always contributes an X to each offspring, while the father has a 50% chance of contributing an X and a 50% chance of contributing a Y. The sex of each offspring is entirely determined by which chromosome the father contributes.

Fish do things differently, and as befits the diversity of fishes, there is diversity in how sex is determined. If you were to peek inside the cell of a fish; the sex chromosomes usually look the same. While in some fishes there appears to be chromosomal inheritance of sex, often sex determination is more flexible, influenced by environmental factors such as temperature, pH, hormones, and social conditions. Even in cases where there is chromosomal inheritance of sex, extreme treatments can "override" the genetic basis of sex. For example, genetically female guppies will mature as males if raised in extreme temperatures (Francis, 1992). Recent work on cichlids is revealing the extent of this flexibility.

David Rubin (1985) of Clark University followed up on Heiligenberg's (1965) observations that sex ratio in broods of Pelvicachromis ("kribensis" and relatives) seemed to vary with pH. Rubin bred pairs of P. pulcher, P. taeniatus, and P. subocellatus and raised the offspring at various pH levels. He determined their sex around 180 days after hatching either by dissection or by external observations. The results agreed with Heiligenberg;

Acid water tended to produce more males and basic water gave more females. For example, at a pH of 5.0, 96% of a P. pulcher brood became males, while at a pH of 6.9, only 20% became males.

Very recently, Uwe Romer and W. Beisenherz (1966) examined sex determination in 37 species of Apistogramma. They created pH treatments of 4.5, 5.5, and 6.5, and temperature treatments of 23, 26, and 29

[Foo Hong]

Aiiiiyyyeee..
I ve also posted a thread..same topic....
sam phan, can we 'merge' the 2 into 1?

[Samuel Phan]

I think cannot ...
Maybe Chris can help duplicate his posting to your thread.

quote:
Aiiiiyyyeee..
I ve also posted a thread..same topic....
sam phan, can we 'merge' the 2 into 1?


Samuel Phan **** Chiat
(Creator Of Sam's Betta Colour Rendezvous)

[Myron Tay]

Interesting view from Mr Sim Hup Kooi on the malaysianbettaclub Yahoo Forum:

From: "Sim Hup Kooi" <simhk@s...>
Date: Tue Sep 2, 2003 12:23 pm
Subject: Re: [Malaysian Betta Club ] Re: how do I get more male bettas from breeding?

males, easily 70%.

----- Original Message -----
From: "myrontay" <myron@s...>
To: <malaysianbettaclub@yahoogroups.com>
Sent: Tuesday, September 02, 2003 11:14 AM
Subject: [Malaysian Betta Club ] Re: how do I get more male bettas from
breeding?


So the better conditioned male produces more males or females?

--- In malaysianbettaclub@yahoogroups.com, "Sim Hup Kooi"
> <simhk@s...> wrote:
> > The 2 factors temperature and ph are statistically confounded because ph
> > will change with any change in water temperature, to be sure which is the
> > significant factor, some method must be devised to hold one factor constant
> > before a statistically correct experiment can be done. My own experiment
> > seems to point to the condition the male fish is kept in prior to breeding,
> > the breeding tank condition does not contribute significantly.

[Myron Tay]

Interesting view from Mr Sim Hup Kooi on the malaysianbettaclub Yahoo Forum:

From: "Sim Hup Kooi" <simhk@s...>
Date: Tue Sep 2, 2003 12:23 pm
Subject: Re: [Malaysian Betta Club ] Re: how do I get more male bettas from breeding?

males, easily 70%.

----- Original Message -----
From: "myrontay" <myron@s...>
To: <malaysianbettaclub@yahoogroups.com>
Sent: Tuesday, September 02, 2003 11:14 AM
Subject: [Malaysian Betta Club ] Re: how do I get more male bettas from
breeding?


So the better conditioned male produces more males or females?

--- In malaysianbettaclub@yahoogroups.com, "Sim Hup Kooi"
> <simhk@s...> wrote:
> > The 2 factors temperature and ph are statistically confounded because ph
> > will change with any change in water temperature, to be sure which is the
> > significant factor, some method must be devised to hold one factor constant
> > before a statistically correct experiment can be done. My own experiment
> > seems to point to the condition the male fish is kept in prior to breeding,
> > the breeding tank condition does not contribute significantly.

[Adrienne Kang]

As posted in a similar topic under Genetics section
(see http://www.bettaclub.org.sg/forum/topic.asp?TOPIC_ID=1496)

"There are no unequal chromosomes in bettas that might be sex chromosomes. However bettas seem to follow the XX, XY model since they normally produce 50% of each sex. Bettas can produce surprises. If young males are bred with old females, the resulting offspring are mostly males. If the fry are held at abnormal conditions during the first 6 weeks an overwhelming % of males is again produced. And of females are partially ovariectomized (most of their ovaries cut away), they transform into fully functional males" (Lucas 1983)

In Dr Lucas' doctoral dissertation (1968), he gave some general observations concerning sex determination.

1. Sex ratio extremely and significantly variable.

2. Consistent advantage to the male sex which remains unexplained.

3. Differential mortality does not appear to be a factor in the production of abnormal sex ratios

4. Rearing of spawns in constant temperature ranges +/- 2F of 80 F optimum did not influence the obtained sex ratios.

5. "Water conditions" appear to cause different ratios, possibly through some constituent not yet recognised.

6. Mating combination involving parents' age variations can produce abnormal sex ratios.

7. There is some evidence that a young male, older female combination may result in a higher male percentage.

The above is an extract. New observations are probably made since 1968.
For everyone's reference.

[ag]

[Adrienne Kang]

As posted in a similar topic under Genetics section
(see http://www.bettaclub.org.sg/forum/topic.asp?TOPIC_ID=1496)

"There are no unequal chromosomes in bettas that might be sex chromosomes. However bettas seem to follow the XX, XY model since they normally produce 50% of each sex. Bettas can produce surprises. If young males are bred with old females, the resulting offspring are mostly males. If the fry are held at abnormal conditions during the first 6 weeks an overwhelming % of males is again produced. And of females are partially ovariectomized (most of their ovaries cut away), they transform into fully functional males" (Lucas 1983)

In Dr Lucas' doctoral dissertation (1968), he gave some general observations concerning sex determination.

1. Sex ratio extremely and significantly variable.

2. Consistent advantage to the male sex which remains unexplained.

3. Differential mortality does not appear to be a factor in the production of abnormal sex ratios

4. Rearing of spawns in constant temperature ranges +/- 2F of 80 F optimum did not influence the obtained sex ratios.

5. "Water conditions" appear to cause different ratios, possibly through some constituent not yet recognised.

6. Mating combination involving parents' age variations can produce abnormal sex ratios.

7. There is some evidence that a young male, older female combination may result in a higher male percentage.

The above is an extract. New observations are probably made since 1968.
For everyone's reference.

[ag]

[Phil]

Here is my 2 cents contribution. On the practical point of view, I have noted that young males when mated to older females tend to result in higher infertilility. This is generally, because the young male usually have a problem of wrapping itself round an older female and as a result a lot more eggs are unfertilized. In Indonesia the common practice is to use an older male to a young female. The matingf is just done once and the female discarded after the mating. The results are usually approx 70% males and 30% female ratio. However, an important point to note is that Indonesian water is slightly on the hard side and of course temperature consistent to that of Singapore.

[Myron Tay]

According to the Feb 04 Livebearer column by Dr Ted Coletti, livebearer spawns' sex ratios may be affected by the following factors:

(i) Genetics - Inbreeding a particular race of fish often results in consistently biased sex ratios. So try to introduce new blood into your colony for better sex ratios.

(ii) Maturity - Early maturing male X. helleris (which tend to be smaller) sired significantly more male offspring. Late-maturing, larger males sired more females.

(iii) Water Chemistry - The effect of pH has been noted repeatedly in egg-laying fish such as Killies, Kribs and Apistos. There is little evidence, however, that pH has an effect on the sex determination of livebearing fish.

(iv) Temperature - Among livebearers, higher temperatures have skewed the sex ratios of Guppies and Poeciliopsis lucida to the male spectrum. UK hobbyists have observed that Limia nigrofasiatum skews female at higher temperatures.

[Lyon Goh]

Here's a phrase on the write up on Betta Smaragdina by Yohan Fernando and I thought since its closely related to Splendens, why not post it?

"There was no difference in spawn size of growth rate, which makes me conclude that this species, like its closely related cousin, the B. splendens is very adaptable to its environment. However, I did notice a difference in sex ratio. The fish that spawned in hard, alkaline water yielded a higher percentage of males."

[Myron Tay]

quote:Originally posted by Wayne

I have heard somewhere that it is possible to control the percentage of male and female in a spawn. But I have forgot where I saw that.

Did anyone of you know or seen any article like this?
Wayne

Can you find what you are looking for on this thread?

[Wayne]

Hi Myron, so my post has came here. :D Was searching high and low like IngMing.[B)]
Just an idea, may be next time you want to move a tread, you might want to rename the tread title a bit and inside the tread, edit the post to show the tread you would like the new question to redirected to? Sorry, don't mean to increase your work load. Just an idea anyway. [:I]

Hmm, no definate answer thought, but get a few comman point: ph and temperature. Some experience breeder from Penang has been telling me it is because of some hormones. He never tell me what hormaones though.so i though i will get the answer here since so many expert is here. :D

[Alex Lim]

Wayne,

i second your first paragraph.. it would be best and polite to send a PM to the original creator of the thread so that he knows where to locate it and not as mentioned, searched high and low for it to no avail. just a remark.. :D

thanks

[Myron Tay]

Oh, I thought that it should show up once you click under "Active Topics"? Let me know if my suggestion would suffice.

[Alex Lim]

Wayne,

i recall reading an article by Leo Buss (pardon me if i make a mistake in the name) between jarring the males and leaving them in community tank, on the effect of finnage.

one of the findings of the study reveal that when jarred, the male bettas tend to release greater qualities of male hormones and less of female hormones, resulting in longer finnages. in the community tank, most males do not release massive qualities of these male hormones and have generally shorter finnages. this applies across the board except for the dominant male in the community tank, which displayed similar traits as the jarred fellas.

applying this, could the permament gender of the fellas be influenced by the amount of such hormones released, as you mentioned earlier? i.e bettas remain relatively unsexed till the greater amount of whichever hormones caused them to be tilted towards a certain gender. i'm not sure of the effects of water change on the forming of betta gender, since the dominant hormones could be diluted.. [cnf]

if indeed so, the theory that bettas are sexed from birth (genetics) may not be wholly accurate afterall. the influence of other factors cannot be discounted.

please take my assumptions with a pinch of salt because i've been a genetic nutto [bt]

for discussions please.

Myron,

i believe it is only polite to inform the creator of the thread of the change. few months ago, there was still this feature but recently, it has appear to diminish or has been abolished, in my experience. not sure if this applies only to certain people. [:o)]

[Wayne]

Myron, is it? Hmm.....never try the active topic though, let me try later. :D

Alex, i saw a post from a member here call sunnychai who mention that they use a solution to get more male out of a spawn. I am amaze no one is curios enough to check with him what that *solution* is. [be]
Yes, i think someone has already confirm (i might be wrong) that fry are not geneticly sexed. Some breeder from US has told me that they have got most male out of a spawn when their temperature is 87-88F.

I really hope sunnychai will tell us how this works?

Oh ya, if am not mistaken, there is a question left unanswer, that is, when will a fry start showing its gender? I guess again this is a question hard to answer, because I have seen 3-4months old fry as small as fry that's < 1 months old. It depends.

[paul kusmin]

hmm, i don't think sunnychai will tell us how it works (i tried to pry the info out of him on another forum already). suffice to say, this topic is of great interest to me and i have seriously considered taking sunnychai up on his offer, shipping costs to canada are the only hinderance as he assures me that the effects of his solution will not harm the fish in any way and really works. i have asked this question of male to female ratio on a thai forum and if i dig up info different to what has already been posted here i will submit it...

[Myron Tay]

Thanks, Paul. Do let us know about your findings.

[Myron Tay]

Great discussion on this topic:

http://www.famamagazine.com/e/env/0001RDn0VGFl9f0U8I541A6/secure/login.html?link=/framepagesecure.html&item=jan2005:f-cl-bet-012005-1

User ID: guest
Password: guest

Conclusion: While Gene's data on the plasticity of sex ratio in Betta spawns is that which evolutionary theory would predict, that fact does not preclude other factors as modifying sex ratio as well. Issues of sufficiency aside, there are clear lessons here for both the commercial breeder and hobbyist. If you are a commercial breeder, you may expect a higher frequency of the more marketable males by mating young males to older females. And hobbyists, who are seeking to continue to develop or maintain a line, should be careful in their use of backcrosses. Backcrosses of mother to son are likely to leave you with few females with which to work and those from father to daughter, few males. Evolutionary first principles suggest that breeders make both backcrosses or make the brother-to-sister cross to best ensure themselves of having a choice of breeders of both sexes for the next generation.

[Myron Tay]

quote:Originally posted by dangthuy


Hi every body,
I'm new to this forum. I'm breeding betta in Vietnam. I usually get over 70% female each spawn. I wonder if you woud helf to have mre males.
Many thanks,
dangthuy.
Hi Dang Thuy

This mystery has been solved. To get a balanced ratio (50% males, 50% females), use parents that are of the same age.

[simliangyi]

hey guys.. i have read in a mag that the ratio of sprawn will depend on the surrounding.. what i mean is that for example.. if the female/ male is surrounded by a lot of females..it will 'think' that it is lacking in male therefore it will sprawn more of the male and vice versa.. it is also v true that the age of the female will affect.. this is tested and proved...