Sexing Fp. gardneri mamfensis "Faishang"

[chicknb]

Hi all, this is my first post on the Forum and would like to ask about my Faishang. I have two batches (2 week difference) that are about 6 and 4 weeks old and some of the fry are smaller and noticeable darker than the rest. They eat normally and otherwise look normally. I noticed that when they first hatched, a couple of them looked like belly sliders but I am not sure if they were only newly hatched and trying to get some air or they were really belly sliders. I feed them dry tubifex, baby brine shrimp, live tubifex and paste food (prepared with all sorts of comercial foods, dried daphnia, dried redworms, carrot, tuna fish, vitamins, omega 3, and gelatin). One of the batches (about 12 fry) live in a 2.5 gal with proper filtration and a couple of plants and snails. The rest (8 fry) are in a 2 gal unfiltered plastic tank also with plants and snails. I do water changes about every 3 or 4 days (approx. 25-35%).

I would appreciate any comments about the color differences and when would I be able to differenciate males and females.

Tony

[keehoe]

Hi Tony, welcome to the forum. There is a strong believe that generally fishes sex are not fix when they first born. Not until 2 - 3 weeks later i suppose.

Recently i did a hatch on Simp. Igneus which is suppose to be highly skew towards female. I separated them into 3 fry per small container and guess what. I turns out to have even male:female ratio. I was hoping to get Trio from all the individual container. The fry were together on the first week and 4th weeks onward. They were is separate small container on 2nd and 3rd week.

Some fishes when they are excited/ stressed will turn darker colour. Giant Travelly, dolphine fish, sail fish for example (but those are salt water big fish)

Hope that helps.

[TyroneGenade]

There was an interesting piece in the Feb 2005 FAMA on sex ratios in the Betta column.

It was found that mating young males to old females produced many more males than females; and mating old males to young females produced the inverse. The best sex ratios were had in mating even sized fish.

So, what I am proposing is an experiment with our favourite fish: Fp. gardneri/nigerianus. If we can all put aside three tanks for the experiment we may be able to amass enough data to put this issue to bed. We need to setup a young small male with an old female, and in another tank the inverse. And then one more tank with a matched size pr. I will try my level best to get hold of some GAR to do the experiment on my side.

If we can get enough data from lots of different sources with different water conditions, and still show a trend in sex ratio determination as seen in Betta's that will say a great deal (and make for many more questions). If it doesn't work, well then we have advanced the frontiers of knowledge by exposing a crack-pot idea. In the mean time, lets perhaps focus on the science, that is asking the question and trying to test the knowledge we may perhaps have.

tt

[Gloup-Gloup]

Hi every body
What is a olds nigerianus for you...... 1 years, 2 years or more
I ask you that because I am interested to try this experimentation and I got several couple of Gard lafia gold but they are all 1 1/2 years old only

If I can't do this experiment I will follow your's for sure....

Your killie friend

Marc Pominville
"Gloup-Gloup"
Montreal, Quebec
Canada

[chicknb]

Hi all, thanks for your replies. I know there are different factors that apparently affect the sex ratio in different killies (for example, I obtained all males when hatching Austrolebias alexandri) but my question relates more to the visual differences between young Faishang. I still can not see any color developing on the fry so if there are apparent differences in the form of the fins at this stage or something like that. I have seen that some of the fry have a clear (white?) eye ring while other lack such ring and their eye look all dark. Also, I mentioned that some of the fry are darker and I mean darker all the time, not just some times.

Well, thanks again, if someone has any advice about this I would really apreciate it. Also, if there are some new results about what Tyrone suggested it would be interesting to know them.

Regards,

Tony