Sexing Butterflyfish, or BGK

[KribFreak]

How can u tell what gender an African Butterflyfish or Black Ghost Knifefish, pictures would be best.

 

[Eelzor]

BGK's are impossible to tell the gender, but I am not sure on butterflyfish.

 

[beblondie]

butterfly fish sexing the anal fin is different shaped one is straight and the other is slightly concave-Anne

 

[bryce2003]

KribFreak,
It is far from impossible to sex BGK's. However it is quite hard as the differences in what I will explain takes a fair amount of observation and the right angle to see them from. It also helps if you have 1 of either sex when you first give it a go. The way to tell is as such. The male has a horses shaped head with his eyes being near the top of his head and set back from his mouth. The female has a more slender shaped head and the eyes are lower and closer to the mouth. There is another way that I am trying to confirm but haven't been able to test on enough fish to come close to what I would consider to be a definate way as of yet. That is from my observation I have noticed that most males have black eyes as the females do, but the females seem to have eyes that are black but more opaque. The other thing to be aware of is that it is way more easier to notice the above on larger fish than what it is with smaller fish. Hope this helps.
CHeers,
Bryce.

 

[ryan]

There are supposed to be some ways of sexing African Butterfly fish, but I can say that none of these give you a certain answer of male and female IME. Breeding is difficult but possible, the key appears to be very soft acidic water, peat filtration and RO water are recomended. The eggs which are lighter than water will float and can be collected with a tablespoon to be transfered to a hatching tank. The eggs should hatch within 36 hours but the fry are very difficult to raise as they will only take tiny live foods.

 

[Eelzor]

It is far from impossible to sex BGK's.

I stick to my statement - BGK's are impossible to tell the gender from male and female! - Physically.

Bryce - You seem to have developed your own method of sexing bgk's so it may not be right.

 

[Doggfather]

i agree with Eel.

I have never read your meathod of sexing anywhere, or any other meathod about how to sex these fish.

 

[bryce2003]

Fellas, you'd be interested to know that here in Queensland, Australia there is no less than 10 breeders of BGK's. 1 of which has about 8 breeding pairs. It was from actual breeders both past and present that I was first of all told, then shown how to sex them. When I was actually shown how to do it I was shown breeding pairs and it took a bit of time to be able to pick up exactly what to look for and how to do it but it is DEFINATELY POSSIBLE. Point to note is that these fish were 30-35cm and it was hard enough with fish that were that size to sex, what size fish are you trying to start out sexing with? Just because you haven't read it doesn't mean it's not true, as a lot of information still isn't known about these fish or is just plain wrong, as is the case with a well known "fact" that has appeared in numerous sites about BGK's and how they don't eat flake. They do, as I'm sure you and a lot of others are aware of but is still information that is offered by others. Since having learnt how to sex them I have taken every opportunity to sex every one I have come across and it is getting easier the more I do it, however it still takes time and I know of at least 1 person who can basically sex on sight with no dramas and no second looks. So try and get in the good books with a breeder and maybe they will show you first hand, if not with the information I have given you it should be a skill that is achievable, otherwise your on your own. Hope this helps.
Cheers,
Bryce.

 

[Eelzor]

Hey!, don't get me wrong, I read my fish books and don't always believe what I see on the net, it's just that your bgk sexing method is something I have never heard of. If your method is true, then cool, KribFreak can try it then.

 

[BlueIce]

I still question that method of sexing bgk as well...
How exactly are you proving that your guesses at the sex are correct?

I need some pics of the bgk spawning in a tank to believe it's being done that often. I also need rock solid proof that this method of sexing works...

Just because you have bgk with dif shaped heads doesn't PROVE that you have sexed them correctly.

 

[bryce2003]

This method was picked up and has continued to be used by breeders through having seen the females deposit the eggs for the male to fertilise, therefore by them watching this process they have been able to distinguish the differences between the 2 sexes by observing them and applying it to the subtle differences in their appearance which is consistent from fish to fish. This info and the methods of breeding them etc. are usually for sale with the breeding pair that people sell. That is you not only buy the breeding stock but the info that goes along with it which drives up the price and few people are willing to spend the money or the time and effort required in order for this to happen, here you get it for free. I have been lucky as I have come across a few people who were willing to help me out in my endeavours with these fish as not many were. Therefore with this in mind I have no dramas with passing this info on to those who also have a keen interest in these fish. Choose to take it on board or take it with a grain of salt it's ultimately up to you. Some people are never satisfied with the help or info given to them from those who are willing or have been informed themselves and some are only willing to believe their own eyes and experiences, if that is the case well so be it. However there is always a few who choose to try/do/see for themselves the help or advice or whatever and are willing to give things a go and I wish those people all the success that fish keeping can bring.
Bryce.

 

[Vip]

When someone like bryce2003 has a passion for a fish this case being a bgk, he might just be right, think of it people there is guys out there who spend hours figureing out the sex of fish, bryce2003 seems like one of those. Maybe there is a way to find out there sex other than waiting for them to spawn. But like all of us bryce2003 we would like some pictures of where your claim comes from because i am very keen to see if there is a way of it.

Keep upo the work

 

[Vip]

Just wanted to add aswell, maybe none of us have ever seen a female, so maybe they are differnt looks because just remember that breeders want to keep the prices up and get top dollar for there fish, if there females out there and everyone had one do you think we would still be paying $25 for a 5cm fish? i think not.

 

[vantgE]

Okay have a related question, cichlids have also been noted for haveing small differences between the male and females of each species. Such as On a labidochromis caeruleus, I have read that males have a black pectoral fins and females, don't or have much less, also te face shape has also been used a male is suposed to have more of a bumb on his forhead although no real bump, while the female has a more slender, less bunched up shape, also females are said to be smaller than males although again not always true. In other species eggspots have been used to prove sex, although this is far from acurate it is often true, (semperfi has a great pinned article on eggspots in the African section)Even in Sexually dimorphic species, the coloration of the fish has also been proven to be less then fact as less dominat males may apear as females, while more dominant female will similarily show male coloration. The only true documented way to determine sex for a mbuna for once and for all removeing all doubt is too vent the fish. Which requires you to net it, pick it up and hold it upside down with the top fin between you fingers. The male will have vents slightly different than the female and this is proven and wildly accepted.
Is their no way to view the vents of a BGK, because similarily, and although I recognize the research brcye has done, the situation could unfortunately just be similar the situation of mbuna as I have explained, and I do not understand how a bgk would not have vents,
Have you looked into this bryce?

 

[bryce2003]

vantgE,
I must say that I have never looked into it nor thought about asking about it either. I will endeavour to find out though.
Cheers,
Bryce.