sexing A. agassizii

[guppy*]

I recently aquired 6 A. agassizii juveniles and I'm wondering how do you distinguish male from females? The fish are about 3/4-1" long. Any help would be appreciated Thanks.

 

[Mike Wise]

At that size they are too young to sex with any confidence. Sometimes you can see a dusky band running through the center part of the tail on males.

 

[Z Man]

If you check the ventral fins of each fish, you might see some have black along the leading edge. Those WITHOUT the black are usually males and those WITH are surely females.

 

[Mike Wise]

Males as young as your fish usually will also have black leading edges on the ventral fins. Fish without dark edges will be males, but those with dark edges - at the size that you have - could be either male or female.

 

[guppy*]

What are some signs to look for when they start growing into males and females? I know the color of the females are usually yellowish. Most of mine all have the black tip on the first ventral fin what does this mean? Thanks.

 

[cootwarm]

Hi Guppy,

I believe the only way to be certain, other than the way Mike Wise described, is to wait until they are sexually mature. The subordinate males often take on some female colors (black on ventral fins) to avoid harassment from the dominant male.

Sometimes you can pick out females where the black is very distinctive. Also if you can identify a male for certain, you may be able to pick out females by observing the way they interact with the known male. Subordinate males would most likely try to avoid the dominant male, where females becoming sexually mature might show interest in the male. But even then you can't be 100% certain until the females are ready to spawn and take on the bright yellow colors.

I don't have any personal experience with aggassizi, but the bright yellow in the females vary in some species. I find that my females cacatuoides are only yellow when they are ready to spawn and while taking care of the eggs. The ventral fins become especially contrasty. But once the fry are free swimming, their colors fade to a more normal brightness.

On the other hand, as long as there is a male present, my female "Maulbruter" have their bright yellow colors almost constantly once they become sexually mature. They are yellow when courting, when caring for the eggs and while caring for the fry. Once the fry are only 3 or 4 weeks old, she is ready to spawn again. So for them, it seems that the mating cycle never ends! I think female "Maulbruter" are one of the most attractive apistogramma females. Their colors are usually very bright and contrasty.

Michael

 

[guppy*]

Okay, its about 2 months later...I still have all six of them and it looks like they've only gotten a little bigger... :? I know there is one male I think. What are way to tell them apart. I have noticed that some or darkers than others but there are no physical differences on them. The one male has spade on his tail so is it a male? or am I wrong. When do they start growing more profolic fins?