Re: Sex change in Apistos???

[Mike & Diane Wise <apistowise@bewellnet.com>]

For such sex changes to be valid, the original female has to have laid 
eggs & produced viable fry. Then she must change into a male & fertilize 
the eggs of another female & produce viable fry. These spawn need to 
occur in a  tank in which there are no other apistos. Koslowski (1985) 
reported that he had an isolated pair of A. sp. 
Wangenflecken/Cheek-spots breed for him several times. Once the male was 
removed the female developed masculine traits. Once this fish was put 
together with another female, they spawned & produced viable fry. This 
sex reversal may be more common than we realize. One that really 
surprised me was a report by Ginny Eckstein who reported that she had a 
breeding pair of Caquetia myersi. When she removed the male, leaving 
only the female in the tank, the female laid eggs several weeks later 
that produced viable fry! Her article was called "A breeding pair of 
one". Cichlids certainly can be fascinating in many ways.

Mike Wise

Nuno Prazeres wrote:

> Hi All,
>
> somebody just shared with me the following:
>
> after a few unsuccesful spawns of a A. cacatuoides couple (the fry was always eaten by cory cats) the male died. Sooner afterwards the female start growing and getting more colourful until a stage in which she looked just like her former mate.
>
> Now, a new trio was just introduced in the tank and the new male just dominated the goup including the original fish. Giving behavioural issues we can get to the conclusion the original fish seemed to have turned into a sexual active male.
>
> I suggested to take out the dominant fish to see if it would be possible to get a viable fertilized spawn from a coulple whose male was a spawning female a few months ago. That would be something!
>
> Anyone had such an odd experience?
>
> I read something like this about Dicrossus filamentosus and know apisto's sex is indeed influenced to a certain extent by external factors but thought that when the fish's sex is determined it would be for life. The external influence would be acting to drive the fish from a unsexed situation to a sexed one and that would be it.
>
> What are the factors that might cause a fish's body to "decide" to change sex? If this case is indeed such a thing I would say social or ecological factors would apply just like what happens in the case of the D. filamentosus.
>
> Take care all
>
> Nuno Prazeres
> (Portugal)
>
>
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