Re: Re: NANFA-- Sex change in Xiphophorus sp.?

John Bongiovanni (bongi_at_cox-internet.com)
Thu, 8 Jan 2004 12:19:15 -0600

It depends on which fish you are speaking about. Wrasses are sexually indeterminant, remaining as juvinile fish, until the alpha or beta male and female "slot" is open. I did a lot of research in the sex determinism in the early 90's and I seem to remember that live bearers are predetermined at birth. Carl Hubbs did alot of genetics work with the livebearers. In the wild state the sex determination was found on the chromosomes. I believe, and I know somewone will correct me if I'm wrong, the XX condition in Platies or swords was a male. Inbreeding caused all sorts of problems in sex determinism and so when you talk about the fish found in the aquarium trade you don't what you are getting genetically.

john

>
> From: EELReprah_at_aol.com
> Date: 2004/01/08 Thu PM 12:05:15 CST
> To: nanfa_at_aquaria.net
> Subject: Re: NANFA-- Sex change in Xiphophorus sp.?
>
> My understanding is that fish are not sex differentiated until several weeks
> or months after hatching and then they can be influenced by environment,
> including the sex of companion fry.
>
> Lee Harper
> Media, PA
> /"Unless stated otherwise, comments made on this list do not necessarily
> / reflect the beliefs or goals of the North American Native Fishes
> / Association"
> / This is the discussion list of the North American Native Fishes Association
> / nanfa_at_aquaria.net. To subscribe, unsubscribe, or get help, send the word
> / subscribe, unsubscribe, or help in the body (not subject) of an email to
> / nanfa-request_at_aquaria.net. For a digest version, send the command to
> / nanfa-digest-request_at_aquaria.net instead.
> / For more information about NANFA, visit our web page, http://www.nanfa.org
/-----------------------------------------------------------------------------
/"Unless stated otherwise, comments made on this list do not necessarily
/ reflect the beliefs or goals of the North American Native Fishes
/ Association"
/ This is the discussion list of the North American Native Fishes Association
/ nanfa_at_aquaria.net. To subscribe, unsubscribe, or get help, send the word
/ subscribe, unsubscribe, or help in the body (not subject) of an email to
/ nanfa-request_at_aquaria.net. For a digest version, send the command to
/ nanfa-digest-request_at_aquaria.net instead.
/ For more information about NANFA, visit our web page, http://www.nanfa.org