Re: NANFA-- Elassoma

John Bongiovanni (bongi_at_cox-internet.com)
Thu, 06 Jun 2002 20:45:32 -0500

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After several generation of inbreeding with the livebearers, I think it
was Hubbs that noted the suppression of the
male chromosome after successive backcrosses with F1s resulting in all
female morphs. Something similar may be happening in reverse though; an
over expression of certain characteristics from the male chromosome.

johnB


R. W. Wolff wrote:

>I have had this happen on occassion, the skewed sex ratios that is.
>Killifish have been watched in this regard, and no concrete reason for this
>happening. Some is attributed to temps, pH, and many other things or a
>combination of things. No real reason has been set. One possibility in my
>opinion is these fish develop quite early, often fully colored up at less
>than a half inch. It is possible the males are atleast bullying the females
>and they waste away, or worse yet killing them. Elassoma are generally
>peaceful, but I have had locations where the males are relentless and loose
>many females to this. The bacteria could be secondary or unrelated to the
>problem of low number of females. If females are dieing out unnoticed they
>would add to the waste load in an aquarium as well.
>Ray
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/"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
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