EV> I just noticed now that two of them have a large black 
 EV> spots on their tail-fin,
 EV> but the third has a faded black spot, and red flares 
 EV> along the upper and lower edges of the tail-fin.  Is 
 EV> this a sex-related marking, or has this fish been 
 EV> nipped, or is something wrong, or is this a different 
 EV> lookalike species that got mixed in with the gold 
 EV> tetras?
I don't know for sure, but it sounds like gender markings.
Robby
--- Maximus 3.01
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