I'd agree on that alanmin, as with most things that humans muck around with,
what they started with is a design for a purpose that didn't need mucking around with.
The long finned oscars is a classic example, as is the colour morphs of the dwarf gourami,
all the shades, almost, of the rainbow, but now, compared with the "naturals",
are very poor at breeding and are so delicate,
you only need to sneeze in the same room as them and they'll get whitespot or dropsy, etc
Alan 104