Unfortunately, yes because some high end guppies are delicate and seemingly less robust as their wild cousins but that would depend on it's genes too. I find short tail fancy guppies easier to keep and breed and much livelier, not so much for the heavy delta tails. If you want to breed fancy guppies, I suggest you look for the short/sword tails. Guppy galaxy or Guppy center should have these strains. Quite unlikely for local private breeders who prefer the deltas.
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