population ancestry2021
Japan ornamental guppy mitochondrial sample
Authors: Ryusei Satou & Masamichi Nakajima
What the paper actually found: Researchers screened 16 wild populations and 14 ornamental strains using a 320-base-pair mtDNA D-loop region. Most sampled ornamental strains had the Hap1 haplotype associated with a West Trinidad source; one Endler's form had Hap4. Okinawa populations showed multiple haplotypes.
What it cannot prove: A short maternal mtDNA marker does not prove the originator of any Moscow, Grass, Full Red or Koi commercial line, nor establish a breeding cross, nuclear color allele or 2026 breeder identity.
Breeder verification action: Verify original dam and sire collection/source, dates, traceable tank IDs and separate maternal haplotype claims from nuclear pedigree claims.
Original article or abstract
breeding fitness2001
Genetic change and inbreeding depression in small closed lines
Authors: Takahito Shikano, Takashi Chiyokubo & Nobuhiko Taniguchi
What the paper actually found: A controlled study maintained three guppy lines of ten breeding fish each and followed allele-frequency changes over six generations. Estimated inbreeding coefficients rose and average salinity-tolerance indices declined to 82.5%, 71.7% and 67.6% of baseline in those study lines.
What it cannot prove: These experimental salinity-tolerance values are not a universal water-parameter recommendation, a prediction for every show guppy, or a reason to conduct stressful salt challenges on pet fish.
Breeder verification action: Record effective breeding census, parent overlap, survival and fertility by generation; seek verified outcross histories without promising a universal fixed diversity threshold.
Original article or abstract
growth and welfare1993
Dwarf phenotype in selected laboratory guppy stocks
Authors: Yoshihisa Fujio & Masamichi Nakajima
What the paper actually found: Fancy F and Standard S3 laboratory populations differed in size; dwarf offspring arose in some brother–sister F matings. The study suggested a single major-effect gene for dwarf growth in its test animals.
What it cannot prove: This does not establish that every commercial short-bodied or 'balloon' guppy shares that gene or that a dwarf phenotype is a desirable breed standard. The result is from specific lab populations.
Breeder verification action: Ask for growth records at fixed ages, deformity and survival rates, welfare screening and documented lineage; do not equate selection for color with health.
Original article or abstract
reproductive provenance2018
Female sperm storage changes certainty of guppy pedigree
Authors: Clelia Gasparini, Emma Daymond & Jonathan P. Evans
What the paper actually found: Female guppies can store sperm across successive reproductive cycles. Artificial insemination experiments found a strong advantage for freshly inseminated sperm when it competed with stored sperm; natural matings can show different patterns.
What it cannot prove: An adult female's later brood is not proof of parentage by the most recently observed male, and laboratory artificial-insemination bias is not a guaranteed paternity percentage in a breeder aquarium.
Breeder verification action: Use virgin females separated before sexual maturity or verified paternity, dated pairing and brood notes, and document all earlier possible male exposure.
Original article or abstract
breeder history methods2001
Long-term laboratory strains, drift and quantitative traits
Authors: Masamichi Nakajima & Nobuhiko Taniguchi
What the paper actually found: The review describes guppy laboratory strains derived from Japanese-local stock and maintained as closed colonies for five to 20 years, summarizing genetic drift, inbreeding, heterosis and quantitative traits.
What it cannot prove: A closed colony retained for many years is not a verified one-gene strain, an assurance against drift, or proof that similarly named marketed fish descend from that laboratory's fish.
Breeder verification action: Request dated source acquisition, generation and outcross records, mating identities, consistent phenotype measurements and explicit custodian permissions.
Original article or abstract
No matching studies.