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Named evidence gapHow do named aquarium colour lines segregate in F1, F2 and backcross generations?
A precise unanswered question is part of the source of truth. It prevents an absent study, indirect result or popular rule from becoming false certainty.
This is a current search boundary, not proof that no study exists. The dated searches below show what was checked, which candidates were included or excluded and what evidence would change the answer.
Current boundary
Molecular pigment studies do not provide inheritance ratios for trade lines, and seller charts are not pedigrees.
What would answer it
Source-separated, replicated crosses with parentage confidence, common scoring conditions and complete phenotype denominators.
Answerability brief
A coordinated community study may answer part of it
A prospective shared protocol across independent systems may answer a bounded field question if allocation, denominators, exclusions and analysis are fixed before outcomes are known.
Decision at stake: What offspring distributions can be expected from documented named-line crosses rather than seller-chart folklore.
Primary endpoint: Complete phenotype counts in F1, F2 and backcross generations under a fixed scoring method.
Minimum design: Source-separated replicated crosses with documented parents, contamination control, parentage confidence, common rearing and scoring conditions and complete offspring follow-up.
Required reporting: Scientific-name claim and identification basis, seller line and source, parent images and grades, cross direction, family and tank structure, mating uncertainty, all eggs, hatches, survivors and scored offspring, scoring method, exclusions and raw phenotype counts.
Community can contribute: Experienced breeders can run preregistered family-level crosses with complete records, including ordinary, unexpected and unmarketable offspring.
Community observations cannot establish: Trade names, selected showcase photos and survivor-only summaries cannot produce inheritance ratios or prove genetic purity.
Closure rule: A result closes only the exact documented cross and scoring method. Replication across independent source populations is required before a line-name generalization.
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Current research allocation
Design before asking people to participate
Method, units, exclusions, welfare boundaries and analysis must be frozen before inviting participation or viewing outcomes.
Why this allocation: Documented crosses could replace seller-chart folklore and create a distinctive community contribution, but incomplete showcase offspring would reinforce the same problem.
Next permitted unit: Freeze one exact line-pair, cross direction, family structure, contamination controls, image standard and complete F1 and F2 counting plan.
Activation trigger: At least two source-separated breeders can preserve all offspring denominators and agree to publish ordinary, unexpected and unmarketable outcomes.
Stop decision: Do not recruit when parent identity, family assignment, contamination control or complete offspring follow-up cannot be maintained.
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Reviewed: August 12, 2026.
Topics: Colour, Genetics, Breeding
Practical guides governed by this gap
Reproducible search trail
Do controlled pedigrees report F1, F2 and backcross ratios for named aquarium colour lines?
Taxon names: Neocaridina davidi, Neocaridina heteropoda, Neocaridina denticulata sinensis.
Concepts: colour morph cross, F1, F2, backcross, inheritance ratio, trade line.
Search surfaces: publisher and DOI records, scholarly web indexes, genetics journal indexes.
Outcome: The new crustacyanin study adds another functional molecular candidate, but its public record does not expose the complete units or report controlled named-line pedigrees. No study reporting complete F1, F2 and backcross phenotype denominators was located, so the inheritance gap remains open.
Exact queries and candidate decisions
Exact queries
"Neocaridina davidi" color morph cross F1 F2 inheritance experiment"Neocaridina heteropoda" colour morph crossing genetics offspring"Neocaridina davidi" trade line dominance backcross"Crustacyanins as regulators of functional complementation" full text
Candidate sources
- Decoding color variation: genome-wide characterization and expression analysis of pigment pathways in Neocaridina denticulata: included. Directly compares molecular pigment pathways among colour strains but does not report pedigree cross ratios.
- Functional Analysis of the NinaB-like Gene in Body Color Regulation of Neocaridina denticulata sinensis: included. Provides functional and association evidence for one colour pathway but not named trade-line F1, F2 or backcross outcomes.
- Crustacyanins as regulators of functional complementation, cuticle development, lipid metabolism, pigmentation, and immunity in shrimp: candidate. The official preview reports RNA interference, multi-omics and protein-interaction work on a 24-member crustacyanin family, but the full methods and visible phenotype denominators are unavailable and no named trade-line crosses are reported.
Next scheduled search: February 12, 2027. Also governs: named-morph-crosses
Help close or refine this gap
Submit a stable source or correction. A title, abstract or community consensus does not close the gap until its methods and claim boundary are reviewed.