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AQUAPEDIA / SOURCE-LINKED RESEARCH

Marine Blue (Nagaoka)

マリンブルーメダカ

Historical Medaka research identityEvidence by claimIndependent review ongoing

Marine Blue is a pale blue Miyuki-derived line developed by 長岡龍聖 with reduced dark pigmentation and visible exterior light.

Picture gene & lineage tree

Visual pedigree of breeder-reported inputs, where available. Dashed arrows represent documentary claims or selection history, not DNA-tested genes.

Horizontal branching Medaka lineage. American name: Marine Blue (Nagaoka); Japanese romaji: not verified; Japanese characters: マリンブルーメダカ. Dashed connectors show breeder-reported input or selection history; they do not prove genetic parentage. Documented source links and evidence qualifiers follow the diagram.AQUAPEDIA / MEDAKA LINEAGE ATLASSTRAIN PEDIGREEREPORTED LINEAGEDASHED BRANCHES • REPORTED INPUTS / SELECTION STAGESNot an individual-fish pedigree or DNA / dominance test.REPORTED INPUT / STAGE 1Blue Miyuki stock with low-dark-pigmentvariantsREPORTED INPUT / STAGE 2White Miyuki breeding inputsREPORTED INPUT / STAGE 3Selection toward pale sky-blue body withexterior lightFOCAL STRAINAMERICAN / ENGLISH NAMEMarine Blue (Nagaoka)JAPANESE NAME (ROMAJI)Not verifiedJAPANESE LETTERS (日本語)マリンブルーメダカ
Dashed connectors show breeder-reported input or selection history; they do not prove genetic parentage. Not a confirmed genotype or parent-fish identification.

Recorded iterative selection/crossing; does not establish contemporary genotype Source: Medaka WEB Zukan No.0016, Nagaoka Marine Blue origin account

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View this strain’s illustrated gene tree in Discord ↗

Lineage review · Batch 018: Source-described breeder lineage, selected family, or morphology stage is illustrated with dashed documentary links. These are not parent-fish certificates or DNA-tested inheritance. Specialist record ↗

Overview

Marine Blue is a pale blue Miyuki-derived line developed by 長岡龍聖 with reduced dark pigmentation and visible exterior light. The historical shop catalog describes selection away from darker Miyuki body color. Pisces later reports selection from blue Miyuki Super Light stock with white Miyuki inputs. Creator-versus-discoverer status is source-scoped.

Claim-by-claim evidence

Research findingEvidence classDirect references
Historical record: Ryusei Nagaoka / 長岡龍聖 (Romanization provisional) — Breeder-developer historically credited.Archive maker or discoverer attributionE78 ↗
The historical shop catalog describes selection away from darker Miyuki body color. Pisces later reports selection from blue Miyuki Super Light stock with white Miyuki inputs.Source-described historical breeding and development, not independently genotypedE78 ↗ MP ↗ MB ↗
Clearer, pale sky-blue internal appearance alongside visible Miyuki dorsal exterior light.Visual phenotype only; individual expression can varyE78 ↗ MP ↗ MB ↗
Pisces notes that Marine Blue circulated earlier while Shinkai may have been stabilized first; the 2011 catalog heading is not proof of every selection or release order. Historical context: 2011 historical retail visibility, with selection chronology disputed.Editorial distinction grounded in cited source; exact sale dates not guaranteedE78 ↗ MP ↗ MB ↗

Evidence labels refer to documentary strength. They do not assert independently tested genetics.

Known research gaps

  • Marine Blue and Shinkai must remain distinguishable by exterior-light expression and source-reported selection history.
  • Cited first-generation and selected-parent statements do not prove DNA genotype, inheritance rate or present-day breeder-stock identity.
  • No third-party breeder/catalogue image is reproduced; photo rights and original genetic records require independent review.

Related profiles and lineages

Original research sources

Every row above links directly to its cited reference; publication or creation years are not interchangeable.