Kujaku Koi Variety Care Guide: Peacock Metallic
Kujaku is one of the most visually complex koi in the Hikarimoyo (metallic patterned) classification — a peacock-like reticulated net pattern of dark-edged scales over a metallic platinum or gold base, with red or orange overlays. The kujaku koi is regularly confused with Goshiki, but the metallic platinum sheen separates them clearly once you know what to look for. This guide from Gensou Aquascaping at 5 Everton Park covers the breed’s lineage, judging criteria, and how to source quality kujaku tategoi candidates from Singapore importers.
Kujaku Lineage and Origin
Cyprinus rubrofuscus in kujaku form was developed in 1960 by breeder Toshio Hirasawa from a cross between Hariwake (metallic platinum-and-orange) and matsuba (pinecone-pattern net scaling). The result combines the metallic luster of the Hariwake parent with the reticulated dark-edge scaling of the matsuba. Modern kujaku come from Hirasawa, Marudo, and Sakai Fish Farm bloodlines. Body matures at 55-75 cm.
Kujaku vs Goshiki: The Distinction
Goshiki shows five colours over a non-metallic base, with the dark net scaling overlaid on white-and-red ground. Kujaku is metallic — the platinum or pearl base reflects light, and the matsuba pattern sits on top of that shimmer. Hold the fish under daylight: kujaku flashes; goshiki holds matte. The hi (red/orange) on kujaku is also more vibrantly orange because the metallic underlayer brightens the colour beneath.
Judging Criteria
ZNA standards judge kujaku on metallic luster (must be uniform across the body), clarity of the matsuba pattern (each scale individually defined), hi distribution (balanced and clean-edged), and body conformation. Penalty marks for missing scales (which break the matsuba pattern), dull luster, or hi that bleeds beyond scale boundaries. Head pattern matters — solid hi over the face is preferred. The pectoral fins should show metallic platinum without secondary patches.
Pond Setup and Filtration
Kujaku reach 60-70 cm commonly. A single fish wants 4500 litres at 1.2 m depth; a group of five wants 18,000-25,000 litres. Filtration runs 2x volume per hour through drum, bead or moving-bed media. Singapore tropical conditions support continuous growth, so filtration must scale to handle the bioload. UV sterilisers help maintain water clarity which shows off the metallic luster. Pump and filter kit from the aquarium equipment range supports the build.
Water Chemistry for Luster
Target pH 7.2-7.8, KH 5-7, GH 8-12. Metallic koi like kujaku show their full luster only in clean, hard water. Soft acidic conditions dull the platinum sheen over months. Buffer KH actively with crushed coral or a measured KH+ supplement. Ammonia zero; nitrite zero; nitrate under 30 ppm. Run weekly 20 per cent water changes treated with conditioner from the water care and treatment shelf.
Feeding for Pattern Definition
Kujaku benefit from carotenoid-balanced feed to deepen the hi without overpowering the platinum. Use Saki-Hikari Wheatgerm as the base with Saki-Hikari Colour Enhancing two to three days per week during warm months. Over-feeding colour enhancer pinks out the white-platinum areas. Three feedings daily, scaled by water temperature. Stock options at the fish food and feeding range include Hikari Friend and Saki-Hikari brands.
Health and Quarantine
Quarantine 30 days at 22-26°C for all imports. Watch for flukes, trichodina, costia and aeromonas ulcers. Praziquantel at 5 mg per litre handles flukes; formalin or salt for trichodina. The metallic skin shows damage clearly — small scrapes or scale loss appear darker against the platinum and demand immediate response. Singapore koi vet visits run SGD 150-300 for diagnostic and treatment advice.
Singapore Sourcing and Pricing
Kujaku tosai at 15-25 cm runs SGD 60-400 at quality-focused Singapore importers. Two-year nisai at 35-45 cm reaches SGD 800-3000. Show-grade adults from Hirasawa or Sakai bloodlines push past SGD 6000-20000. Yamamatsu Singapore and Shintaro Carp distributors handle premium imports. Inspect under shallow water with overhead daylight — the metallic flash and matsuba clarity reveal under natural light far better than indoor LEDs. Buy with bloodline documentation when possible.
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