Hi Utsuri Koi Care Guide: Red on Black Variety

Hi utsuri stand out in any koi pond because their pattern reads inverted — red riding on a base of deep sumi black, rather than the more familiar black-on-white sanke. The hi utsuri koi sits in the Utsurimono category alongside ki utsuri (yellow-on-black) and shiro utsuri (white-on-black), and quality fish command serious money at Singapore importers. This guide from Gensou Aquascaping at 5 Everton Park covers the breed’s lineage, judging benchmarks, and what to look for when buying tategoi candidates from Niigata-line stock.

Lineage and Variety Background

Hi utsuri descend from the original Magoi black wild carp via the Utsurimono breeding program developed in early 20th century Niigata. Cyprinus rubrofuscus in this form layers red (hi) plates over a black sumi base; the black should reach completely down to the belly line, not just the upper flank. Modern hi utsuri come from Dainichi, Sakai Fish Farm and Marudo bloodlines. The pattern develops through life, with sumi typically darkening through ages 3-5.

Judging Standards and Pattern

ZNA standards reward sumi that wraps fully around the body, hi that sits in clean blocks (not scattered patches), and a motoguro (black pectoral fin base) on each side. Penalty marks come from secondary hi stains on the head, broken sumi edges (kiwa), and faded shiroji underbelly. Top-grade hi utsuri show a powerful body shape, deep volume through the shoulders, and balanced hi distribution from head to tail. The head pattern is critical — solid hi over the face is preferred.

Pond and Water Requirements

Hi utsuri grow large — 60-80 cm common at age six to eight. Pond minimum is 5000 litres at 1.2 m depth for a single specimen, more for a small group. Strong biological filtration runs 2-3x pond volume per hour through bead filters or moving bed media. Singapore tropical conditions encourage year-round growth, but the heat (28-31°C) accelerates metabolism so feeding and filtration must scale up. Use kit from the aquarium equipment range for pump, drum filter and UV.

Water Chemistry Targets

Target pH 7.2-7.8, KH 5-7, GH 8-12, ammonia and nitrite zero, nitrate under 40 ppm. PUB tap is soft and needs KH buffering — crushed coral in the filter or a measured KH+ product works. The sumi pattern responds to water hardness; soft acidic water dulls the black over time. Test weekly. Treat water with conditioner from the water care and treatment shelf at every change.

Feeding for Sumi and Hi Development

Hi utsuri benefit from colour-enhancing feed during the warmer months when growth peaks. Use a base of high-protein wheatgerm pellet (38-40 per cent protein) with a colour-boost feed (containing spirulina, krill and astaxanthin) once daily. Saki-Hikari Colour Enhancing and Hikari Wheatgerm sit in the SGD 65-160 per 5 kg range from the fish food and feeding range. Avoid over-feeding the colour boost — too much astaxanthin bleeds the white shoulder areas.

Common Health Issues

Sumi-heavy varieties show parasitic damage faster than light-coloured koi because the black contrasts with mucus loss. Quarantine all imports for 30 days at 22-26°C. Watch for flukes, trichodina, and aeromonas. Praziquantel for flukes, formalin for trichodina, salt baths and oxytetracycline for ulcers. KHV remains the catastrophic risk — never skip the quarantine.

Singapore Sourcing and Pricing

Hi utsuri sit at SGD 80-500 for tosai (one-year, 15-25 cm) at Singapore importers like Yamamatsu Singapore, Marudo Carp Farm imports, and Shintaro distributors. Two-year nisai stock at 30-40 cm reaches SGD 800-3000. Show-grade adults from Dainichi or Sakai bloodlines push into SGD 8000+. Always view the fish in person, in a tub with shallow water, ideally under shaded daylight. Buy through reputable agents who can document the breeder and bloodline.

Related Reading

• Ki Utsuri Koi Care Guide
• Chagoi Koi Care Guide
• Kujaku Koi Variety Care Guide
• Koi Judging Criteria Show Prep Guide
• Koi Tategoi Selection Criteria Guide