Karashigoi Koi: How Marudo Koi Farm Created a Jumbo Powerhouse

Karashigoi Koi from Marudo Koi Farm are in a class of their own. Known for their jumbo-growing potential, these yellow-skinned powerhouses are bred from exceptional bloodlines with genetics built for size, structure, and stability.

What Makes Marudo’s Karashigoi So Special?

Mujimono — single-coloured koi — might not always grab headlines, but Marudo’s reputation for producing dominant, fast-growing Karashigoi is unmatched. While the farm is globally respected for its Go-Sanke, it also ranks just behind Marusei for developing standout single-colour varieties such as Chagoi, Ginrin Chagoi, and of course, Karashigoi.

The breeder’s inspiration began during his apprenticeship at Dainichi Koi Farm, where visits to Marusei exposed him to 80–100cm single-colour koi. That fascination turned into a vision — and eventually, into the powerful fish now being grown in the UK.

Remarkable Growth in Just Weeks

This particular batch of Karashigoi Koi arrived at just 12–15cm. In less than two months, many have already grown to 22–26cm in one of Ricky Stoddart’s 1,200-gallon ponds — an astonishing growth rate backed by powerhouse genetics.

The initial selection focused on size grading to reduce numbers and give the remaining fish more space to push forward. Ricky noted that even the smaller koi could thrive in less competitive environments, reinforcing the importance of understanding growth patterns within each spawn.

🎥 Watch the Selection Process at Marudo Koi Farm

See the fish in action and follow Ricky’s commentary as he selects these incredible Karashigoi from the source:

The Story Behind the Bloodline

Marudo’s Karashigoi line has deep roots. It began with a legendary Chagoi from Toyama, produced by crossing standard Chagoi with Kurogoi (a black variant). These fish reached 100–120cm and displayed Kohaku-style shoulder and head characteristics.

One of these impressive koi featured in Rinko magazine caught Marudo’s eye — and became the cornerstone of his own Chagoi line. To create his Karashigoi line, he crossed that Chagoi with a male from the famous Konishi Karashigoi line, combining powerhouse traits from both farms to establish the exceptional fish we see today.

Today’s fish are second-generation Karashigoi, bred purely at Marudo Koi Farm, and represent the best of both strength and elegance.

Understanding Body Structure and What to Look For in Karashigoi

One of the standout features of Karashigoi Koi from Marudo Koi Farm is their powerful body structure. These fish are built to grow long and strong, but also to do so in balance.

• Head-to-dorsal distance: A long stretch here indicates potential for overall length.
• Backbone visibility: Prominent backbones suggest robust bone structure.
• Peduncle strength: The taper into the tail should be powerful and thick.
• Proportional thickness: A lean yet broad frame early on helps avoid stunting and builds future volume.

When selecting young Karashigoi, these body traits take priority over colour — which is typically consistent in this bloodline.

Doitsu Karashigoi – A Closer Look at an Eye-Catching Variant

Among the batch are several Doitsu Karashigoi, a scale-less variety that adds a unique visual appeal to any collection. These koi stand out with their distinctive skin texture and fascinating scale patterns.

• Aragoke-style scaling: Scattered and irregular, adding rugged character.
• Linear lines: Uniform, symmetrical scales running along the lateral or dorsal lines.

Doitsu Karashigoi can grow just as well as their fully scaled (Wagoi) counterparts, especially when supported by Marudo’s genetics. These are a favourite for koi keepers who want both size and striking aesthetics.

The Power of Jumbo Genetics – Why Lineage Matters

What sets this batch apart isn't just their size now — it's their genetic potential. The parent fish in the Marudo line are all over 100cm, including both Chagoi and Karashigoi types.

• Predictable growth: Backed by proven results across generations.
• Reliable body structure: Clean lines, big heads, strong shoulders.
• Effortless progress: With proper care, these koi grow quickly and consistently.

Final Thoughts

Backed by legendary genetics and already showing phenomenal growth, these Karashigoi Koi from Marudo Koi Farm are among the most exciting single-colour koi lines available today. Whether you’re focused on jumbo potential, body refinement, or bloodline development, there’s a wealth of insight to be gained from following their journey.

Interested in exploring koi from top breeders like Marudo? Browse our latest Japanese Koi for Sale — hand-selected with care, expertise, and a passion for quality.