Tamasaba Myths: Are They Really Different From Ryukin?

In recent years, Tamasaba Goldfish have been gaining attention in the hobby. They’re often promoted as one of the few “Fancy” Goldfish that can thrive in ponds — alongside favourites like the Wakin, Watonai, and Bristol Shubunkin.

But here’s the big question:

How is a Tamasaba different from a Ryukin?

The short answer: not by much.

Most of the striking new Tamasaba colours actually trace straight back to Ryukin bloodlines. Some Tamasaba are just a couple of generations away from Ryukin, and in some cases, they may simply be Ryukin with a single tail. Let’s dig into the myths and the reality.

Where Do Tamasaba Come From?

Fancy Goldfish breeders know the most important (and difficult) part of the process is culling — removing fry that don’t match the breed standard.

One of the first things you cull for is tail type. In Fancy Goldfish spawns, you often see anywhere from 5% to nearly 100% single-tailed fry appear. (I’ve even had whole spawns of single-tailed fish that should have been fancy Ryukin spawns!)

So how did the Tamasaba appear?

At some point, breeders likely thought:“Instead of discarding these single-tailed fry, what if we gave them a name and marketed them as something new?”

That may be how the Tamasaba Goldfish became recognised: a Ryukin offshoot that was refined and promoted as a unique variety. Rather than calling them “waste,” I’d say they’re byproducts of Ryukin breeding that got their own spotlight.

Tamasaba vs Ryukin: What’s the Real Difference?

When you place the two side by side, the similarities are undeniable.

• Body shape? Ryukin.

• Hump? Ryukin.

• Finnage? Ryukin.

The only clear difference? Tamasaba have a single flowing tail, while Ryukin are double-tailed.

And that’s it. Same fish, just a different tail outcome.

That doesn’t mean they aren’t beautiful — they absolutely are — but it does raise a point about the value of selection.

With Ryukin, you may only get 10–50% of fry that are worth keeping, due to the strict standards for double tails. With Tamasaba, suddenly you’ve got close to 100% acceptable tails, which lowers the difficulty and labour in producing them.

From a breeder’s perspective, that makes Tamasaba easier to produce — but in my eyes, it also means they’re less of a challenge and therefore a little devalued compared to their Ryukin relatives.

Ryukin or Tamasaba? (Can you even tell from this angle?)

Marketing the Tamasaba: Why Koi Keepers Love Them

One of the most interesting things about the Tamasaba story is how they’ve been marketed. Unlike most Goldfish varieties, Tamasaba are not usually described with traditional Goldfish terminology. Instead, they’re often promoted directly to the Koi hobbyist market.

Why? Likely because Goldfish breeders know exactly what they’re looking at — a single-tailed Ryukin — while Koi keepers see something fresh, hardy, and exotic.

The colours of Tamasaba are often described in terms of Koi patterns (like Kohaku, Sanke, or Showa-style markings), even though genetically they’re completely different from Koi. It’s clever marketing: by borrowing Koi language, sellers make Tamasaba feel more familiar and appealing to pond keepers already invested in Koi culture.

The Problem: Overvalued and Overproduced

Here’s the blunt truth: Tamasaba are heavily overvalued.

They rely on clever marketing and Koi-styled naming to be sold at higher prices than an equally high-quality Ryukin. Add-in inflated demand — with hobbyists believing they’re something rare or special — and the fact that they’re so easy to mass-produce, and you’ve got the perfect scenario for profit-driven breeding.

For a money-hungry breeder, it’s a dream come true:

• High demand.

• High supply.

• Low difficulty in production.

• Big margins compared to a Ryukin of the same standard.

  
  

That doesn’t make them bad fish — but it does mean a lot of their current popularity is less about the fish themselves, and more about marketing hype and inflated pricing.

Are Tamasaba Goldfish Good Pond Fish?

Now, let’s be fair to the Tamasaba — they do have some advantages.

• Stronger swimmers: Thanks to their single tails, Tamasaba swim more efficiently than double-tailed fancies. This makes them better suited for outdoor ponds, where they can hold their own with Koi or larger fish.

• Cold hardiness: Some keepers claim Tamasaba are more cold-hardy than other fancies. In certain cases this may be true, but remember — they’re still the same species as Ryukin. The only real difference comes from breeding practices.

Because Tamasaba produce in greater numbers, breeders could focus more on selecting for health and hardiness traits instead of just colour or finnage. If that was consistently done, it would genuinely make them one of the best Fancy Goldfish for ponds.

The reality? In large-scale commercial breeding, the focus is often still on quantity and marketability rather than long-term health.

The Takeaway on Tamasaba

So, are Tamasaba some ancient, rare Japanese mystery goldfish? No.

Are they beautiful, hardy, and a great option for ponds? Yes.

Here’s the interesting part though: Tamasaba are actually an old variety. They existed historically, but lost popularity for many decades. It’s only within the last 10 years or so that they’ve been pushed back into the spotlight — but by then, very little of the original genetics remained.

What we see today as “Tamasaba” are essentially just single-tailed Ryukin. And in a funny twist of history, it’s believed that Ryukin themselves originally descended from Tamasaba, or from something very similar.

So now we’ve come full circle:

• The old Tamasaba gave rise to the Ryukin.

• And today’s Tamasaba mostly come from Ryukin.

  
  

An odd little loop in Goldfish breeding — and a great example of how marketing, history, and hobby trends shape what ends up in our ponds.

If you love their look, they’re still a fantastic choice — just remember they’re not a completely new species, and definitely not as rare as the hype would have you believe. Add some comparison pictures of Ryukin vs Tamasaba, and you’ll see just how closely the two are tied together.

Tamasaba (or is it?)

Broadtail Ryukin

Thank you for taking the time to delve into this post. We'd be thrilled to hear about your experiences with Goldfish breeding. What challenges have you encountered, and what successes have brought joy to your aquatic endeavours? Your insights enrich our community, so please feel free to share your thoughts.