# Medaka



## Steven_Chong

So I am in Tokyo right now guys (doing study abroad here for the next four months), and I came accross this little gem of a fish here in Japan, apparently it's a hobby in and of itself. The Medaka is a small kilifish that maxes out at about 4cm (1.6in), can live in ridiculously small spaces, convert between brakish and freshwater, breeds profusely, and is hardy in shipment. Apparently, according to wikipedia, they are a well established lab-animal. The normal Medaka also weighs in price-wise at a meager 100yen (about a dollar). In the Japanese pet scene though, they can be found not only in the normal grey, but in full body tan, yellow, white and even orange.

My question then: Why the hell haven't I heard about these little fish in the hobby before?

I mean, yes I've heard about them before now, but why aren't they a regular distributable in the hobby? I mean 100 yen for a fish that tiny seems like a great nature aquarium candidate to me (yes, ADA has used these guys).

The only drawback I see is that their natural lifespan is about a year. 

But then, the same is for red bee shrimp so. 

Anyway, anyone got any information on where/how/if one can obtain these little guys in the states? I'd love to keep them even after coming back home from Japan.


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## cholly

Frank's usually seems to have a couple of species around, see http://www.franksaquarium.com/misc.htm or Arizona Aquatic Gardens has them sometimes, too: http://www.azgardens.com/misc_fish.php

Rice fish are usually obtainable, it's just a question of looking around for them.


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## Brilliant

Killifish have a huge following in the US. You should check out one of the clubs when you return. They are interesting fish to get into and like you say a hobby in itself.


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## zoggin eck

Here in Australia you can find Oryzias latipes, the medaka or ricefish in any store, at the end among other "coldwater" tanks along with white clouds etc.

They are lovely fish, and one thing that has always surprised me is how little they feature in the tanks of people who take the hobby seriously.

One thing you didn't mention was the temperature range of these guys. I have some in a pond which ranges from 40 deg celsius to less than ten. They do breed easily, with the female carrying eggs behind her, with the eggs later sticking to plants. You can often see the eggs carried about in the store (an easy way to sex them too ) and apparently the fertilization can be internal as well as external.

The fry also grow up quickly. I watched a baby grow from a speck to half the adult size in just a few weeks, outstripping even my guppy fry.

The colour I usually see is the gold version, hence "gold medaka". I was also lucky enough to get a few white/silver ones at one store mixed in with the gold. This colour can also vary. My pond ones, when well fed and happy have glowing red fins which really stand out. I have taken them out just to have a look a few times  They are also active, and stay around the top, so look good in open top tanks.


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## lampeye

They're no longer killies - they were kicked out of the Cyprinodontiformes some time ago. most of us still consider them "honorary" killies. I had some gold medakas many years ago.

They are a PAIN to find in the States. Had I known it would be like this, I would have hung onto my golds - they bred like rats and bored me. I tried importing some from Japan last year, but shipping regs made it unworkable for me. If you were to ship some eggs to the states while you were there, you could make yourself a lot of friends.

Your post both gladdens and saddens - I'm glad to hear someone else appreciates these fish, but I would have thought they'd be fairly well represented in Hawaii, with its large Japanese-American population. That you haven't seen them around before doesn't bode well for that theory.


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## toddnbecka

> I would have thought they'd be fairly well represented in Hawaii, with its large Japanese-American population.


Restricted from import as potentially invasive?


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## Medaka

Japanese medakas are very scarce in US, and most of the ones here are not very good quality. In Japan there are hundreds of active hobbyist breeders specializing in different strains, but in the US you would be lucky to find anyone breeding plain Jane gold medakas. I'm pretty sure that I am one of the few, if not the only, active Japanese medaka breeder in the US. Right now, I'm breeding two different color strains -- buchimedakas and himedakas. Himedakas are what we call "gold" (gold in Japan is really metallic gold colored) and buchimedakas are a top-view fish with a mottled color pattern.

FYI: Japanese medakas are legal in Hawaii, I guess they're just as unpopular there as they are on the mainland.


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## Felf808

Unpopular in Hawaii is right; family and friends used to refer to them as bait for bass in lake wilson


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## Medaka

At least someone has heard of them in Hawaii! I assume the wild form was introduced as a form of mosquito control? However, I think any small non-game fish is called bait by fishermen. I bet neon tetras would make good bait in Brazil, and I know some of our pretty top-minnows are used as bait here in the states.

The problem with importing newer strains into Hawaii is that you need two licenses to import fish from overseas, a federal and state license. Probably no one has gone through the trouble of obtaining both. The Hawaii license isn't that expensive if the species is on the clean list, but it requires the breeder/dealer (even if they live in the US) to fill out the proper documents to "export" the fishes to Hawaii. Most foreigners, much less US breeders, wouldn't bother with all the bureaucratic hassles involved.

I should also clear up one of the myths in this thread. _Oryzias latipes_ actually lives 1.5 to 2 years if kept in an aquarium at ambient temperature. If exposed to seasonal weather (i.e. a small pond), they live between 2 to 4 years. Possibly, if kept at at a constant of 80 plus degrees they might die within a year's time, but I haven't tried that yet. When they die, they die like most fishes, they lose their color, bloat up, and become lethargic.


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## TAB

I was in a LFS yesterday, they had 50 or so of "blue eye rice fish" for $2/each

they were actually pretty attractive fish. I was killing time waiting for a bid otherwise I would have bought some.


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## Squawkbert

So, do you ship eggs?



Medaka said:


> Japanese medakas are very scarce in US, and most of the ones here are not very good quality. In Japan there are hundreds of active hobbyist breeders specializing in different strains, but in the US you would be lucky to find anyone breeding plain Jane gold medakas. I'm pretty sure that I am one of the few, if not the only, active Japanese medaka breeder in the US. Right now, I'm breeding two different color strains -- buchimedakas and himedakas. Himedakas are what we call "gold" (gold in Japan is really metallic gold colored) and buchimedakas are a top-view fish with a mottled color pattern.
> 
> FYI: Japanese medakas are legal in Hawaii, I guess they're just as unpopular there as they are on the mainland.


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## Medaka

The current selection of wild medakas in the trade aren't very closely related to _Oryzias latipes_ despite being congeners. (They originated from a common ancestor over 30 million years ago!) They are much more fragile than the Japanese medaka, but they are great fish, nonetheless. I have kept and bred several of them so far. I bet they will still be at your LFS when you return. I have had a difficult time selling the ones I have breed in the past. Not enough color, I guess.


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## Medaka

Yes and I ship fish, too. I currently don't have any eggs, but I do have about a hundred fry in various stages of development. The mature ones I have are already sold, but the next batch should be ready in a month. My fish might also spawn soon, but they haven't spawned in over a week. I use natural lighting... it's hard to control when they spawn.


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## Medaka

I just noticed there's no medaka pictures in this thread! Here's a picture of a nice looking male hi-medaka. This strain is a side-view (aquarium) color and body form. I'll upload a profile shot once I get around to it. Enjoy!


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## Felf808

I never thought of them as "nice fish" but now I'm starting to see how they'd fit in a nature aquarium. I still think of them as bait because we used to catch some nice bottom fish while using them


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## lampeye

Medaka said:


> The current selection of wild medakas in the trade aren't very closely related to _Oryzias latipes_ despite being congeners. (They originated from a common ancestor over 30 million years ago!) They are much more fragile than the Japanese medaka, but they are great fish, nonetheless. I have kept and bred several of them so far. I bet they will still be at your LFS when you return. I have had a difficult time selling the ones I have breed in the past. Not enough color, I guess.


At least in the US, _Oryzias dancena_ (formerly called melastigma) and _O. javanicus_ show up somewhat regularly. They are the "blue-eyed rice fish" or "Indian lampeyes" that one sees in pet stores.

_O. latipes_ is harder to find, but is out there. I tried importing some from a hobbyist in Japan a few years back, and got little to no help with shipping methods and regulations, despite contacting F&W and several venerable oldtimer hobbyists who have imported fish from Germany and the Netherlands. The general response, when I got one, was "shipping from Japan would be different." :frusty: The hobbyist himself had never shipped internationally, so the plan to import some of the white form, the red form, golds and wild-types went down in flames.

Felf - I don't think the true medaka is established anywhere in the islands. Most likely you were catching gambusia, which are, and which are often called "medaka" by Japanese-Amenericans due to their slight resemblence when seen from above.


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## Felf808

Very likely but I'm sure "gambusia" can have a certain appeal as well.


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## armedbiggiet

can you share more pics? I still not sure what they are.


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## Mizuho Medaka

We are breeding and selling Medaka in Hong Kong. Our Medaka are come Japanese winning bloodlines. We would be shipping our Medaka to overseas. Please feel free to contact us if you have any queries.

Our email address: [email protected]

Thank you

Mizuho Medaka
Emi Kyufoka & Abel Choi


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