Attempting to Breed Sawbwa resplendens (Rummynose Rasbora)

I've made a few posts about this fish especially on finding females since I only have 1. I was asked in a recent post why I didn't attempt to breed with just that 1 female. I have never attempted to breed fish before so I thought I'd give it a go since the odds of finding a female are slim.

I did some general research on this fish. I mainly used this site and a mini-series on YT from 2017.


These fish breed within floating plant islands in the wild so I used some cuttings from a stem plant and some old java fern from a bucket to create this. I also transferred some floating plants from my main tank to help with filtration. This tank will be left for a day or two to adjust with daily water testing to find any irregularities. I also put a mini sponge filter and ceramic media in my main tank for a few weeks to increase bacteria colonies for when the fish eventually go into the breeding tank.

I have had these fish breed in the main tank before but most of the eggs were eaten by my gourami. So hopefully isolating the eggs in a separate tank from predators will give me better odds of successfully breeding this species.

First, if you call them rummynoses, you will get piles of wrong comments. 99.9% of people think of South American tetras with that name. So filter the incoming comments.

I found a great article months ago when I was considering these fish. It was from a guy in an aquarium club who bred them 20 years ago. I can't come up with it again. The fish has too many names (Burmese rummys, Asian rummys, blue Sawbwa, Sawbwa respelendens, Swabwa rummynoses...). I recall he used pairs, which most of the articles don't suggest, and he talked of low numbers of fry, but enough success he was was happy with them. He would raise 5 or 10 each spawning, which wasn't going to give him fish to sell, but gave him enough to build his group.

GaryE said:

First, if you call them rummynoses, you will get piles of wrong comments. 99.9% of people think of South American tetras with that name. So filter the incoming comments.

I found a great article months ago when I was considering these fish. It was from a guy in an aquarium club who bred them 20 years ago. I can't come up with it again. The fish has too many names (Burmese rummys, Asian rummys, blue Sawbwa, Sawbwa respelendens, Swabwa rummynoses...). I recall he used pairs, which most of the articles don't suggest, and he talked of low numbers of fry, but enough success he was was happy with them. He would raise 5 or 10 each spawning, which wasn't going to give him fish to sell, but gave him enough to build his group.

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The mini series on YT also suggested pairs They used only 4 fish (2 of each) and got 3 fry on the first spawn. I'm thinking of using my oldest male for breeding (one in the pic). I got 2 other males a week ago from my LFS so as I see it I have 2 genetic pools to play with.

It's surprising how quickly you can build a group with fish that spawn in low numbers. You have to be wary that even if adults don't eat fry, in many species, fry 2 or 3 weeks apart will eat their younger siblings. That can create a technical/space issue for rearing them, since they need better conditions than most adults. But you can grow a lot til they can safely live in the parents' tank, then reuse the breeding tank, rear a bunch more, and soon you have a group of 15, or 20, etc. it doesn't look like a fish you should be in a hurry with, but then again, I have to wait all winter for my garden to come alive again. Patience and nature go together.

You need a substrate on the bottom of the tank to help camouflage the eggs. Marbles or gravel will do but marbles are better for fish that eat their eggs. One layer of marbles is normally sufficient. You can put them on top of a thin layer of brown gravel.

This is also why you only have 1pr per tank. If the fish are breeding, they are less likely to eat the eggs. Whereas other fish in the tank that aren't breeding at the time will see eggs as food.

You should remove the worm feeders from the tank. If a fish gets into one it will panic and could injure itself, and no more breeding for a while.

Feed the adults 3-5 times a day for at least 2 weeks before breeding so they develop good quality gametes. Do more regular water changes and gravel cleans when feeding more often.

Separate males and females for 5 days before breeding so the fish can build up some eggs. You should get more young that way.

Introduce the female in the afternoon and the male a few hours later. Let morning sun shine into the tank and they should breed the following morning.

Make sure you have a coverglass on the tank to stop them jumping out.

Colin_T said:

You need a substrate on the bottom of the tank to help camouflage the eggs. Marbles or gravel will do but marbles are better for fish that eat their eggs. One layer of marbles is normally sufficient. You can put them on top of a thin layer of brown gravel.

This is also why you only have 1pr per tank. If the fish are breeding, they are less likely to eat the eggs. Whereas other fish in the tank that aren't breeding at the time will see eggs as food.

You should remove the worm feeders from the tank. If a fish gets into one it will panic and could injure itself, and no more breeding for a while.

Feed the adults 3-5 times a day for at least 2 weeks before breeding so they develop good quality gametes. Do more regular water changes and gravel cleans when feeding more often.

Separate males and females for 5 days before breeding so the fish can build up some eggs. You should get more young that way.

Introduce the female in the afternoon and the male a few hours later. Let morning sun shine into the tank and they should breed the following morning.

Make sure you have a coverglass on the tank to stop them jumping out.

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Thanks for the info! Would pea pebbles and ceramic media (bio rings) be an okay alternative to marble substrate?

Just found one of the floating plants that I moved from the main tank to the breeding tank already has eggs on it! No idea if they are fertile though

Pea gravel will be fine. I wouldn't use ceramic bio media tho

There's more eggs on the other side of that plant too. Which leads me to an alternative for you. Use spawning mops or plants in the main tank and take them out each day to put in a hatching tank. You won't have to move the adults, which could cause them to stop breeding, and the fry will be isolated from the adults so they don't get eaten.

Colin_T said:

Pea gravel will be fine. I wouldn't use ceramic bio media tho

There's more eggs on the other side of that plant too. Which leads me to an alternative for you. Use spawning mops or plants in the main tank and take them out each day to put in a hatching tank. You won't have to move the adults, which could cause them to stop breeding, and the fry will be isolated from the adults so they don't get eaten.

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That would make my life and theirs much easier

Spawning mops, you say? As a killie guy, I have mop making skills. I can tell you how if you need that.

GaryE said:

Spawning mops, you say? As a killie guy, I have mop making skills. I can tell you how if you need that.

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I have mopping skills too

Hey Gary, do you use foam or plastic airline for holding the threads of yarn

Neither.

I use acrylic yarn, and wrap 40 or so strands around a hardcover book the height I want the mop to be. Then I fish one strand of yarn under the top, and tie it off with long strands hanging out. They are tied to a cork, a small floating bottle or a chunk of styrofoam. I cut the bottom, and voila, a spawning mop.

I've been using them made that way for 35 years. That doesn't mean the method can't be improved, but it works for me.

I use them with killies and rainbows, and are now experimenting with using them for Neolebias Characins.

They're ugly as our politicians, but they work when I need to use them.

Grabbed these from LFS as well If I ever do get any fry that is

Have a read through the following link and make a couple of green water cultures and some infusoria cultures. Use 40 litre plus plastic storage containers for the cultures and you will have an endless supply of live food for the newly hatched fish.

Male and female were added less than 48 hours ago and already have new eggs! Again I have no idea if fertile