Attempting to Breed Sawbwa resplendens (Rummynose Rasbora)

Saad said:

What were the water parameters to get them spawn?

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I have soft tap water which the sawbwa resplendens don't like. I added pea pebbles that seemed to raise the GH. I used a matured filter so 0 ammonia, nitrites, and the mass of plants helped with nitrates (I'd consider Floating plants essential for spawning this species)—average PH of 7.66 (These fish prefer 6-8 PH) and 19-22c in temperature.

Slowly approaching the conclusion​

The group has grown up really well and is soon to be selected for stocking my new 90L tank. The remainder will be given away most likely to my LFS, hopefully for a swap or store credit. Many of the fry have now reached the age at which sexing is possible.

• Males - Red/Orange on the nose and the tips of the caudal fin + turning pale blue on the body
• Females - Females are beige + black spot near the anal fin

They remain in the 34L Fluval Flex in which I have removed the majority of potted plants to give more swimming room for the fish. I also removed the water lettuce and the majority of duckweed to reduce the chances of them accidentally spawning since they all have the same parents. They are still fed JBL NOVO BEL (B) flakes and a mixture of larger dry food crushed in a pestle and mortar. Weekly 10% water changes are mainly used to remove the build-up of bladder snail egg clusters + snail and fish poop. It usually takes about 3-4 days to have a thin layer build up on the bottom of the tank. The HOB filter is also working wonders. I usually replace the filter floss once a week since there is no other media except the pre-filter sponge.


The next post will most likely be the end of this thread. This was the first time I've ever bred fish and what an experience it has been. I think the Sawbwa was the perfect choice for me to attempt breeding

It's fun to get new (to you) fish for a tank and watch them - it's something I enjoy, anyway. But it takes it to a new level when you breed them, and raise them. All of a sudden a passive sort of activity, where the main thing you do is take out your wallet becomes a puzzle, an activity, something to test your skills against.

Plus I always have a softer spot for fish I've bred compared to fish I've bought.

Strangely the behaviour of the fish has changed in the last few hours since I removed the other potted plants. They seem to be swimming more in the open than they used to and coming to the front of the tank. Usually, they would stay in the bottom half scavenging amongst the detritus and leftover food, and retreat behind the pots when I approached. No idea if this is a good sign or not.

Most fish sold in pet shops are related. I would keep breeding the ones you have and maybe flood the market with them, then sell most off and start again with something else.

The End​

Today I moved the fry into their new home (90L Tank). I netted 12 fish in total for the 90L (3x male 9x female). With the remaining 9 staying in the 34L until they can be moved on. Most likely to my LFS.


In summary, I started with one adult male and one adult female in the tank. They remained in the tank for 11 days from OCT 1st to 11th. After removal, many fertile eggs (under the floating plants) began to develop black dots. By OCT 14th some eggs hatched and fry were spotted. By OCT 20th many fry were free swimming and eating infusoria. By NOV all fry began to grow rapidly and developed into juveniles. By JAN coloration of the fish started to come through allowing for the start of sexual dimorphism of male and female fish. BY MAR they had reached a size to which I was comfortable transferring them to their new tank.

It has been a thrilling journey breeding these fish. I started with no experience in fish breeding when I started this thread back in Sep 2023. Now I believe I have gained the knowledge and confidence in breeding fish if I were to attempt it again. Thanks to those who helped me along this journey sharing knowledge and advice. I'd especially like to thank @GaryE and @Colin_T for their excellent insight and knowledge.

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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Colin_T is this general advice for breeding most fish or specific to rummynose rasboras?

MuddyWaters said:

Colin_T is this general advice for breeding most fish or specific to rummynose rasboras?

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Virtually any fish that isn't a cichlid or Corydoras. The cichlids tend to pair off and have a cave, plant or rock they breed on. Corydoras are generally group spawners and when one starts, they all start (a lot of other fishes are too). However, most other fishes (tetras, barbs, danios, rasboras, rainbowfish) are egg scatterers and you get best results from a single pair in a tank where nobody else is going to eat the eggs.

All fish being prepared for breeding and during breeding should be fed more often. If they are well fed for a few weeks before they can build up fat reserves and produce good quality eggs & sperm. Well fed fish are much less inclined to eating their eggs or young.

To second Colin's post - I breed Aphyosemion killies. They lay eggs every day, in small numbers. If I collect 3 or 4 eggs from some generous species, that's a good haul. If I separate them even for 3-4 days, and feed them good live food, then combine, I've gotten 25 eggs in a day. With species that give one egg on a good day, a sudden burst of 3 to five eggs can follow a simple feeding with a live food I haven't given them for a couple of weeks. Their bodies grab any extra energy and throw it into egg production.

I'm waiting to see if my attempt at Hyphessobrycon negodagua from 3 days ago pans out. Nothing is ever guaranteed, and yields can be tiny. But as hobbyists, we don't need 10,000 tetras.

Good stuff guys thanks. I would like to breed my green fire tetras at some point just to try and do it. Same with the angelfish. I definitely don't want a ton of new ones, but just to be able to help facilitate the conditions needed for them to do their thing is really cool. Angelfish are supposed to be relatively easy, so I'm waiting for mine to start pairing off. I have no idea how to get the green fire tetras to mate, but it's on the list of stuff to try ;-)

@MattW3344 - seeing your process and watching you do this is inspirational- I'm in the same boat- never tried it- always seems so difficult, but nice to see someone make it work on the first try!

MuddyWaters said:

Good stuff guys thanks. I would like to breed my green fire tetras at some point just to try and do it. Same with the angelfish. I definitely don't want a ton of new ones, but just to be able to help facilitate the conditions needed for them to do their thing is really cool. Angelfish are supposed to be relatively easy, so I'm waiting for mine to start pairing off. I have no idea how to get the green fire tetras to mate, but it's on the list of stuff to try ;-)

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Angelfish will breed when they mature and are well fed. They mature at around 12 months of age, depending on temperature and food. Warm water (28C) with big regular water changes and gravel cleaning, and lots of food makes them grow faster.

Tetras should be sexually mature at 3-6 months of age. Separate males and females for 5 days and then put a pair together in a tank. Most tetras need soft water with a pH below 7.0 to breed. Having some tannins in the water can definitely help. For South American blackwater tetras like cardinal and neons, you want a pH around 6.0 and a GH and KH of 0ppm, and some tannins. To get this water you use rain water, distilled water or reverse osmosis water and then add some peat, Indian almond or oak leaves, or driftwood and let the water turn brown. Separate the prs for 5 days, then put a pr in the tank with the black water (tannin stained water).

Tetra eggs are photosensitive and won't develop if there is a lot of light so do not have a light above the breeding tank. Put some black card around the back and sides of the tank, and put a piece on the front after the fish have bred and you have removed the adults. Keep the tank dark until you see the fry stuck to the side of the glass or swimming around the water just under the surface. Then you can remove the black card from the front and have a low wattage near the tank so the fry can feed.

Tetras need green water and or infusoria as their first food. They live on this for the first 2 weeks of life and then eat newly hatched brineshrimp. After a week or two on brineshrimp you can add microworms too. You can feed them on powdered fry food too. Feed a variety of foods with newly hatched brineshrimp as the main part of the diet until the fry are about 1 inch long. Add new foods as they grow.

The following link has info on culturing live foods for baby fish.

Video of the journey ​