My Betta Fish Laid Eggs: What to Do Next

My Betta fish laid eggs after two short-finned fish were mistakenly sold to me as females. If this happens, separate the adult female, protect the filter intake, prepare tiny fry food, and plan a safe home for each adult before doing anything else.

The Merck Veterinary Manual guide to fish reproduction describes Bettas as bubble-nest builders and explains that newborn fish need species-appropriate water, cover, gentle filtration, and tiny food.

Accidental Betta Spawn Steps At A Glance

1. Move the female to her own heated, filtered aquarium and check both adults for injuries.
2. Leave the male with the nest only while he is tending eggs and newly hatched fry.
3. Protect every intake and prepare a cycled, gentle sponge filter for the fry.
4. Start tiny live-food cultures before the fry become free-swimming.
5. Remove the male when the fry are free-swimming, then test the nursery water every day.

The fish glow under blue aquarium lighting, but they still need a normal dark period. Use blue light briefly for viewing instead of leaving it on through the night.

After a few days, I saw one fish making a bubble nest. I assumed both fish were female because male Bettas were pictured in my mind as having long, flowing fins.

I never knew you could get short-fin Betta fish called Plakat, and the pet shop did not sell us two females but a male and a female. If you have short-fin Bettas, it helps to know how to tell a Plakat male from a female before you end up in the same situation. So I got to the tank in the morning and saw eggs in those bubbles. Still, it did not occur to me that one could be a male. In my mind, Betta males had these impressive, long, flowing fins and tails.

I felt sorry for “her”; “she” was being such a good mom, picking up the falling “unfertilized” eggs and placing them back into the bubbles, silly me. Only the next morning, when I saw the babies, did panic hit me like a plank between the eyes. I was excited and freaking out at the same time as I realized how unprepared I was for the babies.

What I Bought / What You Need

As I walked into the pet shop, I naturally had the attitude of, “Two females, yeah, right!” I explained to the pet shop that the breeder they got these GloFish Bettas from was incorrect when he told them they were all females and were the short-fin variety.

Anyway, at the pet shop, I got the following items:

• A self-floating multifunctional isolation box (extra-large)
• A tub of Microworm starter culture (they only had one; I wanted three)
• A tub of Banana worm starter culture
• Brine shrimp eggs (5g)

I went to a grocery store and got the following things:

• Pronutro (maize porridge cereal)
• Black Pantyhose/stockings (the cheapest I could find)
• Yeast

I used the isolation box as a short emergency measure while I prepared separate homes. A divided box inside the same aquarium is not a long-term setup for the adults because they share water, have little territory, and can remain stressed by seeing each other.

I thought of using the microworm starter in the beginning stages of the baby fry as they are tiny and would be easy for the babies to eat. Unfortunately, they only had one tub, so I got the Banana worm starter as an extra. The brine shrimp eggs will be the first live food in time for the babies, as the worms will still take a few days to get going properly.

The cereal and yeast I got I will use to get the worm cultures going properly. The black stockings I used to cover the bottom part of the filter in my Betta tank. The bottom part of my filter is where the water of the tank gets sucked into, and I don’t want any babies getting sucked up. If you have an old pair, you can cut the toe part off and use it.

A sponge filter is safer for fry than an uncovered power-filter intake. A new sponge does not provide a mature biofilter, so seed it with media from a known healthy aquarium or cycle it before use. The aquarium bacteria guide explains the safe options. Cover an existing intake with fine aquarium foam or mesh and check it often for reduced flow.

How Does The Egg-Laying Process Start?

The egg-laying process starts with the male building a beautiful bubble nest. Sometimes, females also build nests, but theirs aren’t as impressive as the male’s bubble nest. Spawning will occur with the male and female, and it looks like he wraps his body around the female in quite an aggressive embrace. Unfortunately, I missed all this.

As he embraces her, eggs are released, and he swims to catch them and place them in the bubbles. This embrace is continued with catching and placing eggs. Once they are done spawning, you must remove the female from the tank or tub (if you were trying to breed with them). The male sees any other fish as a potential threat to his babies as he catches eggs and places them back into the bubble nest.

The Betta eggs will hatch in a day or two (depending on the water temperature). The baby Betta fry will look like they are hanging from the bubbles or sitting on the side of the tank. The male will continue to scoop them up with his mouth and place them back near the bubbles.

Newly hatched fry use their yolk sac while they remain near the nest. Remove the male when the fry become free-swimming, not simply at a set number of hours. Have his separate aquarium ready before that point.

What I Did After The Eggs Hatched

I prepared the live food at once because cultures take time to start. In a planned setup, each adult needs a separate heated and filtered home before pairing. After an accidental spawn, temporary containers require close temperature and water-quality checks until proper aquariums are ready.

I forgot to mention that the male Betta, busy caring for babies and everything, will most likely not eat anything during this time. It is completely normal. Once separated for a few hours, he will start eating again.

What To Feed The Fry

Once the yellow egg sack of the Betta fry has been depleted, usually on day two or three, you can start feeding your fry. You have many options to start with. People like using Vinegar Eels (you can also purchase a starter culture of this), baby Brine Shrimp, or Microworms to start with.

You can progress to other tiny live foods as the fry grow, such as banana worms, newly hatched brine shrimp, Daphnia, and Grindal worms when the fry are large enough. Keep the parents out of the nursery after the fry become free-swimming.

Feed very small portions that the fry can finish, remove waste, and test ammonia and nitrite daily. Rotate suitable foods for nutrition and supply, but judge each food by the fry’s mouth size rather than the calendar alone.

Green Of GloBetta Plakat Fry Already Visible On TailsBetta fry have very small stomachs and can only eat a bit at once. Therefore, it is best to add only a little bit at a time when adding live food to the tank. You can feed your Betta fry their very small, wiggly meals three to five times daily.

I have started all my cultures to provide me with a supply of live food for the baby fry. Most people plan when they want their Bettas to spawn and plan ahead with live food available when the baby Betta fry hatch. I will definitely continue with all my live food, as live food is great nutrition for adult Bettas and my other fish. For larger juveniles and adults, I would also keep Tubifex worms in mind.