Bettas breed in two distinctly different ways. Species such as Betta picta are mouthbrooders. The male picks up the fertilized eggs and carries them in his mouth until the fry hatch and are swimming freely. Other Bettas, such as the familiar Betta splendens and Betta imbellis build bubblenests. The male fish takes the most responsibility here as well. He builds the bubblenest and guards the eggs until they hatch and are free swimming. As the average hobbyist will be dealing with Betta splendens fish rather than mouthbrooders, we will be focusing on this type of breeding for this page.
Betta splendens live in more stagnant waters and as such, they build nests. The eggs that Bettas produce are heavier than water and they sink to the bottom of the aquarium. When male and female Bettas mate, the male squeezes the female in an embrace to expel the eggs. After the female has expelled all her eggs, the male catches them before they sink to the bottom and spits them into the floating raft of bubbles he has built. This amusing game of catching and spitting will continue until all of the females eggs have been expelled. At this time the female should be removed from the spawning tank.
A single spawning can produce hundreds of eggs; as many as 300 eggs. The eggs will hatch in about 2 days. During this time the male Betta will tend the nest and retrieve any eggs that may fall to the bottom of the aquarium. The male Betta should be removed from the breeding tank after the hatching is completed.
Selecting Breeding Stock
To start, you may want to breed inexpensive Bettas so you can get the hang of the basics involved in setting up the breeding tank and introducing potential partners. This way you won't be risking expensive fish on beginner mistakes. This does not mean you should limit yourself to purchasing only two Bettas. If you have the space, you should purchase at least 3 males and 3 females. This will give you several pairings to work with at the same time.
If you are keeping a large number of males for breeding, space can quickly become a consideration. While it is not financially feasible to keep each male in its own 10 gallon tank, you still want to provide the best care possible to your stock. You can usually group females together into one tank provided that each has enough space and lots of hiding places.
Male Betta should be housed in individual 3-6 gallon tanks, with heaters and filters. You can also have them in large (2 gallon or larger) containers or jars, with the understanding that these jars will need almost daily water changes and will need to be in a room heated to at least 76 degrees Fahrenheit.
If your chosen female has battled with disease, before spawning she may not be able to produce strong, viable eggs which will develop normally. Even though fry can be produce from eggs like this, the resulting fry will often be deformed or have abnormalities. It is important that your spawning females be in perfect health and free from disease and parasites before they are used for breeding.
Setting Up a Breeding Tank
A 10 gallon aquarium is a good starter size for a breeding tank because it allows you to keep careful track of the bubblenest , spawning rituals and fry. It also gives the female more room to escape from the male if there was a mistake made and the pair were introduced too early. All parts of the breeding aquarium (glass, equipment etc) should be carefully cleaned with hot water and sterilized in a salt solution to prevent any lingering bacteria or fungus being introduced to the eggs and newborn fry.
An aquarium cover or lid will ensure that your spawning Bettas do not jump the tank and will prevent debris from entering the water. A cover will also provide protection for the eggs and fry by keeping warm moist air in the tank, which is important for the development of the labyrinthine organ.
Spawning Bettas are sometimes aggressive, it is wise to purchase several thick plants for the breeding tank. These plants help to provide privacy, can be used in the construction of the bubblenest, and will also offer shelter to the female if necessary. Hornwort, is my favorite choice of plant for a breeding tank.
Providing plants and hiding places among which your female Betta can hide will give her and the male fish an opportunity to get acquainted before spawning. If no hiding places are in the breeding tank, the male Betta may kill the female out of territorial instinct before any spawning can take place. I like to use PVC pipe junctions and corners in the 2 inch size for hiding places, as they are inexpensive, and easy to sanitize with boiling water.
It is best to leave the bottom of the aquarium bare, with no rocks. If you are worried about your fish being disoriented, you can paint the outside of the bottom of the aquarium with flat black paint or put it on a dark colored towel or surface to simulate a bottom. Leaving the bottom of the aquarium bare, allows for easy retrieval of any eggs or fry that may fall from the bubblenest after spawning by the male.
Water conditions should be the same type of conditions you already keep your Betta in now, PH of between 6.8 and 7 and hardness of the water should be between 8 and 10. You can create these conditions by using 50% tap water and 50% reverse osmosis or demineralized water. For a large operation breeding Bettas, you may want to invest in a reverse osmosis unit. The temperature of the water in the Betta tank should be a steady 82 degrees Fahrenheit and should be monitored closely with your thermometer. If the temperature rises above 85 degrees, the eggs may be severely damaged by the excess heat. The water level of the tank should be no more than 6 -7 inches deep. This allows lots of room for warm, moist air which will be kept in by your aquarium lid.
Water turbulence may disturb the bubblenest and make it difficult for the male to keep the eggs and fry in the nest. I personally use a sponge filter to breed Bettas with an adjustable air pump turned to a low setting to minimize water surface disturbance. This filter should have been pre-seeded with beneficial bacteria by placing it in the female Betta tank during breeding conditioning. If you don't have an adjustable air pump, you can purchase a gang valve and install it, or tie a knot in the air line tubing between the air pump and the air stone in your sponge filter to help reduce the water turbulence. You can also opt to use no filter at all, but in this case, water parameters should be monitored daily with water changes every day or every other day.
Some Bettas will breed with no encouragement; others seem to have a hard time figuring out what they're doing. Although there is no foolproof method, you can try several tricks to attempt to encourage your Bettas to spawn.
Water changes are very important, not only for the health of your Betta, but it can be vital in your Bettas success in spawning. In nature, seasonal rains are the signal which marks the start of the breeding season. Water in the wild becomes softer as it is diluted with fresh rainwater, and the nitrogen level begins to drop.
You can duplicate this effect by doing frequent water changes (about 15 to 20 percent per day for breeding). Use reverse osmosis or demineralized water to help stimulate the Bettas to enter their spawning cycle.
An increase in barometric pressure will also condition your Bettas for breeding. Many hobbyists have reported that their Bettas were more interested in breeding right before or during a rain or snowstorm. You can follow the local weather reports and choose your breeding time appropriately.
The rainy season can be duplicated by showering the surface of the aquarium when doing your water changes by using a watering can or a (brand new) kitchen colander or strainer.
Another common change in the natural environment during breeding season is a sudden abundance of food. Insects are more active and abundant during wet and rainy seasons, as are fresh water invertebrates.
Offer your potential breeders live brine shrimp, or blackworms to condition them for breeding. When feeding frozen or live foods, ensure that you continue the daily use of their regular diet as well. Live foods are a supplement to the balanced diet you already provide for good health and successful spawning.
If you have a male that is reluctant to breed, you might try introducing a second male in a jar and placing the rival near the spawning tank. When the first Betta realizes that there may be competition for his female he might be more inspired to breed.
Introducing Bettas to the Breeding Tank
Add the male to the breeding tank first. Attach a Styrofoam cup cut in half lengthwise to the side of the tank. The idea is to get the cup floating on the open side (length-wise) in order to create a little cave. If you keep the top of the cups opening pointed to the front of the tank, it will be easier to assess the progress of the male's bubblenest construction. If the male doesn't build a bubblenest within a few days time, check to see if the water movement may be too much for him. Otherwise, he may not be in prime breeding condition. If the male appears healthy, the water movement seems fine and everything else seems good, do a 10% water change with cooler water. Often this will spur him to get ready to spawn. Also, a regular day and night cycle with lights on timers should be kept to.
Once the bubblenest construction has begun, it's time to take a look at the female. She should be about the same size or even slightly smaller than the male, and her ovipositor should be visible if she's ready to breed. The ovipositor is an easily seen small white protrusion coming from the belly of the fish, just behind the anal opening. If this is not present or she does not look full of eggs, she should be conditioned further before breeding is attempted. Another sign for the female is three dark vertical bars on her body. These should not be confused with the horizontal stress bars that some females exhibit.
If the male and female both appear ready to mate, then it's time to introduce the pair. For first time breeders, you will want to do this while you have a weekend or several days in a row available, so that you can monitor the pair. There are multiple methods of doing this, but I use a chimney from an oil lamp to keep the female safe during the introduction. The male should show interest, and then continue constructing his nest. If this is the case, release the female while he is building. She should have hiding places within the plants to avoid him for now. If they appear to be overly aggressive, or the male will not leave the chimney alone to go back to building his bubblenest, they're not ready to spawn yet. Remove the female and condition them a little longer.
Once the male and female are in the tank, very slowly raise the temperature over a few days to about 82-85 degrees. This rise in temperature will tell the fish that it is time to consider spawning. Spawning should occur within 2-3 days, if not a few hours after the temperature rise has begun. If the fish don't spawn within a few days, it is probably best to remove the female and possibly look for another one. If she attempts to go near the bubblenest but is consistently chased away, the male is not ready.
While constructing his bubblenest, the male Betta will guard the territory immediately around it. If he chases the female all around the tank, or does not build a bubblenest, he is not ready to spawn, or you may need to look for a different male.
Once the female approaches the bubblenest and is not immediately chased away, the spawning is not far from happening. The male will wrap himself around the female, who will release the eggs. The male will catch the eggs on his tail where they are fertilized. He will then pick up the falling eggs and place them up in his bubblenest. The female will be stunned for a few moments after each embrace. This can be alarming to the beginning breeder, don't be alarmed, she will come around. Once she does comes around, she will attempt to eat any non-collected eggs. Spawning can last from a few minutes to a few hours. Once the female starts running from the male instead of falling into the embrace, it is time to remove her. This is so she will not eat the eggs or fry, and to avoid any unnecessary damage from the male. She should be left on her own for at least a week, being fed good foods and kept warm before placing her back in any community or sorority aquarium.
Caring for the Eggs
The male now assumes all care of the eggs and fry. He will collect any eggs that may fall out, as well as any wrigglers once the eggs hatch. This is why we keep the bottom clear of gravel and decorations. It would be very difficult for the male to dig fry from 2" of rocks. Hatching should occur within 48-72 hours. Intense light can be harmful to the eggs as can a lack of oxygen; so during this time, it is best to keep lighting in the aquarium to a minimum, and preform twice daily water changes, being very careful not to disturb the bubble nest.
Caring for the Fry
Once the fry are free-swimming and moving around on their own without yolk sacs attached, it is time to remove the male. Make sure he's well fed and taken care of, as this experience will be quite draining to him.
Betta fry are tiny and should be fed with liquefied foods once their yolk sacs have been absorbed. I like to use infusoria cultures and feed with an eye-dropper. At approximately 1 week, switch to baby brine shrimp. You may lose a few fish with this switch, but only the small fish unable to eat the artemia will be lost. This is a simple way to cull the smallest fish from the brood. Fry grow quickly and need food to keep up with this growth; they should be fed 3 to 5 times daily. Within a few weeks, you can switch to larger foods and still larger.
During this time, it is important to keep up with daily 50% water changes. This helps to eliminate stunting in the smaller specimens due to the abundance of waste in the water. Also, slowly raise the water level from half full, up to the top of the aquarium. Make sure you are using clean water that is the same temperature and pH as the water that is already in the aquarium. As part of your daily maintenance for this tank, carefully inspect your brood for fish which are malformed and humanely destroy them.
During this period, the labyrinth organ is still developing and the fry will be using their gills to breathe. As the organ develops, you will see them start to head to the surface and take gulps of air.
At approximately 3 months of age it is important to do a third round of culls. This round of culls is mainly based on color, but it is also important to keep a lookout for proper development and form. Be ruthless. Keep only those fish which have the qualities you are interested in for your next round of breeding. This round of culls does not need to be destroyed unless there is some major deformity in an individual specimen that was previously missed. Instead these can be sold as pets to a pet store or as pets on a website like http://www.aquabid.com/. Please do not advertise your culls as breeder quality fish on any website. A fish that does not fit perfectly into your breeding program will still make a beautiful pet for someone.
At approximately 3 months of age, it will be important to separate the sexes to minimize losses of the fry. Females can be kept together in increasingly large grow-out tanks. Don't leave females out of your culling. Pick only the best to keep and sell the rest off.
The easiest thing to do for the males at this time, is to put males into individual bowls, or jars of at least 2 gallons in your well heated breeding room and do daily water changes while you decide which of them you wish to keep for your future breeding purposes. Once you have made your selections, (try to make this period as short as possible) move the ones you would like to keep to permanent filtered, heated tanks, which are decorated at your discretion.