How Often Do Mouthbrooding Fish Spawn?

Most fish are absentee parents -- they breed, then abandon their fertilized eggs to fend for themselves. African cichlids and many species of bettas have evolved a more hands-on approach to parenting: After mating, one parent holds the fertilized eggs in its mouth until they hatch. The young fry live inside the parent's mouth until they're big enough to fend for themselves. In the wild, this results in a higher chance of survival for the fry. In an aquarium setting, mouthbrooders are easy to breed and fascinating to observe.

  1. Cichlid Versus Betta Mouthbrooders

    • Mouthbrooders are divided into parental mouthbrooders and maternal mouthbrooders. Cichlids are maternal mouthbrooders: The mother cichlid keeps the eggs and the fry in her mouth until they reach maturity. Bettas are paternal mouthbrooders: The father betta holds the eggs and the fry while the mother betta goes free.

    Breeding Triggers

    • Unlike other animals that have seasonal mating cycles, the mating frequency of mouthbreeding fish is determined by their environment. Both cichlids and bettas breed during the start of the rainy season, and will respond to similar cues in an aquarium environment.

      The best way to simulate the coming of the monsoon, and therefore prompt your cichlids or bettas to breed, is with water changes. An influx of clean, slightly cooler water imitates the effect of a rainstorm and will make your fish think the rainy season has begun. Frequent water changes can be accompanied by flashing lights and deep bass noises to imitate thunder.

      Ensure that your tank has a lot of hiding places, such as flower pots, and spawning sites such as flat, clean rocks. Accompany your water changes with high-quality food. When cichlids and bettas experience these cues, breeding should commence quickly and spontaneously.

    Mouthbrooding Frequency

    • Because mouthbrooding is cued by environmental triggers, not body cycles, it can happen at any time. In theory, mouthbrooders could breed over and over without stopping -- the mouthbrooding parent should be ready to mate very quickly after it has released the fry.

      Mouthbrooding betta fathers usually release the fry after seven to 10 days of holding them in his mouth. Once the betta fry are spit out, they are left to their own devices -- in fact, the father may even eat some of the fry as soon as he spits them out.

      Cichlid mothers are more cautious. It takes about four to six weeks for the mother to fully separate from the fry. Even after the fry have hatched and the mother has spit them out, they will stay near her for some time, and rush back inside her mouth at the first sign of danger. By about six weeks, the fry will move off on their own and the mother will rejoin the other cichlids.

    Limits on Frequency

    • The are two main limits on breeding frequency of mouthbrooders: the health of the mouthbrooding parent and the female's fertility.

      Breeding can't happen unless there's a female with eggs ready. In a tank with a medium-sized population, there will usually be several females ready to mate at any given time. Immature females cannot breed, and are often difficult to distinguish from their mature counterparts -- so in a small-tank population, breeding may proceed slowly until more females reach maturity.

      The other limiter is the health of the mouthbrooding parent. Because the mouthbrooding mother or father does not eat while mouthbrooding, it emerges from the brooding process weakened and hungry. It's best to give the new mother or father some time to recover; if forced to breed again too soon, it may starve to death or immediately consume all the fry once they hatch.