mouthbrooders

Mouthbrooding is a form of parental care in which one or both parents retain fertilized eggs or early life stages in the mouth for protection and respiration until the offspring are ready to survive independently. The approach reduces predation risk for the eggs but constrains the parent’s ability to feed during incubation.

Two main modes exist: maternal mouthbrooding, where the female incubates the eggs; paternal mouthbrooding, where the male incubates; and in some species care is biparental, with both parents participating at different times.

Mouthbrooding occurs in several fish groups. The most well-known examples are African cichlids, where females (and in some species males) carry eggs in the mouth. Other documented mouthbrooders include cardinalfishes (Apogonidae), certain damselfishes, and jawfishes (Opistognathidae), with paternal mouthholding reported in some cases, such as jawfish.

During spawning, eggs are taken into the mouth and kept there for an incubation period that can range from about a week to several weeks, depending on the species. When incubation ends, the parent releases free-swimming fry. In some species, the parent may continue to provide some early life-stage care, including occasional feeding of the fry by regurgitation, though this varies widely.

Mouthbrooding offers protection from predators and variable nesting sites but can limit the parent’s growth and future fecundity due to reduced feeding during incubation. The strategy has evolved multiple times across different lineages, illustrating diverse solutions to reproductive challenges in both freshwater and marine environments. In aquarium settings, mouthbrooding species are valued for their distinctive reproduction and maternal or paternal behaviors.