Brood care is common among cichlid fish. In mouthbrooding species, one parent (usually the female)
holds the offspring in the mouth for extended periods of time. This behaviour implies a prolonged depression of the hyoid and an expansion
of the suspensoria (increasing the mouth cavity). However, in fish, the hyoid and the suspensorium make up the buccal pump, which, in concert
with the opercular pump, guarantees respiration. The obvious question arises whether the presence of developing brood affects the functioning
and efficiency of the respiratory system. This master thesis entails a kinesiological study of respiration in female cichlids at different stages of
the breeding period. The study species is Oreochromis niloticus.