Satiation restores brood care motivation in the female mouthbrooder Pseudocrenilabrus multicolor (Cichlidae)

The maternal mouthbrooder Pseudocrenilabrus multicolor takes up her eggs during spawning and carries them continuously in her mouth for 10-11 days at 27 degrees C. Then the young-by that time able to swim-are released from the mouth. The duration of mouthbrooding is controlled by an internal timing program in the mother [12]. In non-first-spawners brood care motivation (= readiness to take up brood into the mouth and keep it there) disappears within a few hours after brood removal. At the same time hunger-which is reduced to half of the normal level when brood care motivation is present-increases to the normal level [15]. In females without brood care motivation, satiation by food intake or by a water solution of 15 mg/l diethylpropion (an anorectic amphetamine-derivative), restores brood care motivation during a sensitive period of approximately 11 days after spawning. The point of release of adopted brood from the mouth depends on the duration of previous brood deprivation, but not on the state of brood care motivation nor on the hunger state during brood deprivation. The results suggest that above a certain level hunger inhibits brood care motivation. By contrast, the hunger state seems not to influence internal timing of mouthbrooding.