Like humans families that depend on everyone pulling their weight, cichlid fish have arguments when childcare and housework are not shared.
A cichlid fish without babies who wants to be part of a family group must help out with childcare (guarding fry, cleaning eggs) and defending the territory. If they are lazy they may be punished by the dominant breeders or may even be expelled from the territory.
Cichlid fish are cooperative breeders, who resemble humans in some aspects of their social life, and it seems that, like humans families that depend on everyone pulling their weight, cichlid fish have arguments when childcare and housework are not shared. This combination of conflict and cooperation can be seen in various animal families and it is particularly interesting to study in animals who breed cooperatively.
Because individuals in these groups work together to raise the youngsters, which can be hard work even if every member of the groups helps, they depend on each other. They often have to work harder when the group is small or when certain individuals are reluctant to contribute. This can create a situation where some group members get in conflict over the levels of help other individuals should provide. Conflict among siblings, between parents and offspring, and among individuals providing care for the offspring is common and can be surprisingly tough. For example, young hyenas occasionally kill their sibling when food is scarce to monopolise maternal care, and by doing that achieve faster growth rates.
Cooperatively breeding animals live in family groups that resemble the structure and organisation of human families in some important aspects. Often only one male and one female reproduce and all other group members provide help with raising the offspring of the breeding pair. Frequently, but not always, the helping individuals are offspring from previous breeding who have delayed their departure from their parental group, forgo their own reproduction, and assist with providing for and guarding their younger siblings. Other examples in addition to the cichlid fish are meerkats, naked mole-rats, long-tailed tits and some species of bee-eaters. Whereas many of the cooperatively breeding birds live in relatively small groups (often only the pair and one helper), mole-rat groups can reach very large sizes with more than 200 non-reproductive helpers.