Effects of parental care on resource allocation into immune defence and buccal microbiota in mouthbrooding cichlids; cellular immune paramenter (flow cytometry), candidate gene expression (Fluidigm), buccal microbiota composition (MySeq, Illumina)

In conventional parental care roles, males maximize their lifetime reproductive success by allocating resources towards sexual selection, while females achieve this through prolonging their lifespan. Here, we examine the interrelation between sexual dimorphism and parental care strategies in closely related maternal and biparental mouthbrooding cichlid fishes from East African Lake Tanganyika.

We measured cellular immune parameters, examined the relative expression of 28 immune system and life-history-related candidate genes and analysed the microbiota composition in the buccal cavity. According to our predictions, maternal mouthbrooders are more sexually dimorphic in immune parameters and buccal microbiota composition than biparental mouthbrooders, which has possibly arisen through a differential resource allocation into parental care versus secondary sexual traits.