Temporal and sex-specific patterns of breeding territory defense in a color-polymorphic cichlid fish

In biparental species, the costs and benefits of parental investment can vary between the sexes and shift over time. However, such sex-specific and temporal changes in territory defense are not well understood. Here, we experimentally investigated parental investment in breeding territory defense in a feral population of the color-polymorphic, biparental cichlid fish, the red devil (Amphilophus labiatus). We presented either gold- or dark-colored conspecific intruder models (i.e., dummy models) to A. labiatus pairs at three key stages during the breeding cycle (i.e., after pair formation, after eggs have been laid, and when fry were free-swimming). We found that males were more aggressive when the pair first formed, whereas females significantly increased their territory defense with time, and were most aggressive when fry were free-swimming. These results show that parental roles in territory defense can markedly shift over key stages of the breeding cycle. Our results demonstrate that parental behaviors may not only vary between the sexes, but can also shift dramatically over the course of the brood cycle.