Comparative life history research: growth, reproduction, and survival in Lake Tanganyika cichlids

Life history theory predicts that certain traits will co-evolve due to fundamental trade-offs, such that, for example, an organism that produces relatively large offspring has relatively few of them. Unveiling ecological factors that impact the balancing of such trade-offs is of great interest to evolutionary biologists, but sufficiently detailed data remain scarce. We argue that cichlids offer fruitful opportunities for comparative studies of the interplay between ecology and life history. We provide a dataset of highly detailed records of various life history traits for 7 species of Lake Tanganyika cichlids in support of this claim, comprising more than 400 clutches and almost 3000 individual fish. Our focal species are ecologically diverse but closely related and often co-occur in their natural habitats. We show that despite these commonalities they greatly differ in their patterns of growth, reproduction, and survival, even under controlled laboratory conditions. These fish may thus prove useful for investigating the ecological factors determining life history trait co-evolution.