OFFSPRING QUALITY AND FEMALE CHOICE IN THE GUPPY, POECILIA-RETICULATA

This study evaluated the offspring viability prediction of the conditi on-dependent and Fisherian models of female choice in the guppy. Famil ies of full-sibling females were bred with the male they preferred or did not prefer in a choice experiment. The physical condition, sexual behaviour and coloration of the offspring were evaluated. There were n o significant differences between offspring attributable to the type o f sire. However, there were significant family and sire-type by family interactions for physical condition, male mating behaviour and colora tion. These significant effects indicate that consistency within famil ies may be due to genetic effects. Genetic analyses indicate that gene tic variation probably exists for prolonged swimming performance, phys ical condition and display rate. The results of this study and other s tudies on other fish have shown that these measures of constitution ar e correlated with components of viability. These results are interpret ed in the framework of the condition-dependent and Fisherian models of female choice.