Optimal offspring size influenced by the interaction between dissolved oxygen and predation pressure

Question: How does optimal size at the beginning of the juvenile stage vary with dissolved oxygen and aquatic predator pressure? Mathematical methods: An implicit model based on earlier offspring size and number optimality models, using empirical observations to motivate and interpret the results. Key assumptions: A stable, density-independent system with high parental care that maximizes maternal fitness, with respect to offspring size and number. Predictions: The model predicts a positive relationship between juvenile size and aquatic dissolved oxygen, with respect to maternal fitness and predation pressure. This prediction is based on observations in the literature that smaller fish are less sensitive to low dissolved oxygen and may use low dissolved oxygen habitats as predator refuges.