ABSTRACT. – Larval fish are small and vulnerable, but can they improve their survival chance through adaptive behavioral strategies? Most theoretical models linking larval success to environmental conditions use oceanography, the physical environment and prey supply as the sole determinants of survival and growth. Here we review our recent model developments, which are based on the assumption that larval fish are like most other animals, hungry for food, afraid of predators, and equipped with cognitive abilities to respond to and make use of gradients and fluctuations in their environment. We explain and discuss differences between individual-based models and optimality models, and summarize some key predictions. We also point at the need for experimental studies to reveal the behavioral capacities of larval fish, both in the lab and in the ocean.