This project tested the effects of water conditions on developmental rates of larvae of the estuarine sea anemone Nematostella vectensis . Egg masses were collected immediately following fertilization and placed in solutions with different salinities and maintained in a temperature-controlled water bath. Every twelve hours, embryonic development was checked for progression through different morphological stages of development. Comparison of regression analyses of larval development at each temperature increment indicated that both temperature and salinity affected the rate of development; development was slower in lower conditions and faster at higher salinities and temperatures, with extreme conditions inducing deleterious effects. The suggested ideal conditions for these larvae are a salinity range of 12.5--20% and a temperature range of 22--24C. These parameters provide a foundation from which a standardized testing method may be established, using N. vectensis larval development.