Cover: The physics of turbulent mixing of fluids plays an integral role in many ecological processes, including reproduction. For example, mixing affects the coalescence of initially distant gametes released by broadcast spawning benthic invertebrates (see article by J. P. Crimaldi, pp. 1031−1039). Colors in the image show the concentration distribution of surrogates for eggs (red) and sperm (blue) in turbulent laboratory flow. The complex interplay between structured stirring of gametes (at larger scales) and sperm motility and taxis (at smaller scales) is critical in determining the efficacy of the overall fertilization strategy. Image courtesy of Michael Soltys and John Crimaldi.