On the Cover: The green pigmentation present in the photosynthetic sea slug Elysia chlorotica is the result of juvenile animals feeding on and engulfing chloroplasts from the siphonaceous, chromophytic marine alga Vaucheria litorea (seen in the background). The chloroplasts are maintained intracellularly in specific cells lining the digestive diverticula and remain functional for at least 9 months despite the absence of any detectable algal nuclei or nuclear DNA. In the Update by Rumpho et al. (pp. 29–38), historical and recent advances in understanding chloroplast/mollusc symbioses are reviewed. (Image by M. Rumpho with digital enhancement by R.D. Lineberger, Texas A&M University.)