This project collects the genomic and transcriptomic data generated for Elysia crispata, common name lettuce slug, to facilitate genome assembly and annotation as part of the Aquatic Symbiosis Genomics (ASG) Project (https://www.aquaticsymbiosisgenomics.org/) from samples supplied by the ASG Photosymbiosis Hub (https://www.aquaticsymbiosisgenomics.org/collaborators/photosymbiosis-across-the-eukaryotic-tree-of-life/). The data under this project are made available subject to the Tree of Life Open Data Release Policy (https://www.darwintreeoflife.org/project-resources/).