Photosynthetic Animal

A. Markov, in *The Birth of Complexity*, describes the mollusc *Elysia viridis*, which is capable of transferring chloroplasts from the algae it consumes into its own cells. By retaining them alive for a prolonged period, it acquires the ability to photosynthesize. And here is a news item about a mollusc from the same genus that has gone even further along the path of horizontal gene transfer with its food. In this context, I have a question: 1. Is this not the largest and most structurally complex animal capable of autonomous photosynthesis? 2. And what other such animal organisms of the mesoworld exist?