Elysia chlorotica
Elysia chlorotica, commonly known as the emerald green sea slug, is a species of sacoglossan sea slug renowned for its ability to perform photosynthesis through a process called kleptoplasty. It sequesters functional chloroplasts from the algae it consumes, specifically Vaucheria litorea, and integrates them into its own digestive gland cells. This symbiotic relationship allows the slug to survive for months on sunlight alone, effectively blurring the line between animal and plant physiology.
Biological Mechanism
- Kleptoplasty: Unlike most animals that digest chloroplasts, E. chlorotica retains them. The chloroplasts remain functional within the slug’s cells, producing sugars that nourish the host.
- Nuclear Transfer Hypothesis: Research suggests that E. chlorotica may incorporate algal nuclear genes into its own genome to maintain chloroplast function, a rare example of horizontal gene transfer in animals.
- Longevity of Plastids: The sequestered chloroplasts can remain functional for up to 10 months, far longer than in other kleptoplastic species.
Recent Developments & Related Research
- Mammalian Applications: Emerging research in 2026 explores extending photosynthetic capabilities beyond invertebrates. See Photosynthesis in Mammalian Cells for Disease Treatment: 2026 Breakthrough for details on attempts to introduce photosynthesis into mammalian cells for therapeutic purposes.
- Bio-hybrid Systems: The success of E. chlorotica serves as a model for engineering bio-hybrid systems where animal cells utilize plant organelles for energy production.