This activity would benefit the sea slugs with chloroplasts as they can be able to synthesize some of their own food. Sea slugs are marine invertebrates that feed on algae, plankton and decaying matter in water. When some sea slugs ingest algae, they store chloroplasts obtained from the algae into their own digestive cells. Chloroplast is an organelle that contains chlorophyll (green pigment) used in photosynthesis. The chloroplasts continue to perform photosynthesis within the sea slugs and hence, keeping them nourished.